Causes and diagnostic workup of systemic pruritus

Systemic pruritus, or generalized itching, can have various underlying causes, including pregnancy, primary biliary cholangitis, renal failure, diabetes, leukaemia, polycythaemia, psychological factors, and hypothyroidism. To diagnose the condition, blood tests are typically performed to rule out these potential causes. Hypothyroidism may be suspected if the patient also experiences weight gain and fatigue. Treatment for systemic pruritus involves addressing the underlying condition, as well as using measures such as keeping the skin cool, applying emollients, and taking sedating antihistamines at night.

Other conditions that may cause pruritus but are less likely in this case include iron deficiency anaemia, which typically presents with pallor rather than weight gain, and cholestasis, which usually causes jaundice, dark urine, and pale stool. Lymphoma, a type of cancer affecting the lymphatic system, may cause weight loss and lymphadenopathy rather than weight gain. Widespread dermatitis, characterized by a rash, is another possible cause of pruritus.

Medications that can worsen psoriasis

Psoriasis is a chronic skin condition that can be triggered or worsened by certain medications. Beta-blockers, commonly used to treat high blood pressure and heart conditions, are known to induce psoriasis or make existing psoriasis worse. Other medications that can exacerbate psoriasis include non-steroidal anti-inflammatory drugs, antimalarials, and lithium. These medications can contribute to erythrodermic and pustular eruptions, which can be severe and require medical attention. It’s important to note that reactions to these medications can occur anywhere from less than a month to a year after starting the medication. Additionally, tapering doses of steroids can also lead to a worsening of psoriasis symptoms.

Understanding Scabies Infestation

Scabies infestation is a skin condition caused by the Sarcoptes scabiei mite. It is commonly transmitted through close contact and is prevalent in nursing homes and other institutions. The primary symptom of scabies is severe itching, and if present, burrows (linear crusted lesions) and penile papules are highly suggestive. The condition typically affects the web-spaces and around the nipples, with scalp involvement only occurring in young babies and debilitated adults. Excoriations are also common.

The treatment for scabies usually involves the use of permethrin, and close contacts should be treated simultaneously. Atopic eczema is unlikely to present at this age, and chronic kidney disease and diabetes are associated with several skin conditions but do not typically cause pruritus. Iron-deficiency anaemia may cause pruritus, but it is rarely as severe as scabies.

Treatment Regime for Moderately Severe Eczema with Superimposed Infection

Moderately severe eczema with evidence of superimposed infection requires a specific treatment regime. The severity of eczema is categorized into four categories: clear, mild, moderate, and severe. In this case, the patient has small areas of dry skin mainly in the flexures, and there is evidence of infected eczema/cellulitis with an erythematosus, weeping patch of skin in the lateral thigh.

The treatment regime should include a regular emollient ointment, such as Diprobase®, applied generously to the skin multiple times a day. Additionally, a moderately potent topical corticosteroid, such as betamethasone valerate 0.025% or clobetasone butyrate 0.05%, should be used sparingly on the inflamed areas once a day. The patient must be advised to apply the steroid first and allow 15-20 minutes for it to be absorbed before applying the emollient. Treatment should last 7-14 days and continue until 48 hours after the eczematous patches have cleared.

Furthermore, oral antibiotics are necessary for the treatment of infected eczema. Oral flucloxacillin is considered first-line, and treatment usually lasts for a 10-day period.

Treatment Regime for Moderately Severe Eczema with Superimposed Infection

Differences and Similarities between Acne and Rosacea

Acne vulgaris and rosacea are two common skin conditions that affect the face. While they share some similarities, they also have distinct differences.

Acne vulgaris is characterized by a mixture of comedones, papules, pustules, nodules, and cysts. Comedones are formed when the cells lining the sebaceous duct proliferate excessively and block the duct. Open comedones are blackheads, while closed comedones are whiteheads. Other types of comedones include giant comedones and solar comedones. Acne vulgaris usually starts in puberty and can continue into adulthood.

On the other hand, rosacea is a chronic or intermittent rash that affects the central face. It is characterized by blushing or flushing and persistent redness and telangiectasia. Telangiectasias are small, dilated blood vessels that appear as red lines on the skin. Papules and pustules may also develop, and the skin may be dry and flaky. The nose may have prominent pores due to sebaceous gland hyperplasia.

While both acne and rosacea can present with papules, pustules, and crusting, comedones are a characteristic feature of acne and are not present in rosacea. Additionally, acne vulgaris usually starts in puberty and is more common in younger individuals, while rosacea typically affects those aged 30-60.

In summary, while acne and rosacea share some similarities in their presentation, they also have distinct differences that can help differentiate between the two conditions.

Common Skin Conditions and Their Causes

Erythema Nodosum: A subcutaneous inflammation, erythema nodosum is often associated with inflammatory bowel disease, tuberculosis, sarcoidosis, or a recent streptococcal infection. It is characterized by raised nodules on the lower extremities.

Morbilliform Rash: A mild hypersensitivity skin reaction, the morbilliform rash is a maculopapular eruption that blanches with pressure. It is caused by drugs such as penicillin, sulfonylurea, thiazide, allopurinol, and phenytoin.

Erythema Multiforme: A target-like lesion that commonly appears on the palms and soles, erythema multiforme is usually caused by drugs such as penicillins, phenytoin, NSAIDs, or sulfa drugs. It can also be caused by Mycoplasma or herpes simplex.

Tinea Corporis: A fungal infection, tinea corporis is characterized by ring-shaped, scaly patches with central clearing and a distinct border.

Urticaria: A hypersensitivity reaction that results in wheals and hives, urticaria is most often associated with drug-induced mast cell activation. Aspirin, NSAIDs, and phenytoin are common culprits.

Understanding Common Skin Conditions and Their Causes

Causes of Non-Scarring and Scarring Alopecia

Non-scarring alopecia is a condition where hair loss occurs without any visible scarring on the scalp. The most common causes of this type of alopecia include telogen effluvium, androgenetic alopecia, alopecia areata, tinea capitis, and traumatic alopecia. In some cases, non-scarring alopecia can also be associated with lupus erythematosus and secondary syphilis.

Tinea capitis, caused by invasion of hairs by dermatophytes, most commonly Trichophyton tonsurans, is a common cause of non-scarring alopecia. This type of alopecia is characterized by hair loss in circular patches on the scalp.

On the other hand, scarring alopecia is a condition where hair loss occurs with visible scarring on the scalp. This type of alopecia is more frequently the result of a primary cutaneous disorder such as lichen planus, folliculitis decalvans, cutaneous lupus, or linear scleroderma (morphea). Scarring alopecia can be permanent and irreversible, making early diagnosis and treatment crucial.

In conclusion, the different causes of non-scarring and scarring alopecia is important in determining the appropriate treatment plan for patients experiencing hair loss.

Importance of Biopsy in Diagnosing Melanoma

When a patient with type 1 or 2 skin presents with a pigmented lesion that is large and has multiple colors, it is suggestive of melanoma. It is crucial to inquire about any changes over time and symptoms such as bleeding or itching. A comprehensive medical history should include family history of skin cancers, risk factors such as sun exposure, hobbies, travel, sunburns as a child, previous skin cancers or abnormal moles, and history of immunosuppression. The ABCDE rule should be followed for suspicious pigmented lesions.

A biopsy is necessary for diagnosis and determining the prognosis of melanoma based on the Breslow depth. Clinical photographs and follow-up in 3 months may be appropriate in some cases, but if there is a suspicion of melanoma, an urgent biopsy is necessary. Scrapings for mycology are not useful in diagnosing pigmented lesions, and measuring ACE levels is not appropriate in this scenario.

In conclusion, a biopsy is essential in diagnosing melanoma and determining its prognosis. It is crucial to follow the ABCDE rule and obtain a comprehensive medical history to identify any risk factors. Early detection and prompt treatment can significantly improve the patient’s outcome.

Differentiating Causes of Hair Loss: A Guide

Hair loss can be a distressing experience, but it is important to identify the underlying cause in order to determine the appropriate treatment. Here are some common causes of hair loss and their distinguishing features:

Tinea Capitis: This fungal infection can cause abnormal scalp skin and alopecia. The affected area may be scaly or inflamed, and broken hairs do not taper at the base.

Alopecia Areata: This autoimmune disease results in circular areas of hair loss without scaling, inflammation, or broken hair.

Discoid Lupus Erythematosus: This condition causes red, scaly patches that leave white scars and permanent hair loss due to scarring alopecia.

Psoriasis: Thick scaling on the scalp may cause mild hair loss, but it does not result in permanent balding. Psoriasis may also be present elsewhere on the body.

Trichotillomania: Hair pulling disorder does not cause abnormalities to the scalp skin.

By understanding the distinguishing features of these causes of hair loss, prompt and appropriate treatment can be initiated to prevent permanent hair loss.

Differentiating Skin Rashes: A Comparison of Erythema Nodosum, Erythema Multiforme, Kaposi’s Sarcoma, Tinea Corporis, and Steven-Johnson’s Syndrome

Erythema nodosum is a rash characterized by painful red papules caused by inflammation of the subcutaneous fat. It is commonly seen on the extensor surfaces of the lower limbs and can be linked to various conditions such as streptococcal and tuberculous infection, inflammatory bowel disease, lymphoma, drug-related causes, and sarcoidosis.

Erythema multiforme, on the other hand, presents with typical target lesions on the extremities. It is an uncommon condition that can be mistaken for other skin rashes.

Kaposi’s sarcoma is an AIDS-defining malignancy caused by human herpes virus 8. It appears as red/purple papules on the skin or mucosal surfaces. However, the description of the rash, normal blood results, and an otherwise healthy patient make this diagnosis unlikely.

Tinea corporis, also known as ringworm, is a fungal infection transmitted from common pets or human-to-human. It presents as an erythematosus, scaly ring-like rash with central clearing.

Steven-Johnson’s syndrome is a severe form of erythema multiforme with multiple erythematosus macules on the face and trunk, epidermal detachment, and mucosal ulceration. It is a rare condition that can cause significant morbidity and mortality.

In summary, differentiating between these skin rashes is crucial for proper diagnosis and treatment. A thorough evaluation of the patient’s medical history, physical examination, and laboratory tests can help identify the underlying cause of the rash.