The shoulder abductor is the supraspinatus.

The shoulder joint is a shallow synovial ball and socket joint that is inherently unstable but capable of a wide range of movement. Stability is provided by the muscles of the rotator cuff. The glenoid labrum is a fibrocartilaginous rim attached to the free edge of the glenoid cavity. The fibrous capsule attaches to the scapula, humerus, and tendons of various muscles. Movements of the shoulder joint are controlled by different muscles. The joint is closely related to important anatomical structures such as the brachial plexus, axillary artery and vein, and various nerves and vessels.

Fractures involving the shaft can compromise the radial nerve, which is located in this groove.

The humerus is a long bone that runs from the shoulder blade to the elbow joint. It is mostly covered by muscle but can be felt throughout its length. The head of the humerus is a smooth, rounded surface that connects to the body of the bone through the anatomical neck. The surgical neck, located below the head and tubercles, is the most common site of fracture. The greater and lesser tubercles are prominences on the upper end of the bone, with the supraspinatus and infraspinatus tendons inserted into the greater tubercle. The intertubercular groove runs between the two tubercles and holds the biceps tendon. The posterior surface of the body has a spiral groove for the radial nerve and brachial vessels. The lower end of the humerus is wide and flattened, with the trochlea, coronoid fossa, and olecranon fossa located on the distal edge. The medial epicondyle is prominent and has a sulcus for the ulnar nerve and collateral vessels.

The axillary nerve is responsible for supplying the teres minor and deltoid muscles. It is composed of nerve fibers from C5 and C6 of the brachial plexus and originates in the axilla. The nerve exits the axilla through the quadrangular space, located at the lower border of the subscapularis muscle. It then travels medially to the surgical neck of the humerus, making it vulnerable to injury in cases of surgical neck fractures. Other muscles innervated by the axillary nerve include the teres major and trapezius, which are supplied by the lower subscapular and accessory nerves, respectively.

Upper limb anatomy is a common topic in examinations, and it is important to know certain facts about the nerves and muscles involved. The musculocutaneous nerve is responsible for elbow flexion and supination, and typically only injured as part of a brachial plexus injury. The axillary nerve controls shoulder abduction and can be damaged in cases of humeral neck fracture or dislocation, resulting in a flattened deltoid. The radial nerve is responsible for extension in the forearm, wrist, fingers, and thumb, and can be damaged in cases of humeral midshaft fracture, resulting in wrist drop. The median nerve controls the LOAF muscles and can be damaged in cases of carpal tunnel syndrome or elbow injury. The ulnar nerve controls wrist flexion and can be damaged in cases of medial epicondyle fracture, resulting in a claw hand. The long thoracic nerve controls the serratus anterior and can be damaged during sports or as a complication of mastectomy, resulting in a winged scapula. The brachial plexus can also be damaged, resulting in Erb-Duchenne palsy or Klumpke injury, which can cause the arm to hang by the side and be internally rotated or associated with Horner’s syndrome, respectively.

The superficial femoral nerve primarily provides cutaneous branches, but it also innervates the sartorius muscle.

The Sartorius Muscle: Anatomy and Function

The sartorius muscle is the longest strap muscle in the human body and is located in the anterior compartment of the thigh. It is the most superficial muscle in this region and has a unique origin and insertion. The muscle originates from the anterior superior iliac spine and inserts on the medial surface of the body of the tibia, anterior to the gracilis and semitendinosus muscles. The sartorius muscle is innervated by the femoral nerve (L2,3).

The primary action of the sartorius muscle is to flex the hip and knee, while also slightly abducting the thigh and rotating it laterally. It also assists with medial rotation of the tibia on the femur, which is important for movements such as crossing one leg over the other. The middle third of the muscle, along with its strong underlying fascia, forms the roof of the adductor canal. This canal contains important structures such as the femoral vessels, the saphenous nerve, and the nerve to vastus medialis.

In summary, the sartorius muscle is a unique muscle in the anterior compartment of the thigh that plays an important role in hip and knee flexion, thigh abduction, and lateral rotation. Its location and relationship to the adductor canal make it an important landmark for surgical procedures in the thigh region.

The Koebner phenomenon is a term used to describe the appearance of skin lesions at the site of injury. Patients with a history of psoriasis and recent skin trauma are at risk of developing this phenomenon, which can also occur in individuals with other skin conditions like warts and vitiligo. Lichen planus is another condition where the Koebner phenomenon is observed. In contrast, the Nikolsky phenomenon is a dermatological phenomenon seen in pemphigus vulgaris, where the epidermis can be moved over the dermis upon palpation. Psoriatic arthritis is a type of arthritis that affects some individuals with psoriasis, causing joint inflammation, pain, stiffness, and swelling.

The Koebner Phenomenon: Skin Lesions at the Site of Injury

The Koebner phenomenon refers to the occurrence of skin lesions at the site of injury. This phenomenon is commonly observed in various skin conditions such as psoriasis, vitiligo, warts, lichen planus, lichen sclerosus, and molluscum contagiosum. In other words, if a person with any of these skin conditions experiences trauma or injury to their skin, they may develop new lesions in the affected area.

This phenomenon is named after Heinrich Koebner, a German dermatologist who first described it in 1876. The exact mechanism behind the Koebner phenomenon is not fully understood, but it is believed to be related to the immune system’s response to injury. In some cases, the injury may trigger an autoimmune response, leading to the development of new lesions.

The Koebner phenomenon can be a frustrating and challenging aspect of managing skin conditions. It is important for individuals with these conditions to take precautions to avoid injury to their skin, such as wearing protective clothing or avoiding activities that may cause trauma. Additionally, prompt treatment of any new lesions that develop can help prevent further spread of the condition.

Patients with rheumatoid arthritis are believed to have a higher likelihood of developing atherosclerotic disorders, even if they are unaware of any pre-existing heart conditions or elevated cardiovascular risk. The underlying cause of this atherosclerosis is attributed to systemic inflammation, which is thought to expedite the progression of the disease.

Complications of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease that affects the joints, causing inflammation and pain. However, it can also lead to a variety of extra-articular complications. These complications can affect different parts of the body, including the respiratory system, eyes, bones, heart, and mental health.

Respiratory complications of RA include pulmonary fibrosis, pleural effusion, pulmonary nodules, bronchiolitis obliterans, methotrexate pneumonitis, and pleurisy. Ocular complications can include keratoconjunctivitis sicca, episcleritis, scleritis, corneal ulceration, keratitis, steroid-induced cataracts, and chloroquine retinopathy. RA can also lead to osteoporosis, ischaemic heart disease, and an increased risk of infections. Depression is also a common complication of RA.

Less common complications of RA include Felty’s syndrome, which is characterized by RA, splenomegaly, and a low white cell count, and amyloidosis, which is a rare condition where abnormal proteins build up in organs and tissues.

In summary, RA can lead to a variety of complications that affect different parts of the body. It is important for patients with RA to be aware of these potential complications and to work closely with their healthcare providers to manage their condition and prevent or treat any complications that may arise.

There are a total of 8 muscles that are involved in the movement of the thumb. These include two flexors, namely flexor pollicis brevis and flexor pollicis longus, two extensors, namely extensor pollicis brevis and longus, two abductors, namely abductor pollicis brevis and longus, one adductor, namely adductor pollicis, and one muscle that opposes the thumb by rotating the CMC joint, known as opponens pollicis. The flexor and extensor longus muscles are responsible for moving both the MCP and IP joints and insert on the distal phalanx.

Anatomy of the Hand: Fascia, Compartments, and Tendons

The hand is composed of bones, muscles, and tendons that work together to perform various functions. The bones of the hand include eight carpal bones, five metacarpals, and 14 phalanges. The intrinsic muscles of the hand include the interossei, which are supplied by the ulnar nerve, and the lumbricals, which flex the metacarpophalangeal joints and extend the interphalangeal joint. The thenar eminence contains the abductor pollicis brevis, opponens pollicis, and flexor pollicis brevis, while the hypothenar eminence contains the opponens digiti minimi, flexor digiti minimi brevis, and abductor digiti minimi.

The fascia of the palm is thin over the thenar and hypothenar eminences but relatively thick elsewhere. The palmar aponeurosis covers the soft tissues and overlies the flexor tendons. The palmar fascia is continuous with the antebrachial fascia and the fascia of the dorsum of the hand. The hand is divided into compartments by fibrous septa, with the thenar compartment lying lateral to the lateral septum, the hypothenar compartment lying medial to the medial septum, and the central compartment containing the flexor tendons and their sheaths, the lumbricals, the superficial palmar arterial arch, and the digital vessels and nerves. The deepest muscular plane is the adductor compartment, which contains adductor pollicis.

The tendons of the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) enter the common flexor sheath deep to the flexor retinaculum. The tendons enter the central compartment of the hand and fan out to their respective digital synovial sheaths. The fibrous digital sheaths contain the flexor tendons and their synovial sheaths, extending from the heads of the metacarpals to the base of the distal phalanges.

P-GO-GO-Q is a mnemonic for remembering the lateral hip rotators in order from top to bottom: Piriformis, Gemellus superior, Obturator internus, Gemellus inferior, Obturator externus, and Quadratus femoris.

Anatomy of the Hip Joint

The hip joint is formed by the articulation of the head of the femur with the acetabulum of the pelvis. Both of these structures are covered by articular hyaline cartilage. The acetabulum is formed at the junction of the ilium, pubis, and ischium, and is separated by the triradiate cartilage, which is a Y-shaped growth plate. The femoral head is held in place by the acetabular labrum. The normal angle between the femoral head and shaft is 130 degrees.

There are several ligaments that support the hip joint. The transverse ligament connects the anterior and posterior ends of the articular cartilage, while the head of femur ligament (ligamentum teres) connects the acetabular notch to the fovea. In children, this ligament contains the arterial supply to the head of the femur. There are also extracapsular ligaments, including the iliofemoral ligament, which runs from the anterior iliac spine to the trochanteric line, the pubofemoral ligament, which connects the acetabulum to the lesser trochanter, and the ischiofemoral ligament, which provides posterior support from the ischium to the greater trochanter.

The blood supply to the hip joint comes from the medial circumflex femoral and lateral circumflex femoral arteries, which are branches of the profunda femoris. The inferior gluteal artery also contributes to the blood supply. These arteries form an anastomosis and travel up the femoral neck to supply the head of the femur.

The fibular head serves as the insertion point for both the long and short head of the biceps femoris muscle.

Muscle Insertion Site
Sartorius Medial surface of the proximal tibia
Rectus femoris Tibial tuberosity
Biceps femoris Fibular head
Semimembranosus Medial tibial condyle
Pectineus

The Biceps Femoris Muscle

The biceps femoris is a muscle located in the posterior upper thigh and is part of the hamstring group of muscles. It consists of two heads: the long head and the short head. The long head originates from the ischial tuberosity and inserts into the fibular head. Its actions include knee flexion, lateral rotation of the tibia, and extension of the hip. It is innervated by the tibial division of the sciatic nerve and supplied by the profunda femoris artery, inferior gluteal artery, and the superior muscular branches of the popliteal artery.

On the other hand, the short head originates from the lateral lip of the linea aspera and the lateral supracondylar ridge of the femur. It also inserts into the fibular head and is responsible for knee flexion and lateral rotation of the tibia. It is innervated by the common peroneal division of the sciatic nerve and supplied by the same arteries as the long head.

Understanding the anatomy and function of the biceps femoris muscle is important in the diagnosis and treatment of injuries and conditions affecting the posterior thigh.

A fibular neck fracture can result in foot drop due to common peroneal nerve injury. The nerve is often injured because it winds around the neck of the fibula. The common peroneal nerve is responsible for dorsiflexion of the foot, and an injury to this nerve can cause foot drop, which is characterized by a high stepping gait. In foot drop, the foot appears floppy, and the toes point downward, scraping the ground while walking. The patient tends to lift their foot very high to avoid dragging it on the ground. Eversion of the foot is not the correct answer, as it is controlled by the superficial peroneal nerve. Flexion of toes is also an incorrect answer, as it is controlled by the medial plantar nerve.

Lower limb anatomy is an important topic that often appears in examinations. One aspect of this topic is the nerves that control motor and sensory functions in the lower limb. The femoral nerve controls knee extension and thigh flexion, and provides sensation to the anterior and medial aspect of the thigh and lower leg. It is commonly injured in cases of hip and pelvic fractures, as well as stab or gunshot wounds. The obturator nerve controls thigh adduction and provides sensation to the medial thigh. It can be injured in cases of anterior hip dislocation. The lateral cutaneous nerve of the thigh provides sensory function to the lateral and posterior surfaces of the thigh, and can be compressed near the ASIS, resulting in a condition called meralgia paraesthetica. The tibial nerve controls foot plantarflexion and inversion, and provides sensation to the sole of the foot. It is not commonly injured as it is deep and well protected, but can be affected by popliteal lacerations or posterior knee dislocation. The common peroneal nerve controls foot dorsiflexion and eversion, and can be injured at the neck of the fibula, resulting in foot drop. The superior gluteal nerve controls hip abduction and can be injured in cases of misplaced intramuscular injection, hip surgery, pelvic fracture, or posterior hip dislocation. Injury to this nerve can result in a positive Trendelenburg sign. The inferior gluteal nerve controls hip extension and lateral rotation, and is generally injured in association with the sciatic nerve. Injury to this nerve can result in difficulty rising from a seated position, as well as difficulty jumping or climbing stairs.

Sulfasalazine: A DMARD for Inflammatory Arthritis and Bowel Disease

Sulfasalazine is a type of disease modifying anti-rheumatic drug (DMARD) that is commonly used to manage inflammatory arthritis, particularly rheumatoid arthritis, as well as inflammatory bowel disease. This medication is a prodrug for 5-ASA, which works by reducing neutrophil chemotaxis and suppressing the proliferation of lymphocytes and pro-inflammatory cytokines.

However, caution should be taken when using sulfasalazine in patients with G6PD deficiency or those who are allergic to aspirin or sulphonamides due to the risk of cross-sensitivity. Adverse effects of sulfasalazine may include oligospermia, Stevens-Johnson syndrome, pneumonitis/lung fibrosis, myelosuppression, Heinz body anaemia, megaloblastic anaemia, and the potential to color tears and stain contact lenses.

Despite these potential side effects, sulfasalazine is considered safe to use during pregnancy and breastfeeding, making it a viable option for women who require treatment for inflammatory arthritis or bowel disease.

Rheumatoid arthritis is more prevalent in female patients, with a 3-fold higher incidence compared to males. It is characterized by symmetrical pain and stiffness, particularly in the morning. Rheumatoid arthritis can affect individuals of any age and is treated with medications such as prednisolone. Contrary to popular belief, gout does not increase the likelihood of developing rheumatoid arthritis. Additionally, ethnicity, specifically being of white descent, is not considered a risk factor for this condition.

Understanding the Epidemiology of Rheumatoid Arthritis

Rheumatoid arthritis is a chronic autoimmune disease that affects people of all ages, but it typically peaks between the ages of 30 and 50. The condition is more common in women, with a female-to-male ratio of 3:1. The prevalence of rheumatoid arthritis is estimated to be around 1% of the population. However, there are some ethnic differences in the incidence of the disease, with Native Americans having a higher prevalence than other groups.

Researchers have identified a genetic link to rheumatoid arthritis, with the HLA-DR4 gene being associated with the development of the condition. This gene is particularly linked to a subtype of rheumatoid arthritis known as Felty’s syndrome. Understanding the epidemiology of rheumatoid arthritis is important for healthcare professionals to provide appropriate care and support to those affected by the disease. By identifying risk factors and understanding the prevalence of the condition, healthcare providers can better tailor their treatment plans to meet the needs of their patients.

Peptic ulcers can be caused by the use of NSAIDs as a medication. Symptoms of peptic ulcer disease include a burning pain in the chest, which may be accompanied by belching, alcohol consumption, and high-fat foods. However, it is important to rule out any cardiac causes of the pain, especially in patients with a medical history of high cholesterol and type two diabetes.

Other medications that can cause peptic ulcer disease include aspirin and corticosteroids. Each medication has its own specific side effects, such as myalgia with atorvastatin, hypoglycemia with gliclazide, abdominal pain with metformin, and bradycardia with propranolol.

Understanding Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) and COX-2 Selective NSAIDs

Non-steroidal anti-inflammatory drugs (NSAIDs) are medications that work by inhibiting the activity of cyclooxygenase enzymes, which are responsible for producing key mediators involved in inflammation such as prostaglandins. By reducing the production of these mediators, NSAIDs can help alleviate pain and reduce inflammation. Examples of NSAIDs include ibuprofen, diclofenac, naproxen, and aspirin.

However, NSAIDs can also have important and common side-effects, such as peptic ulceration and exacerbation of asthma. To address these concerns, COX-2 selective NSAIDs were developed. These medications were designed to reduce the incidence of side-effects seen with traditional NSAIDs, particularly peptic ulceration. Examples of COX-2 selective NSAIDs include celecoxib and etoricoxib.

Despite their potential benefits, COX-2 selective NSAIDs are not widely used due to ongoing concerns about cardiovascular safety. This led to the withdrawal of rofecoxib (‘Vioxx’) in 2004. As with any medication, it is important to discuss the potential risks and benefits of NSAIDs and COX-2 selective NSAIDs with a healthcare provider before use.

The distal fibula is located in front of the sural nerve. Subtalar movements involve inversion and eversion. When passing behind the medial malleolus from front to back, the structures include the tibialis posterior, flexor digitorum longus, posterior tibial vein, posterior tibial artery, nerve, and flexor hallucis longus.

Anatomy of the Ankle Joint

The ankle joint is a type of synovial joint that is made up of the tibia and fibula superiorly and the talus inferiorly. It is supported by several ligaments, including the deltoid ligament, lateral collateral ligament, and talofibular ligaments. The calcaneofibular ligament is separate from the fibrous capsule of the joint, while the two talofibular ligaments are fused with it. The syndesmosis is composed of the antero-inferior tibiofibular ligament, postero-inferior tibiofibular ligament, inferior transverse tibiofibular ligament, and interosseous ligament.

The ankle joint allows for plantar flexion and dorsiflexion movements, with a range of 55 and 35 degrees, respectively. Inversion and eversion movements occur at the level of the sub talar joint. The ankle joint is innervated by branches of the deep peroneal and tibial nerves.

Reference:
Golano P et al. Anatomy of the ankle ligaments: a pictorial essay. Knee Surg Sports Traumatol Arthrosc. 2010 May;18(5):557-69.

Understanding Pellagra: Symptoms and Causes

Pellagra is a condition that results from a deficiency of nicotinic acid, also known as niacin. The classic symptoms of pellagra are commonly referred to as the 3 D’s: dermatitis, diarrhoea, and dementia. Dermatitis is characterized by a scaly, brown rash that appears on sun-exposed areas of the skin, often forming a necklace-like pattern around the neck known as Casal’s necklace. Diarrhoea and dementia are also common symptoms of pellagra, with patients experiencing chronic diarrhoea and cognitive impairment, including depression and confusion.

Pellagra can occur as a result of isoniazid therapy, which inhibits the conversion of tryptophan to niacin. This condition is also more common in individuals who consume excessive amounts of alcohol. If left untreated, pellagra can be fatal. Therefore, it is important to recognize the symptoms and seek medical attention promptly. With proper treatment, including niacin supplementation and dietary changes, individuals with pellagra can recover and avoid further complications.

If surgery requires the division of the strap muscles, it is recommended to divide them in their upper half as their nerve supply from the ansa cervicalis enters in their lower half.

The Anterior Triangle of the Neck: Boundaries and Contents

The anterior triangle of the neck is a region that is bounded by the anterior border of the sternocleidomastoid muscle, the lower border of the mandible, and the anterior midline. It is further divided into three sub-triangles by the digastric muscle and the omohyoid muscle. The muscular triangle contains the neck strap muscles, while the carotid triangle contains the carotid sheath, which houses the common carotid artery, the vagus nerve, and the internal jugular vein. The submandibular triangle, located below the digastric muscle, contains the submandibular gland, submandibular nodes, facial vessels, hypoglossal nerve, and other structures.

The digastric muscle, which separates the submandibular triangle from the muscular triangle, is innervated by two different nerves. The anterior belly of the digastric muscle is supplied by the mylohyoid nerve, while the posterior belly is supplied by the facial nerve.

Overall, the anterior triangle of the neck is an important anatomical region that contains many vital structures, including blood vessels, nerves, and glands. Understanding the boundaries and contents of this region is essential for medical professionals who work in this area.

Fractures in the neck of the femur can be extremely dangerous, especially in elderly women with osteoporosis who experience minor trauma. However, they can also be caused by a single traumatic event.

When the femoral neck is fractured, the femur is displaced anteriorly and superiorly, resulting in a shortened leg. This displacement causes the medial rotators to become lax and the lateral rotators to become taut, leading to lateral rotation of the leg.

The blood supply to the femoral neck is delicate and is provided by the lateral and medial circumflex femoral arteries, which give off reticular arteries that pierce the joint capsule. These arteries are branches of the femoral artery.

The hip joint is supplied by two anastomoses: the trochanteric anastomosis, formed by the circumflex femoral arteries and the descending branch of the superior gluteal, and the Cruciate anastomosis, formed by the circumflex femoral, descending branch of the inferior gluteal, and ascending branch of the first perforating artery.

The femoral head has a high metabolic rate due to its wide range of movement, which stimulates bone turnover and remodeling. This requires an adequate blood supply.

Intracapsular fractures in the cervical or subcapital regions can impede blood supply and lead to avascular necrosis of the head. However, intertrochanteric fractures spare the blood supply.

Hip fractures are a common occurrence, particularly in elderly women with osteoporosis. The femoral head’s blood supply runs up the neck, making avascular necrosis a risk in displaced fractures. Symptoms include pain and a shortened and externally rotated leg. Patients with non-displaced or incomplete neck of femur fractures may still be able to bear weight. Hip fractures are classified based on their location, either intracapsular or extracapsular. The Garden system is a commonly used classification system that categorizes fractures into four types based on stability and displacement. Blood supply disruption is most common in Types III and IV.

Undisplaced intracapsular fractures can be treated with internal fixation or hemiarthroplasty if the patient is unfit. Displaced fractures require replacement arthroplasty, with total hip replacement being preferred over hemiarthroplasty if the patient was able to walk independently outdoors with no more than a stick, is not cognitively impaired, and is medically fit for anesthesia and the procedure. Extracapsular fractures are managed with a dynamic hip screw for stable intertrochanteric fractures and an intramedullary device for reverse oblique, transverse, or subtrochanteric fractures.

The fibular head serves as the insertion point for both the long and short head of the biceps femoris muscle. However, sudden contractions of the biceps femoris can lead to an avulsion fracture of the fibular head, where the fracture fragment may be attached to the lateral collateral ligament or biceps femoris tendon.

The fibularis brevis muscle originates from the distal two-thirds of the fibular bone. If the ankle joint suddenly inverts, it can pull on the fibularis tendon and cause an avulsion of the tuberosity at the base of the fifth metatarsal.

The flexor hallucis longus muscle originates from the distal two-thirds of the posterior surface of the fibular bone. This muscle not only allows for flexion of the big toe but also contributes to plantarflexion and inversion of the foot.

The soleus muscle originates from the proximal one-third of the posterior surface of the fibular bone. It is a large muscle covered in thick fascia, which aids in its secondary function of pumping venous blood back into the heart through the skeletal muscle pump.

The Biceps Femoris Muscle

The biceps femoris is a muscle located in the posterior upper thigh and is part of the hamstring group of muscles. It consists of two heads: the long head and the short head. The long head originates from the ischial tuberosity and inserts into the fibular head. Its actions include knee flexion, lateral rotation of the tibia, and extension of the hip. It is innervated by the tibial division of the sciatic nerve and supplied by the profunda femoris artery, inferior gluteal artery, and the superior muscular branches of the popliteal artery.

On the other hand, the short head originates from the lateral lip of the linea aspera and the lateral supracondylar ridge of the femur. It also inserts into the fibular head and is responsible for knee flexion and lateral rotation of the tibia. It is innervated by the common peroneal division of the sciatic nerve and supplied by the same arteries as the long head.

Understanding the anatomy and function of the biceps femoris muscle is important in the diagnosis and treatment of injuries and conditions affecting the posterior thigh.

Pemphigus vulgaris is an autoimmune condition that occurs when the body’s immune system attacks desmoglein 3, a type of cell adhesion molecule found in epithelial cells. This disease is more prevalent in the Ashkenazi Jewish population. The most common symptom is mucosal ulceration, which can be the first sign of the disease. Oral involvement is seen in 50-70% of patients. Skin blistering is also a common symptom, with easily ruptured vesicles and bullae. These lesions are typically painful but not itchy and may appear months after the initial mucosal symptoms. Nikolsky’s sign is a characteristic feature of pemphigus vulgaris, where bullae spread following the application of horizontal, tangential pressure to the skin. Biopsy results often show acantholysis.

The first-line treatment for pemphigus vulgaris is steroids, which help to reduce inflammation and suppress the immune system. Immunosuppressants may also be used to manage the disease.

The most likely diagnosis based on the history and examination is impetigo or eczema herpeticum, which can have similar presentations and are difficult to differentiate clinically. However, since the child has no prior history of skin conditions, eczema herpeticum is less probable. Therefore, option 2 is the correct answer.

Option 1: Atopic eczema would not manifest with a yellowish crust.

Option 3: Chickenpox would not exhibit this particular progression.

Understanding Impetigo: Causes, Symptoms, and Management

Impetigo is a common bacterial skin infection that is caused by either Staphylococcus aureus or Streptococcus pyogenes. It can occur as a primary infection or as a complication of an existing skin condition such as eczema. Impetigo is most common in children, especially during warm weather. The infection can develop anywhere on the body, but it tends to occur on the face, flexures, and limbs not covered by clothing.

The infection spreads through direct contact with discharges from the scabs of an infected person. The bacteria invade the skin through minor abrasions and then spread to other sites by scratching. Infection is spread mainly by the hands, but indirect spread via toys, clothing, equipment, and the environment may occur. The incubation period is between 4 to 10 days.

Symptoms of impetigo include ‘golden’, crusted skin lesions typically found around the mouth. It is highly contagious, and children should be excluded from school until the lesions are crusted and healed or 48 hours after commencing antibiotic treatment.

Management of impetigo depends on the extent of the disease. Limited, localized disease can be treated with hydrogen peroxide 1% cream or topical antibiotic creams such as fusidic acid or mupirocin. MRSA is not susceptible to either fusidic acid or retapamulin, so topical mupirocin should be used in this situation. Extensive disease may require oral flucloxacillin or oral erythromycin if penicillin-allergic. The use of hydrogen peroxide 1% cream was recommended by NICE and Public Health England in 2020 to cut antibiotic resistance. The evidence base shows it is just as effective at treating non-bullous impetigo as a topical antibiotic.

The forearm has two weight-bearing bones, the scaphoid at the wrist and the radius within the forearm. If someone falls onto outstretched hands, there is a risk of fracturing both of these bones. The shaft of the radius is particularly vulnerable as it carries the weight and takes the full compression of the fall. The ulna is more likely to fracture from stress applied to the side of the arm rather than down its length. The lunate bone at the wrist is not involved in weight-bearing.

Anatomy of the Radius Bone

The radius bone is one of the two long bones in the forearm that extends from the lateral side of the elbow to the thumb side of the wrist. It has two expanded ends, with the distal end being the larger one. The upper end of the radius bone has articular cartilage that covers the medial to lateral side and articulates with the radial notch of the ulna by the annular ligament. The biceps brachii muscle attaches to the tuberosity of the upper end.

The shaft of the radius bone has several muscle attachments. The upper third of the body has the supinator, flexor digitorum superficialis, and flexor pollicis longus muscles. The middle third of the body has the pronator teres muscle, while the lower quarter of the body has the pronator quadratus muscle and the tendon of supinator longus.

The lower end of the radius bone is quadrilateral in shape. The anterior surface is covered by the capsule of the wrist joint, while the medial surface has the head of the ulna. The lateral surface ends in the styloid process, and the posterior surface has three grooves that contain the tendons of extensor carpi radialis longus and brevis, extensor pollicis longus, and extensor indicis. Understanding the anatomy of the radius bone is crucial in diagnosing and treating injuries and conditions that affect this bone.

Bisphosphonates, such as alendronate and risedronate, are used to treat osteoporosis by preventing bone resorption through the inhibition of osteoclasts. These drugs are taken up by the osteoclasts, preventing them from adhering to the bone surface and continuing the resorption process.

Denosumab is a monoclonal antibody that works by binding to the receptor activator of nuclear factor kappa-B ligand (RANK-L), which blocks the interaction between RANK-L and RANK, ultimately reducing bone resorption.

Raloxifene is a selective estrogen receptor modulator that has estrogen-like effects on bone, leading to decreased bone resorption and improved bone density.

Romosozumab is a monoclonal antibody that inhibits the action of sclerostin, a regulatory factor in bone metabolism, ultimately leading to increased bone formation.

Bisphosphonates: Uses, Adverse Effects, and Patient Counselling

Bisphosphonates are drugs that mimic the action of pyrophosphate, a molecule that helps prevent bone demineralization. They work by inhibiting osteoclasts, the cells responsible for breaking down bone tissue. Bisphosphonates are commonly used to prevent and treat osteoporosis, hypercalcemia, Paget’s disease, and pain from bone metastases.

However, bisphosphonates can cause adverse effects such as oesophageal reactions, osteonecrosis of the jaw, and an increased risk of atypical stress fractures of the proximal femoral shaft in patients taking alendronate. Patients may also experience an acute phase response, which includes fever, myalgia, and arthralgia following administration. Hypocalcemia may also occur due to reduced calcium efflux from bone, but this is usually clinically unimportant.

To minimize the risk of adverse effects, patients taking oral bisphosphonates should swallow the tablets whole with plenty of water while sitting or standing. They should take the medication on an empty stomach at least 30 minutes before breakfast or another oral medication and remain upright for at least 30 minutes after taking the tablet. Hypocalcemia and vitamin D deficiency should be corrected before starting bisphosphonate treatment. However, calcium supplements should only be prescribed if dietary intake is inadequate when starting bisphosphonate treatment for osteoporosis. Vitamin D supplements are usually given.

The duration of bisphosphonate treatment varies depending on the level of risk. Some experts recommend stopping bisphosphonates after five years if the patient is under 75 years old, has a femoral neck T-score of more than -2.5, and is at low risk according to FRAX/NOGG.

Guttate psoriasis is frequently seen after a streptococcal infection, with group-A streptococcus being the likely culprit. The condition is characterized by the appearance of small, teardrop shaped red lesions. Scarlet fever, which is also caused by group-A streptococcus, presents with a rough rash, fever, swollen lymph nodes, and a red tongue. Pityriasis rosea, on the other hand, typically follows a viral infection and is identified by a single scaly patch followed by a widespread salmon-pink rash. Acne vulgaris and impetigo are not commonly associated with a streptococcal sore throat.

Guttate psoriasis is a type of psoriasis that is more commonly seen in children and adolescents. It is often triggered by a streptococcal infection that occurred 2-4 weeks prior to the appearance of the lesions. The condition is characterized by the presence of tear drop-shaped papules on the trunk and limbs, along with pink, scaly patches or plaques of psoriasis. The onset of guttate psoriasis tends to be acute, occurring over a few days.

In most cases, guttate psoriasis resolves on its own within 2-3 months. There is no clear evidence to support the use of antibiotics to treat streptococcal infections associated with the condition. Treatment options for guttate psoriasis include topical agents commonly used for psoriasis and UVB phototherapy. In cases where the condition recurs, a tonsillectomy may be necessary.

It is important to differentiate guttate psoriasis from pityriasis rosea, which is another skin condition that can present with similar symptoms. Guttate psoriasis is typically preceded by a streptococcal sore throat, while pityriasis rosea may be associated with recent respiratory tract infections. The appearance of guttate psoriasis is characterized by tear drop-shaped, scaly papules on the trunk and limbs, while pityriasis rosea presents with a herald patch followed by multiple erythematous, slightly raised oval lesions with a fine scale. Pityriasis rosea is self-limiting and resolves after around 6 weeks.

The cubital fossa contains the following structures in order from lateral to medial: radial nerve, brachial tendon, brachial artery, and median nerve. In this case, the damaged nerve is the median nerve, which is located most medially in the cubital fossa, next to the brachial artery.

In the antecubital fossa, the radial nerve is located deep and laterally, next to the biceps tendon. The biceps tendon serves as a marker for finding the brachial artery, which is located medially to it.

It is incorrect to say that there is a nerve located between the biceps tendon and the brachial artery in the antecubital fossa.

The Antecubital Fossa: Anatomy and Clinical Significance

The antecubital fossa is a depression located on the anterior aspect of the arm, between the arm and forearm. It is an important area for medical professionals as it is where venous blood samples are typically taken from. The borders of the antecubital fossa are the brachioradialis muscle laterally, the pronator teres medially, and a line between the medial and lateral epicondyles superiorly.

There are both deep and superficial structures found in the antecubital fossa. Deep structures include the radial nerve, tendon of the biceps muscle, brachial artery, and medial nerve. Superficial structures consist of a network of veins, including the cephalic vein and basilic vein, which come together as the median cubital vein.

The main clinical relevance of the antecubital fossa is its use for blood sampling and cannulation. However, it is also important to have a working knowledge of the anatomy as structures can become damaged. Excessive straining of the biceps tendon can cause it to rupture, leading to a ‘Popeye sign’. Damage to the medial nerve can also occur, resulting in muscle paralysis in the forearm and hand. Overall, understanding the anatomy and clinical significance of the antecubital fossa is crucial for medical professionals.

Chlorphenamine is a medication.

Antihistamines for Allergic Rhinitis and Urticaria

Antihistamines, specifically H1 inhibitors, are effective in treating allergic rhinitis and urticaria. Sedating antihistamines like chlorpheniramine have antimuscarinic properties that can cause dry mouth and urinary retention. On the other hand, non-sedating antihistamines like loratadine and cetirizine are less likely to cause drowsiness. However, there is some evidence that cetirizine may still cause some level of drowsiness compared to other non-sedating antihistamines. Overall, antihistamines are a valuable treatment option for those suffering from allergic rhinitis and urticaria.

Mycophenolate mofetil (MMF) is an immunosuppressant that inhibits inosine-5′-monophosphate dehydrogenase, an enzyme necessary for purine synthesis. MMF is commonly used in organ transplantation and autoimmune disorders. Azathioprine also inhibits purine synthesis, but through a different mechanism.

Calcineurin inhibitors, such as tacrolimus and ciclosporin, reduce T-cell differentiation to suppress the immune system.

Protease inhibitors, like ritonavir and darunavir, are antivirals used to treat HIV and hepatitis.

HMG-CoA reductase inhibitors, such as statins, lower LDL cholesterol levels.

Hydroxycarbamide is a ribonucleotide reductase inhibitor that reduces the production of deoxyribonucleotides, thereby decreasing DNA synthesis. It is used to treat cancer.

Mycophenolate Mofetil: How it Works as an Immunosuppressant

Mycophenolate mofetil is a medication that is often prescribed to prevent the rejection of organ transplants. It works by inhibiting the activity of inosine monophosphate dehydrogenase, an enzyme that is necessary for the synthesis of purines. Since T and B cells rely heavily on this pathway for their proliferation, mycophenolate mofetil can effectively reduce the activity of these immune cells.

In simpler terms, mycophenolate mofetil works by blocking a key enzyme that immune cells need to grow and multiply. By doing so, it can help prevent the body from attacking and rejecting a transplanted organ. This medication is often used in combination with other immunosuppressants to achieve the best possible outcomes for transplant patients.

Trapezius is not related to the mnemonic for the carpal bones.

Carpal Bones: The Wrist’s Building Blocks

The wrist is composed of eight carpal bones, which are arranged in two rows of four. These bones are convex from side to side posteriorly and concave anteriorly. The trapezium is located at the base of the first metacarpal bone, which is the base of the thumb. The scaphoid, lunate, and triquetrum bones do not have any tendons attached to them, but they are stabilized by ligaments.

In summary, the carpal bones are the building blocks of the wrist, and they play a crucial role in the wrist’s movement and stability. The trapezium bone is located at the base of the thumb, while the scaphoid, lunate, and triquetrum bones are stabilized by ligaments. Understanding the anatomy of the wrist is essential for diagnosing and treating wrist injuries and conditions.

The posterior tibial artery is responsible for supplying oxygenated blood to the posterior compartment of the leg as well as the plantar surface of the foot.

Anatomy of the Posterior Tibial Artery

The posterior tibial artery is a major branch of the popliteal artery that terminates by dividing into the medial and lateral plantar arteries. It is accompanied by two veins throughout its length and its position corresponds to a line drawn from the lower angle of the popliteal fossa to a point midway between the medial malleolus and the most prominent part of the heel.

The artery is located anteriorly to the tibialis posterior and flexor digitorum longus muscles, and posteriorly to the surface of the tibia and ankle joint. The posterior tibial nerve is located 2.5 cm distal to its origin. The proximal part of the artery is covered by the gastrocnemius and soleus muscles, while the distal part is covered by skin and fascia. The artery is also covered by the fascia overlying the deep muscular layer.

Understanding the anatomy of the posterior tibial artery is important for medical professionals, as it plays a crucial role in the blood supply to the foot and ankle. Any damage or blockage to this artery can lead to serious complications, such as peripheral artery disease or even amputation.

Dupuytren’s contracture commonly affects the ring finger and little finger, particularly in older males. This condition causes nodules and cord development in the palmar fascia, resulting in flexion at the metacarpophalangeal and proximal interphalangeal joints.

Trigger finger causes stiffness, pain, and a locking sensation when flexing, making it difficult to extend the finger.

Ganglion cysts, also known as bible cysts, are typically soft and found in the dorsal and volar aspect of the wrist. Many cysts will disappear on their own.

Flexor tendon rupture is usually caused by trauma to the flexor tendon, such as a sports injury. This condition is typically acute and results in a sudden loss of flexion in the affected finger, often requiring surgery.

Understanding Dupuytren’s Contracture

Dupuytren’s contracture is a condition that affects about 5% of the population. It is more common in older men and those with a family history of the condition. The causes of Dupuytren’s contracture include manual labor, phenytoin treatment, alcoholic liver disease, diabetes mellitus, and trauma to the hand.

The condition typically affects the ring finger and little finger, causing them to become bent and difficult to straighten. In severe cases, the hand may not be able to be placed flat on a table.

Surgical treatment may be necessary when the metacarpophalangeal joints cannot be straightened.

Understanding Ulnar Nerve Injury at the Wrist

The ulnar nerve is a major nerve that runs from the neck down to the hand. At the wrist, it divides into two branches: the superficial and deep branches. The superficial branch provides sensation to the skin of the medial third of the palm and one and a half fingers. Meanwhile, the deep branch supplies the abductor and short flexor of the little finger, as well as the opponens digiti minimi. It also passes over the Hook of the Hamate bone and ends in the first dorsal interosseous muscle. In the palm, the deep branch innervates the lumbricals and interosseous muscles.

Ulnar nerve injury at the wrist can occur due to various reasons, such as trauma, compression, or repetitive strain. Symptoms may include numbness, tingling, weakness, and pain in the affected area. Treatment options depend on the severity of the injury and may include rest, physical therapy, medication, or surgery.