Toxic epidermal necrolysis is a severe and potentially life-threatening form of erythema multiforme. This condition leads to the detachment of the dermis from the lower layers of the skin. In some cases, it can result in death due to sepsis and failure of multiple organs.

Stevens-Johnson syndrome and toxic epidermal necrolysis are considered to be different stages of the same mucocutaneous disease, with toxic epidermal necrolysis being more severe. The degree of epidermal detachment is used to differentiate between the two conditions. In Stevens-Johnson syndrome, less than 10% of the body surface area is affected by epidermal detachment, while in toxic epidermal necrolysis, it is greater than 30%. An overlap syndrome occurs when the detachment is between 10-30% of the body surface area.

Certain medications can trigger Stevens-Johnson syndrome and toxic epidermal necrolysis. These include tetracyclines, penicillins, vancomycin, sulphonamides, NSAIDs, and barbiturates. It is important to be aware of these potential triggers and seek medical attention if any symptoms or signs of these conditions develop.

Eczema herpeticum occurs when an individual with atopic eczema comes into contact with the herpes simplex virus. While some patients may only experience typical cold sores, others may develop a more extensive infection. This condition is often accompanied by systemic disturbance and can be quite painful. Administering antiviral treatment can help reduce the duration of the illness. In cases where the rash is widespread or there are concerns about eye complications, hospital admission may be necessary for intravenous antiviral therapy.

Dermovate (Clobetasol propionate) is a strong steroid used for treating skin conditions. It is important to continue using emollients alongside steroid treatment. If the flare-ups are not effectively controlled by steroids, Tacrolimus can be considered as a secondary treatment option.

Further Reading:

Eczema is a chronic inflammatory skin disease characterized by dry, itchy skin with eczematous lesions. It often follows a chronic relapsing course and can lead to chronic skin changes such as lichenification and pigment changes. The term eczema is often used interchangeably with dermatitis, but strictly speaking, dermatitis refers to inflammation of the skin while eczema refers to specific conditions where skin inflammation is a feature.

Atopic eczema, also known as atopic dermatitis, is the most common type of eczema. It is usually first diagnosed in young children, with 90% of cases diagnosed before the age of 5. However, it can affect individuals of any age. Symptoms often improve as patients progress into their teens and adulthood. Around 10-20% of children are affected by atopic eczema, but only 3% of adults experience symptoms.

The exact cause of atopic eczema is not fully understood, but it is believed to be multifactorial, with both genetic and environmental factors playing a role. Genetic defects in genes that aid in the functioning of the skin barrier have been identified, which may predispose individuals to breaks in the skin barrier and increased exposure to antigens. Environmental factors such as pollution, allergen exposure, climate, and others also contribute to the development of the disease.

Diagnosing atopic eczema involves assessing the presence of key clinical features, such as pruritus (itching), eczema/dermatitis in a pattern appropriate for age, early age of onset, and personal or family history of atopy. Various diagnostic criteria have been established to aid in the diagnosis, including those set out by the American Academy of Dermatology and the UK working party.

The severity of atopic eczema can vary, and treatment options depend on the severity. Mild cases may be managed with emollients (moisturizers) and mild potency topical corticosteroids. Moderate cases may require moderate potency topical corticosteroids, topical calcineurin inhibitors, and bandages. Severe cases may necessitate the use of potent topical corticosteroids, topical calcineurin inhibitors, bandages, phototherapy, and systemic therapy.

In addition to medical treatment, identifying and avoiding triggers is an important aspect of managing atopic eczema. Common triggers include irritants, contact allergens, certain foods, skin infections, inhalant triggers, stress and infection.

Methicillin-resistant Staphylococcus aureus (MRSA) has become a significant issue in hospitals and other healthcare facilities in recent years. MRSA refers to any strain of Staphylococcus aureus that has developed resistance to beta-lactam antibiotics, such as penicillins and cephalosporins. This resistance is caused by the presence of the mecA gene, which produces a penicillin-binding protein with low affinity. Fortunately, MRSA is typically susceptible to teicoplanin, vancomycin, daptomycin, and linezolid. On the other hand, imipenem is an intravenous beta-lactam antibiotic that belongs to the carbapenem subgroup.

Acne conglobata is an extremely severe form of acne where acne nodules come together and create sinuses. Acne fulminans, on the other hand, is a rare and severe complication of acne conglobata that is accompanied by systemic symptoms. It is linked to elevated levels of androgenic hormones, specific autoimmune conditions, and a genetic predisposition.

The typical clinical characteristics of acne fulminans are as follows:

– Sudden and abrupt onset
– Inflammatory and ulcerated nodular acne primarily found on the chest and back
– Often painful lesions
– Ulcers on the upper trunk covered with bleeding crusts
– Severe acne scarring
– Fluctuating fever
– Painful joints and arthropathy
– General feeling of illness (malaise)
– Loss of appetite and weight loss
– Enlarged liver and spleen (hepatosplenomegaly)

It is crucial to refer patients immediately for a specialist evaluation and hospital admission. Treatment options for acne fulminans include systemic corticosteroids, dapsone, ciclosporin, and high-dose intravenous antibiotics.

Pemphigus, derived from the Greek word for bubble ‘pemphix’, refers to a group of autoimmune disorders that cause blistering of the skin and/or mucosal surfaces. The most common subset is pemphigus vulgaris (PV), which accounts for approximately 70% of cases worldwide. PV is characterized by an autoimmune response where autoantibodies target cell surface antigens on keratinocytes, specifically desmogleins 1 and 3. This leads to a loss of cell-to-cell adhesion and separation, resulting in blister formation.

On the other hand, bullous pemphigoid (BP) is a chronic autoimmune blistering skin disorder that affects the subepidermal layer. It occurs when the basement membrane of the epidermis is attacked by IgG and sometimes IgE immunoglobulins, as well as activated T lymphocytes. The binding of autoantibodies to proteins and the release of cytokines from T cells trigger complement activation, neutrophil recruitment, and the release of proteolytic enzymes. These enzymes destroy the hemidesmosomes, leading to the formation of subepidermal blisters.

To summarize the differences between pemphigus vulgaris and bullous pemphigoid, the following provides a comparison:

Pemphigus Vulgaris:
– Age: Middle-aged people (mean age 50)
– Oral involvement: Common
– Blister type: Large, flaccid, and painful
– Blister content: Fluid-filled, often haemorrhagic
– Areas commonly affected: Initially face and scalp, then spread to the chest and back
– Nikolsky sign: Usually positive
– Pruritus: Rare
– Skin biopsy: Intra-epidermal deposition of IgG between cells throughout the epidermis

Bullous Pemphigoid:
– Age: Elderly people (mean age 80)
– Oral involvement: Rare
– Blister type: Large and tense
– Blister content: Fluid-filled
– Areas commonly affected: Upper arms, thighs, and skin flexures
– Nikolsky sign: Usually negative
– Pruritus: Common
– Skin biopsy: A band of IgG and/or C3 at the dermo-epidermal junction

In the UK, the most commonly used treatment for acute exacerbations of hereditary angioedema (HAE) in emergency departments is C1-Esterase inhibitor. However, there are alternative options available. Icatibant acetate, sold under the brand name Firazyr®, is a bradykinin receptor antagonist that is licensed in the UK and Europe and can be used as an alternative treatment. Another alternative is the transfusion of fresh frozen plasma.

Further Reading:

Angioedema and urticaria are related conditions that involve swelling in different layers of tissue. Angioedema refers to swelling in the deeper layers of tissue, such as the lips and eyelids, while urticaria, also known as hives, refers to swelling in the epidermal skin layers, resulting in raised red areas of skin with itching. These conditions often coexist and may have a common underlying cause.

Angioedema can be classified into allergic and non-allergic types. Allergic angioedema is the most common type and is usually triggered by an allergic reaction, such as to certain medications like penicillins and NSAIDs. Non-allergic angioedema has multiple subtypes and can be caused by factors such as certain medications, including ACE inhibitors, or underlying conditions like hereditary angioedema (HAE) or acquired angioedema.

HAE is an autosomal dominant disease characterized by a deficiency of C1 esterase inhibitor. It typically presents in childhood and can be inherited or acquired as a result of certain disorders like lymphoma or systemic lupus erythematosus. Acquired angioedema may have similar clinical features to HAE but is caused by acquired deficiencies of C1 esterase inhibitor due to autoimmune or lymphoproliferative disorders.

The management of urticaria and allergic angioedema focuses on ensuring the airway remains open and addressing any identifiable triggers. In mild cases without airway compromise, patients may be advised that symptoms will resolve without treatment. Non-sedating antihistamines can be used for up to 6 weeks to relieve symptoms. Severe cases of urticaria may require systemic corticosteroids in addition to antihistamines. In moderate to severe attacks of allergic angioedema, intramuscular epinephrine may be considered.

The management of HAE involves treating the underlying deficiency of C1 esterase inhibitor. This can be done through the administration of C1 esterase inhibitor, bradykinin receptor antagonists, or fresh frozen plasma transfusion, which contains C1 inhibitor.

In summary, angioedema and urticaria are related conditions involving swelling in different layers of tissue. They can coexist and may have a common underlying cause. Management involves addressing triggers, using antihistamines, and in severe cases, systemic corticosteroids or other specific treatments for HAE.

The primary cause of roseola is the human herpesvirus 6B (HHV6B), with the human herpesvirus 7 (HHV7) being a less common cause.

Further Reading:

Roseola infantum, also known as roseola, exanthem subitum, or sixth disease, is a common disease that affects infants. It is primarily caused by the human herpesvirus 6B (HHV6B) and less commonly by human herpesvirus 7 (HHV7). Many cases of roseola are asymptomatic, and the disease is typically spread through saliva from an asymptomatic infected individual. The incubation period for roseola is around 10 days.

Roseola is most commonly seen in children between 6 months and 3 years of age, and studies have shown that as many as 85% of children will have had roseola by the age of 1 year. The clinical features of roseola include a high fever lasting for 2-5 days, accompanied by upper respiratory tract infection (URTI) signs such as rhinorrhea, sinus congestion, sore throat, and cough. After the fever subsides, a maculopapular rash appears, characterized by rose-pink papules on the trunk that may spread to the extremities. The rash is non-itchy and painless and can last from a few hours to a few days. Around 2/3 of patients may also have erythematous papules, known as Nagayama spots, on the soft palate and uvula. Febrile convulsions occur in approximately 10-15% of cases, and diarrhea is commonly seen.

Management of roseola is usually conservative, with rest, maintaining adequate fluid intake, and taking paracetamol for fever being the main recommendations. The disease is typically mild and self-limiting. However, complications can arise from HHV6 infection, including febrile convulsions, aseptic meningitis, and hepatitis.

Kaposi’s sarcoma (KS) is a type of cancer that affects the connective tissues. It is caused by a virus called human herpesvirus 8 (HHV-8). This cancer is more likely to occur in individuals with weakened immune systems, such as those with HIV or those who have undergone organ transplants.

The main symptom of KS is the development of skin lesions. These lesions initially appear as red-purple spots and quickly progress to become raised bumps and nodules. They can appear on any part of the body, but are most commonly found on the lower limbs, back, face, mouth, and genital area.

This child has been clinically diagnosed with measles. The typical presentation includes a high fever accompanied by symptoms of a runny nose and sensitivity to light. Conjunctivitis, or pink eye, is often present as well. The associated rash is a widespread red rash with raised bumps. Koplik spots, which are white lesions on the inside of the cheeks, are a telltale sign of measles.

According to Public Health England, it is recommended that children with measles stay away from school, nursery, or childminders for four days starting from when the rash first appears.

For more information, you can refer to the Guidance on Infection Control in Schools and other Childcare Settings.
https://www.publichealth.hscni.net/sites/default/files/Guidance_on_infection_control_in%20schools_poster.pdf

Public Health England advises that children with impetigo should not attend school, nursery, or be under the care of childminders until the sores have formed a crust or until 48 hours after starting antibiotic treatment. Antibiotics help accelerate the healing process and decrease the period of contagiousness.

For more information, please refer to the Guidance on Infection Control in Schools and other Childcare Settings.
https://www.publichealth.hscni.net/sites/default/files/Guidance_on_infection_control_in%20schools_poster.pdf

Cellulitis is a common cause of swelling in one leg. It is characterized by red, hot, tender, and swollen skin, usually affecting the shin on one side. Other symptoms may include fever, fatigue, and chills. It is important to consider deep vein thrombosis (DVT) as a possible alternative diagnosis, as it can be associated with cellulitis or vice versa. Unlike cellulitis, DVT does not typically cause fever and affects the entire limb below the blood clot, resulting in swelling in the calf, ankle, and foot. Necrotizing fasciitis is a rare condition. Gout primarily affects the joints of the foot, particularly the first metatarsophalangeal joint. Erythema migrans usually produces a distinct target-shaped rash.

Further Reading:

Cellulitis is an inflammation of the skin and subcutaneous tissues caused by an infection, usually by Streptococcus pyogenes or Staphylococcus aureus. It commonly occurs on the shins and is characterized by symptoms such as erythema, pain, swelling, and heat. In some cases, there may also be systemic symptoms like fever and malaise.

The NICE Clinical Knowledge Summaries recommend using the Eron classification to determine the appropriate management of cellulitis. Class I cellulitis refers to cases without signs of systemic toxicity or uncontrolled comorbidities. Class II cellulitis involves either systemic illness or the presence of a co-morbidity that may complicate or delay the resolution of the infection. Class III cellulitis is characterized by significant systemic upset or limb-threatening infection due to vascular compromise. Class IV cellulitis involves sepsis syndrome or a severe life-threatening infection like necrotizing fasciitis.

According to the guidelines, patients with Eron Class III or Class IV cellulitis should be admitted for intravenous antibiotics. This also applies to patients with severe or rapidly deteriorating cellulitis, very young or frail individuals, immunocompromised patients, those with significant lymphedema, and those with facial or periorbital cellulitis (unless very mild). Patients with Eron Class II cellulitis may not require admission if the necessary facilities and expertise are available in the community to administer intravenous antibiotics and monitor the patient.

The recommended first-line treatment for mild to moderate cellulitis is flucloxacillin. For patients allergic to penicillin, clarithromycin or clindamycin is recommended. In cases where patients have failed to respond to flucloxacillin, local protocols may suggest the use of oral clindamycin. Severe cellulitis should be treated with intravenous benzylpenicillin and flucloxacillin.

Overall, the management of cellulitis depends on the severity of the infection and the presence of any systemic symptoms or complications. Prompt treatment with appropriate antibiotics is crucial to prevent further complications and promote healing.

Slapped cheek syndrome, also known as fifth disease or erythema infectiosum, is caused by parvovirus B19. It is most commonly seen in children aged 4-12, but can affect individuals of any age. In the UK, the peak occurrence of this condition is in April and May. Slapped cheek syndrome is contagious, with the period of infectivity occurring before the appearance of the characteristic rash. The rash itself is painless.

Diagnosing slapped cheek syndrome is typically based on clinical presentation, characterized by the sudden onset of bright red cheeks resembling a slap mark. In some cases, a faint rash may also appear on other parts of the body. The rash usually lasts for a few days, but in rare instances, it may persist for a few weeks. Treatment for this condition is usually focused on managing symptoms. Additional symptoms that may accompany the rash include a mild fever and joint pain.

While slapped cheek syndrome is generally mild and resolves on its own, certain groups of individuals require extra caution. Pregnant women, for instance, are at an increased risk of miscarriage if exposed to fifth disease. Patients with sickle cell disease or weakened immune systems also need to take extra precautions.

The explanation states that the increased activity of the enzyme kininogenase is caused by hormonal factors, specifically oestrogen, as well as genetic factors.

Further Reading:

Angioedema and urticaria are related conditions that involve swelling in different layers of tissue. Angioedema refers to swelling in the deeper layers of tissue, such as the lips and eyelids, while urticaria, also known as hives, refers to swelling in the epidermal skin layers, resulting in raised red areas of skin with itching. These conditions often coexist and may have a common underlying cause.

Angioedema can be classified into allergic and non-allergic types. Allergic angioedema is the most common type and is usually triggered by an allergic reaction, such as to certain medications like penicillins and NSAIDs. Non-allergic angioedema has multiple subtypes and can be caused by factors such as certain medications, including ACE inhibitors, or underlying conditions like hereditary angioedema (HAE) or acquired angioedema.

HAE is an autosomal dominant disease characterized by a deficiency of C1 esterase inhibitor. It typically presents in childhood and can be inherited or acquired as a result of certain disorders like lymphoma or systemic lupus erythematosus. Acquired angioedema may have similar clinical features to HAE but is caused by acquired deficiencies of C1 esterase inhibitor due to autoimmune or lymphoproliferative disorders.

The management of urticaria and allergic angioedema focuses on ensuring the airway remains open and addressing any identifiable triggers. In mild cases without airway compromise, patients may be advised that symptoms will resolve without treatment. Non-sedating antihistamines can be used for up to 6 weeks to relieve symptoms. Severe cases of urticaria may require systemic corticosteroids in addition to antihistamines. In moderate to severe attacks of allergic angioedema, intramuscular epinephrine may be considered.

The management of HAE involves treating the underlying deficiency of C1 esterase inhibitor. This can be done through the administration of C1 esterase inhibitor, bradykinin receptor antagonists, or fresh frozen plasma transfusion, which contains C1 inhibitor.

In summary, angioedema and urticaria are related conditions involving swelling in different layers of tissue. They can coexist and may have a common underlying cause. Management involves addressing triggers, using antihistamines, and in severe cases, systemic corticosteroids or other specific treatments for HAE.

Flucloxacillin is recommended as the initial treatment for mild cellulitis, according to NICE guidelines. The recommended dosage for flucloxacillin is 500-1000 mg taken four times a day for a period of 5-7 days. However, if a patient is allergic to penicillin or if flucloxacillin is not suitable for them, alternative medications such as clarithromycin, doxycycline, or erythromycin can be used as second-line options. It is important to note that for cellulitis near the eyes, co-amoxiclav is advised as the first-line treatment, while for cellulitis in patients with lymphedema who do not require hospital admission, amoxicillin is recommended as the first-line treatment.

Further Reading:

Cellulitis is an inflammation of the skin and subcutaneous tissues caused by an infection, usually by Streptococcus pyogenes or Staphylococcus aureus. It commonly occurs on the shins and is characterized by symptoms such as erythema, pain, swelling, and heat. In some cases, there may also be systemic symptoms like fever and malaise.

The NICE Clinical Knowledge Summaries recommend using the Eron classification to determine the appropriate management of cellulitis. Class I cellulitis refers to cases without signs of systemic toxicity or uncontrolled comorbidities. Class II cellulitis involves either systemic illness or the presence of a co-morbidity that may complicate or delay the resolution of the infection. Class III cellulitis is characterized by significant systemic upset or limb-threatening infection due to vascular compromise. Class IV cellulitis involves sepsis syndrome or a severe life-threatening infection like necrotizing fasciitis.

According to the guidelines, patients with Eron Class III or Class IV cellulitis should be admitted for intravenous antibiotics. This also applies to patients with severe or rapidly deteriorating cellulitis, very young or frail individuals, immunocompromised patients, those with significant lymphedema, and those with facial or periorbital cellulitis (unless very mild). Patients with Eron Class II cellulitis may not require admission if the necessary facilities and expertise are available in the community to administer intravenous antibiotics and monitor the patient.

The recommended first-line treatment for mild to moderate cellulitis is flucloxacillin. For patients allergic to penicillin, clarithromycin or clindamycin is recommended. In cases where patients have failed to respond to flucloxacillin, local protocols may suggest the use of oral clindamycin. Severe cellulitis should be treated with intravenous benzylpenicillin and flucloxacillin.

Overall, the management of cellulitis depends on the severity of the infection and the presence of any systemic symptoms or complications. Prompt treatment with appropriate antibiotics is crucial to prevent further complications and promote healing.

Erythroderma is a condition characterized by widespread redness affecting more than 90% of the body surface. It is also known as exfoliative erythroderma due to the presence of skin exfoliation. Another term used to describe this condition is the red man syndrome.

The clinical features of exfoliative erythroderma include the rapid spread of redness to cover more than 90% of the body surface. Scaling of the skin occurs between days 2 and 6, leading to thickening of the skin. Despite the skin feeling hot, patients often experience a sensation of coldness. Keratoderma, which is the thickening of the skin on the palms and soles, may develop. Over time, erythema and scaling of the scalp can result in hair loss. The nails may become thickened, ridged, and even lost. Lymphadenopathy, or enlarged lymph nodes, is a common finding. In some cases, the patient’s overall health may be compromised.

Exfoliative erythroderma can be caused by various factors, including eczema (with atopic dermatitis being the most common underlying cause), psoriasis, lymphoma and leukemia (with cutaneous T-cell lymphoma and Hodgkin lymphoma being the most common malignant causes), certain drugs (more than 60 drugs have been implicated, with sulphonamides, isoniazid, penicillin, antimalarials, phenytoin, captopril, and cimetidine being the most commonly associated), idiopathic (unknown cause), and rare conditions such as pityriasis rubra pilaris and pemphigus foliaceus. Withdrawal of corticosteroids, underlying infections, hypocalcemia, and the use of strong coal tar preparations can also precipitate exfoliative erythroderma.

Potential complications of exfoliative erythroderma include dehydration, hypothermia, cardiac failure, overwhelming secondary infection, protein loss and edema, anemia (due to loss of iron, B12, and folate), and lymphadenopathy.

Management of exfoliative erythroderma should involve referring the patient to the medical on-call team and dermatology for admission. It is important to keep the patient warm and start intravenous fluids, such as warmed 0.9% saline. Applying generous amounts of emollients and wet dressings can help alleviate

Shingles, also known as herpes zoster, occurs when the varicella zoster virus becomes active again in a specific area of the skin. This results in a rash characterized by clusters of fluid-filled blisters or vesicles on a red base. Over time, these blisters will dry up and form crusts before eventually healing.

Further Reading:

Chickenpox is caused by the varicella zoster virus (VZV) and is highly infectious. It is spread through droplets in the air, primarily through respiratory routes. It can also be caught from someone with shingles. The infectivity period lasts from 4 days before the rash appears until 5 days after the rash first appeared. The incubation period is typically 10-21 days.

Clinical features of chickenpox include mild symptoms that are self-limiting. However, older children and adults may experience more severe symptoms. The infection usually starts with a fever and is followed by an itchy rash that begins on the head and trunk before spreading. The rash starts as macular, then becomes papular, and finally vesicular. Systemic upset is usually mild.

Management of chickenpox is typically supportive. Measures such as keeping cool and trimming nails can help alleviate symptoms. Calamine lotion can be used to soothe the rash. People with chickenpox should avoid contact with others for at least 5 days from the onset of the rash until all blisters have crusted over. Immunocompromised patients and newborns with peripartum exposure should receive varicella zoster immunoglobulin (VZIG). If chickenpox develops, IV aciclovir should be considered. Aciclovir may be prescribed for immunocompetent, non-pregnant adults or adolescents with severe chickenpox or those at increased risk of complications. However, it is not recommended for otherwise healthy children with uncomplicated chickenpox.

Complications of chickenpox can include secondary bacterial infection of the lesions, pneumonia, encephalitis, disseminated haemorrhagic chickenpox, and rare conditions such as arthritis, nephritis, and pancreatitis.

Shingles is the reactivation of the varicella zoster virus that remains dormant in the nervous system after primary infection with chickenpox. It typically presents with signs of nerve irritation before the eruption of a rash within the dermatomal distribution of the affected nerve. Patients may feel unwell with malaise, myalgia, headache, and fever prior to the rash appearing. The rash appears as erythema with small vesicles that may keep forming for up to 7 days. It usually takes 2-3 weeks for the rash to resolve.

Management of shingles involves keeping the vesicles covered and dry to prevent secondary bacterial infection.

Bullous pemphigoid (BP) is a chronic autoimmune disorder that affects the skin, causing blistering. It occurs when the immune system mistakenly attacks the basement membrane of the epidermis. This attack is carried out by immunoglobulins (IgG and sometimes IgE) and activated T lymphocytes. The autoantibodies bind to proteins and release cytokines, leading to complement activation, neutrophil recruitment, and the release of enzymes that destroy the hemidesmosomes. As a result, subepidermal blisters form.

Pemphigus, on the other hand, is a group of autoimmune disorders characterized by blistering of the skin and mucosal surfaces. The most common type, pemphigus vulgaris (PV), accounts for about 70% of cases worldwide. PV is also autoimmune in nature, with autoantibodies targeting cell surface antigens on keratinocytes (desmogleins 1 and 3). This leads to a loss of adhesion between cells and their separation.

Here is a comparison of the key differences between pemphigus vulgaris and bullous pemphigoid:

Pemphigus vulgaris:
– Age: Middle-aged people (average age 50)
– Oral involvement: Common
– Blister type: Large, flaccid, and painful
– Blister content: Fluid-filled, often haemorrhagic
– Areas commonly affected: Initially face and scalp, then spread to the chest and back
– Nikolsky sign: Usually positive
– Pruritus: Rare
– Skin biopsy: Intra-epidermal deposition of IgG between cells throughout the epidermis

Bullous pemphigoid:
– Age: Elderly people (average age 80)
– Oral involvement: Rare
– Blister type: Large and tense
– Blister content: Fluid-filled
– Areas commonly affected: Upper arms, thighs, and skin flexures
– Nikolsky sign: Usually negative
– Pruritus: Common
– Skin biopsy: A band of IgG and/or C3 at the dermo-epidermal junction

The initial stage of SJS is characterized by a rash on the skin, specifically on the macular area. As the condition progresses, the rash transforms into blisters, known as bullae, which eventually detach from the skin.

Further Reading:

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are severe mucocutaneous immune reactions characterized by blistering skin rash and erosions/ulceration of mucous membranes. SJS has less than 10% total body surface area (TBSA) involvement, SJS/TEN overlap has 10% to 30% TBSA involvement, and TEN has more than 30% TBSA involvement. The exact cause of SJS and TEN is not well understood, but it is believed to be a T-cell–mediated cytotoxic reaction triggered by drugs, infections, or vaccinations. Drugs are responsible for 50% of SJS cases and up to 95% of TEN cases, with antibiotics and anticonvulsants being the most common culprits.

The clinical features of SJS and TEN include a prodrome of malaise, fever, headache, and cough, followed by the appearance of small pink-red macules with darker centers. These macules can coalesce and develop into larger blisters (bullae) that eventually break and cause the epidermis to slough off. Painful mucosal erosions can also occur, affecting various parts of the body and leading to complications such as renal failure, hepatitis, pneumonia, and urethritis. Nikolsky’s sign, which refers to the easy sloughing off of the epidermal layer with pressure, is a characteristic feature of SJS and TEN.

The diagnosis of SJS, SJS/TEN overlap, and TEN can be confirmed through a skin biopsy, which typically shows desquamation at the epidermal-papillary dermal junction and the presence of necrotic epithelium and lymphocytes. Management of SJS and TEN involves supportive care, withdrawal of the causative agent if drug-related, monitoring for metabolic derangement and infection, maintaining the airway, treating respiratory function and pneumonia, fluid resuscitation, wound care, analgesia, and nutritional support. Ophthalmology consultation is also recommended. Intravenous immunoglobulin, ciclosporin, corticosteroids, and plasmapheresis may be used in treatment, but there is limited evidence supporting their effectiveness.

The prognosis of SJS and TEN can be assessed using the SCORTEN score, which comprises of 7 clinical and biological parameters, with the predicted probability of mortality ranging from 3.2% to 90.0%.

Stevens-Johnson syndrome is a severe and potentially deadly form of erythema multiforme. It can be triggered by anything that causes erythema multiforme, but it is most commonly seen as a reaction to medication within 1-3 weeks of starting treatment. Initially, there may be symptoms like fever, fatigue, joint pain, and digestive issues, followed by the development of severe mucocutaneous lesions that are blistering and ulcerating.

Stevens-Johnson syndrome and toxic epidermal necrolysis are considered to be different stages of the same mucocutaneous disease, with toxic epidermal necrolysis being more severe. The extent of epidermal detachment is used to differentiate between the two. In Stevens-Johnson syndrome, less than 10% of the body surface area is affected by epidermal detachment, while in toxic epidermal necrolysis, it is greater than 30%. An overlap syndrome occurs when detachment affects between 10-30% of the body surface area.

Several drugs can potentially cause Stevens-Johnson syndrome and toxic epidermal necrolysis, including tetracyclines, penicillins, vancomycin, sulphonamides, NSAIDs, and barbiturates.

Chickenpox is a highly contagious illness caused by the varicella-zoster virus, a DNA virus from the Herpesviridae family. Most cases are mild to moderate, and the infection usually resolves on its own. Severe complications are rare but can occur, especially in individuals with weakened immune systems or underlying health conditions.

The incubation period for chickenpox is typically between 14 to 21 days. It is contagious from a few days before the rash appears until about a week after the first lesions show up.

The common clinical features of chickenpox include:

– Fever, which lasts for approximately 3-5 days.
– The initial rash starts as flat red spots and progresses into raised bumps.
– These bumps then turn into fluid-filled blisters and eventually form pustules surrounded by redness.
– The lesions are extremely itchy.
– The rash reaches its peak around 48 hours in individuals with a healthy immune system.
– The rash tends to be more concentrated on the face and trunk, with fewer lesions on the limbs.
– The blisters eventually dry up and form crusts, which can lead to scarring if scratched.
– Headache, fatigue, and abdominal pain may also occur.

Chickenpox tends to be more severe in teenagers and adults compared to children. Antiviral treatment should be considered for these individuals if they seek medical attention within 24 hours of rash onset. The recommended oral dose of aciclovir is 800 mg taken five times a day for seven days.

Immunocompromised patients and those at higher risk, such as individuals with severe cardiovascular or respiratory disease or chronic skin disorders, should receive antiviral treatment for ten days, with at least seven days of intravenous administration.

Although most cases are relatively mild, if serious complications like pneumonia, encephalitis, or dehydration are suspected, it is important to refer the patient for hospital admission.

For more information, you can refer to the NICE Clinical Knowledge Summary on Chickenpox.
https://cks.nice.org.uk/topics/chickenpox/

Angioedema and urticaria are related conditions that involve swelling in different layers of tissue. Angioedema refers to swelling in the deeper layers of tissue, such as the lips and eyelids, while urticaria, also known as hives, refers to swelling in the epidermal skin layers, resulting in raised red areas of skin with itching. These conditions often coexist and may have a common underlying cause.

Angioedema can be classified into allergic and non-allergic types. Allergic angioedema is the most common type and is usually triggered by an allergic reaction, such as to certain medications like penicillins and NSAIDs. Non-allergic angioedema has multiple subtypes and can be caused by factors such as certain medications, including ACE inhibitors, or underlying conditions like hereditary angioedema (HAE) or acquired angioedema.

HAE is an autosomal dominant disease characterized by a deficiency of C1 esterase inhibitor. It typically presents in childhood and can be inherited or acquired as a result of certain disorders like lymphoma or systemic lupus erythematosus. Acquired angioedema may have similar clinical features to HAE but is caused by acquired deficiencies of C1 esterase inhibitor due to autoimmune or lymphoproliferative disorders.

The management of urticaria and allergic angioedema focuses on ensuring the airway remains open and addressing any identifiable triggers. In mild cases without airway compromise, patients may be advised that symptoms will resolve without treatment. Non-sedating antihistamines can be used for up to 6 weeks to relieve symptoms. Severe cases of urticaria may require systemic corticosteroids in addition to antihistamines. In moderate to severe attacks of allergic angioedema, intramuscular epinephrine may be considered.

The management of HAE involves treating the underlying deficiency of C1 esterase inhibitor. This can be done through the administration of C1 esterase inhibitor, bradykinin receptor antagonists, or fresh frozen plasma transfusion, which contains C1 inhibitor.

In summary, angioedema and urticaria are related conditions involving swelling in different layers of tissue. They can coexist and may have a common underlying cause. Management involves addressing triggers, using antihistamines, and in severe cases, systemic corticosteroids or other specific treatments for HAE.

Pityriasis versicolor, also known as tinea versicolor, is a common skin condition caused by an infection with the yeasts Malassezia furfur and Malassezia globosa. It typically presents as multiple patches of altered pigmentation, primarily on the trunk. In individuals with fair skin, these patches are usually darker in color, while in those with darker skin or a tan, they may appear lighter (known as pityriasis versicolor alba). It is not uncommon for the rash to cause itching.

The recommended treatment for pityriasis versicolor involves the use of antifungal agents. One particularly effective option is ketoconazole shampoo, which is sold under the brand name Nizoral. To use this shampoo, it should be applied to the affected areas and left on for approximately five minutes before being rinsed off. This process should be repeated daily for a total of five days.

Patients who have Eron class III or IV cellulitis should be hospitalized and treated with intravenous antibiotics. In this case, the patient is experiencing cellulitis along with symptoms of significant systemic distress, such as rapid heart rate and breathing. This places the patient in the Eron Class III category, which necessitates admission for intravenous antibiotic therapy.

Further Reading:

Cellulitis is an inflammation of the skin and subcutaneous tissues caused by an infection, usually by Streptococcus pyogenes or Staphylococcus aureus. It commonly occurs on the shins and is characterized by symptoms such as erythema, pain, swelling, and heat. In some cases, there may also be systemic symptoms like fever and malaise.

The NICE Clinical Knowledge Summaries recommend using the Eron classification to determine the appropriate management of cellulitis. Class I cellulitis refers to cases without signs of systemic toxicity or uncontrolled comorbidities. Class II cellulitis involves either systemic illness or the presence of a co-morbidity that may complicate or delay the resolution of the infection. Class III cellulitis is characterized by significant systemic upset or limb-threatening infection due to vascular compromise. Class IV cellulitis involves sepsis syndrome or a severe life-threatening infection like necrotizing fasciitis.

According to the guidelines, patients with Eron Class III or Class IV cellulitis should be admitted for intravenous antibiotics. This also applies to patients with severe or rapidly deteriorating cellulitis, very young or frail individuals, immunocompromised patients, those with significant lymphedema, and those with facial or periorbital cellulitis (unless very mild). Patients with Eron Class II cellulitis may not require admission if the necessary facilities and expertise are available in the community to administer intravenous antibiotics and monitor the patient.

The recommended first-line treatment for mild to moderate cellulitis is flucloxacillin. For patients allergic to penicillin, clarithromycin or clindamycin is recommended. In cases where patients have failed to respond to flucloxacillin, local protocols may suggest the use of oral clindamycin. Severe cellulitis should be treated with intravenous benzylpenicillin and flucloxacillin.

Overall, the management of cellulitis depends on the severity of the infection and the presence of any systemic symptoms or complications. Prompt treatment with appropriate antibiotics is crucial to prevent further complications and promote healing.

Onchocerciasis is a parasitic disease caused by the filarial nematode Onchocerca volvulus. It is transmitted through the bites of infected blackflies of Simulium species, which carry immature larval forms of the parasite from human to human.

In the human body, the larvae form nodules in the subcutaneous tissue, where they mature to adult worms. After mating, the female adult worm can release up to 1000 microfilariae a day.

Onchocerciasis is currently endemic in 30 African countries, Yemen, and a few isolated regions of South America. Approximately 37 million people worldwide are currently infected.

Symptoms start to occur around a year after the patient is infected. The earliest symptom is usually an intensely itchy rash. Various skin manifestations occur, including scattered, red, pruritic papules (acute papular onchodermatitis), larger, chronic, hyperpigmented papules (chronic papular onchodermatitis), lichenified, oedematous, hyperpigmented papules and plaques (lichenified onchodermatitis), areas of skin atrophy with loss of elasticity (‘Lizard skin’), and depigmented areas with a ‘leopard skin appearance, usually on shins.

Ocular involvement provides the common name associated with onchocerciasis, river blindness, and it can involve any part of the eye. Almost a million people worldwide have at least a partial degree of vision loss caused by onchocerciasis. Initially, there may be intense watering, foreign body sensation, and photophobia. This can progress to conjunctivitis, iridocyclitis, and chorioretinitis. Secondary glaucoma and optic atrophy may also occur.

In a number of countries, onchocerciasis has been controlled through spraying of blackfly breeding sites with insecticide. The drug ivermectin is the preferred treatment for onchocerciasis.

Many systemic illnesses have distinct dermatological associations. Some of these are listed below:

Addison’s disease is characterized by pigmentation and vitiligo.

Cushing’s disease is associated with pigmentation, striae, hirsutism, and acne.

Diabetes mellitus can cause necrobiosis lipoidica, which presents as shiny, yellowish plaques on the shin. It can also lead to xanthoma, a condition characterized by yellowish lipid deposits in the skin, and granuloma annulare, which manifests as palpable ring lesions on the hands, face, or feet.

Hyperlipidemia is linked to xanthoma and xanthomata, which are yellowish plaques on the eyelids.

Crohn’s disease is associated with erythema nodosum.

Ulcerative colitis can cause pyoderma gangrenosum and erythema nodosum.

Liver disease often presents with pruritus, spider naevi, and erythema.

Malignancy can lead to mycosis fungoides, a type of lymphoma that affects the skin. It is also associated with acanthosis nigricans, which is often seen in gastrointestinal malignancies.

Hypothyroidism is linked to alopecia, while thyrotoxicosis can cause both alopecia and pretibial myxedema.

Hand-foot-and-mouth disease is a viral syndrome characterized by a unique rash and sores. The main culprit behind this condition is typically the Coxsackie A16 virus. After being exposed to the virus, it takes about 3-5 days for symptoms to appear. The disease spreads through droplets in the air. Before the rash and sores develop, individuals may experience a pre-illness phase with symptoms like a sore throat and mouth ulcers. This condition primarily affects children under the age of ten. In addition to the rash, most children will also develop spots on their hands and feet.

When it comes to treatment, the focus is mainly on providing support. This involves using antipyretics to reduce fever and ensuring that the affected individual stays well-hydrated. Due to the mouth ulcers, loss of appetite is common, so it’s important to encourage adequate fluid intake.

Stevens-Johnson syndrome is a severe and potentially deadly form of erythema multiforme. It can be triggered by anything that causes erythema multiforme, but it is most commonly seen as a reaction to medication within 1-3 weeks of starting treatment. Initially, there may be symptoms like fever, fatigue, joint pain, and digestive issues, followed by the development of severe mucocutaneous lesions that are blistering and ulcerating.

Stevens-Johnson syndrome and toxic epidermal necrolysis are considered to be different stages of the same mucocutaneous disease, with toxic epidermal necrolysis being more severe. The extent of epidermal detachment is used to differentiate between the two. In Stevens-Johnson syndrome, less than 10% of the body surface area is affected by epidermal detachment, while in toxic epidermal necrolysis, it is greater than 30%. An overlap syndrome occurs when detachment affects between 10-30% of the body surface area.

Several drugs can potentially cause Stevens-Johnson syndrome and toxic epidermal necrolysis, including tetracyclines, penicillins, vancomycin, sulphonamides, NSAIDs, and barbiturates.

Systemic lupus erythematosus (SLE) is a connective tissue disorder that affects multiple systems in the body. It is characterized by skin rashes, joint pain, and the presence of antibodies against double-stranded DNA. SLE is more commonly seen in young women, with a ratio of 10 females to 1 male. It is also more prevalent in West Indian populations.

One of the classic signs of SLE is the presence of a butterfly rash. This rash appears as redness over the bridge of the nose and cheeks. It is often worsened by exposure to sunlight and can occur before other symptoms of SLE develop.

Joint involvement is common in SLE and can affect both large and small joints. The knee, proximal interphalangeal, wrist, and metacarpophalangeal joints are most frequently affected.

Atopic dermatitis is a long-lasting inflammatory skin condition that is linked to increased levels of IgE in the bloodstream. It is also characterized by sensitivity to various allergens found in the air, food, and microorganisms.

Further Reading:

Eczema is a chronic inflammatory skin disease characterized by dry, itchy skin with eczematous lesions. It often follows a chronic relapsing course and can lead to chronic skin changes such as lichenification and pigment changes. The term eczema is often used interchangeably with dermatitis, but strictly speaking, dermatitis refers to inflammation of the skin while eczema refers to specific conditions where skin inflammation is a feature.

Atopic eczema, also known as atopic dermatitis, is the most common type of eczema. It is usually first diagnosed in young children, with 90% of cases diagnosed before the age of 5. However, it can affect individuals of any age. Symptoms often improve as patients progress into their teens and adulthood. Around 10-20% of children are affected by atopic eczema, but only 3% of adults experience symptoms.

The exact cause of atopic eczema is not fully understood, but it is believed to be multifactorial, with both genetic and environmental factors playing a role. Genetic defects in genes that aid in the functioning of the skin barrier have been identified, which may predispose individuals to breaks in the skin barrier and increased exposure to antigens. Environmental factors such as pollution, allergen exposure, climate, and others also contribute to the development of the disease.

Diagnosing atopic eczema involves assessing the presence of key clinical features, such as pruritus (itching), eczema/dermatitis in a pattern appropriate for age, early age of onset, and personal or family history of atopy. Various diagnostic criteria have been established to aid in the diagnosis, including those set out by the American Academy of Dermatology and the UK working party.

The severity of atopic eczema can vary, and treatment options depend on the severity. Mild cases may be managed with emollients (moisturizers) and mild potency topical corticosteroids. Moderate cases may require moderate potency topical corticosteroids, topical calcineurin inhibitors, and bandages. Severe cases may necessitate the use of potent topical corticosteroids, topical calcineurin inhibitors, bandages, phototherapy, and systemic therapy.

In addition to medical treatment, identifying and avoiding triggers is an important aspect of managing atopic eczema. Common triggers include irritants, contact allergens, certain foods, skin infections, inhalant triggers, stress and infection.