Vasculitis and the reactive erythemas are characterized by inflammation within or around blood vessels. This may result from a type III hypersensitivity response, with circulating immune complexes, but other mechanisms are also possible. Vasculitis Vasculitis is a disease process usually…
The inflammatory disorders of connective tissue often affect several organs, as in systemic lupus erythematosus (LE), but they may also involve the skin alone (e.g. discoid LE). Autoantibodies are a feature of these diseases, which can thus be regarded as…
Blistering is often seen with skin disease. It is found with common dermatoses such as acute contact dermatitis, pompholyx, herpes simplex, herpes zoster and bullous impetigo, and it also occurs after insect bites, burns and friction or cold injury. The…
Urticaria (hives) is a common eruption characterized by wheals and angioedema. Wheals arise due to acute dermal oedema from extravascular leakage of plasma, whereas oedema deeper in the dermis and subcutis is known as angioedema. A classification is shown in…
Skin colour is due to a mixture of the pigments melanin (p. 8), oxyhaemoglobin (in blood) and carotene (in the stratum corneum and subcutaneous fat). Pigmentary diseases are common and particularly distressing to those with darker skin. Disorders of pigmentation…
Leg ulcers affect 1% of the adult population and account for 1% of dermatology referrals. They are twice as common in women as in men and are a major burden on the health service. Just over one-half are venous, one-tenth…
Blood vessel disorders Erythema Erythema is redness of the skin, usually due to vasodilatation ( Table 40.1 ). It may be localized, e.g. with pregnancy or liver disease (on palms), fixed drug eruption and infection (e.g. Lyme disease), or generalized,…
Congenital disease A number of usually rare congenital conditions can affect the nails. In nail – patella syndrome , the nails (and patellae) are absent or rudimentary. The nails in pachyonychia congenita are thickened and discoloured from birth. Racket nail…
Hair loss (alopecia) The division of alopecia into diffuse, localized and scarring or non-scarring helps in diagnosis ( Table 38.1 ). Hair loss from whatever cause (and also excessive hair) can result in psychological distress in both sexes. Scalp hair…
Rosacea Rosacea is a chronic inflammatory facial dermatosis characterized by erythema and pustules, often associated with flushing. The cause of rosacea is unknown. Histologically, dilated dermal blood vessels, sebaceous gland hyperplasia and an inflammatory cell infiltrate are seen. Sebum excretion…