Eczema and dermatitis
Dermatitis implies inflammation of the skin, and the term is often used interchangeably with eczema. Characteristic features are hot, red skin; edema in the acute stages; weeping and oozing; excoriation; secondary infection and impaired thermoregulation in severe cases.
What to learn
Classification and patterns of eczema: atopic/endogenous, pompholyx, exogenous, and discoid.
Psoriasis
Psoriasis is a chronic skin disease seen commonly as erythematous, well-demarcated, silvery-scaled plaques over extensor surfaces. It affects 2% of the population in temperate countries. Arthropathy is associated with the skin disease in 8% to10% of cases.
What to learn
Etiology and epidemiology.
Clinical and diagnostic features, and patterns of psoriasis.
Pemphigus and pemphigoid
These bullous disorders are rare but commonly crop up in exams. Both disorders are associated with autoimmune antibody deposition in the epidermis. The depth at which this occurs relates to the clinical features observed.
What to learn
Etiology and epidemiology of Pemphigus vulgaris and pemphigoid.
Clinical features of the two diseases: be able to compare and contrast them.
Erythema multiforme
An acute and self-limiting condition, erythema multiforme affects the skin and mucosal surfaces. Lesions are typically concentric rings of papules, especially on the hands, forearms, and feet. Erythema multiforme is associated with herpes simplex and mycoplasma infections, drug reactions, connective tissue disease, and neoplasia. Immune complex deposition in the skin seems to play a role. This topic commonly appears on exams.
What to learn
Etiology and associated conditions.
Clinical and diagnostic features.
Treatment, especially of Stephens-Johnson syndrome, which can be life-threatening.
Erythema nodosum
This is an acute condition characterized by painful nodules on the shins and occasionally on the thighs and arms; it is most common in adult females. There are many causes, including drugs, sarcoidosis, IBD, infection, and pregnancy; no cause will be found in 50% of cases. It is not a common condition but is a favorite exam topic because of the variety of causes.
What to learn
The causes and clinical features of erythema nodosum.
Investigations to exclude serious causes.
Treatment: usually conservative with nonsteroidal antiinflammatory drugs (NSAIDs); condition usually resolves in a few weeks.
Skin cancer
The three most important malignancies of the skin are basal cell carcinoma, squamous cell carcinoma, and malignant melanoma. All three types are associated with sun damage. Basal cell carcinoma is locally invasive, but metastasis is rare, whereas at the other end of the scale, malignant melanoma is highly aggressive, and the prognosis is poor if the melanoma is not treated early.
What to learn
Etiology, epidemiology, and risk factors for the three types of cancer.
Clinical and diagnostic features.
Staging and prognosis for malignant melanoma.
Management options: surgical excision and radiotherapy.
