Photodermatoses—idiopathic Polymorphic light eruption Polymorphic light eruption is often incorrectly referred to as ‘prickly heat’ (a different condition) and is characterized by pruritic papules, plaques and sometimes vesicles that last for days in light-exposed areas. Clinical presentation This is the…
Definition Erythroderma or generalized exfoliative dermatitis defines any inflammatory dermatosis that involves all or nearly all the skin surface (sometimes stated as more than 90%). It is a secondary process and represents the generalized spread of a dermatosis or systemic…
Papulosquamous eruptions are raised, scaly and marginated, and include psoriasis, lichen planus and other conditions listed in Box 24.1 . Eczema is not included as it does not usually have a sharp edge. These eruptions are not related aetiologically. Several…
Lichen planus and other disorders with a lichenoid appearance of shiny flat-topped papules are presented here. Lichen planus Lichen planus is a relatively common pruritic papular dermatosis involving the flexor surfaces, mucous membrane and genitalia. The cause is unknown, but…
The other main types of dermatitis are seborrhoeic, hand, pompholyx, discoid, venous, and asteatotic eczema. Seborrhoeic dermatitis Seborrhoeic dermatitis is a scaly eruption, usually affecting the scalp and eyebrows. Other patterns are recognized. The condition is usually less itchy than…
Definition Atopic eczema is predominantly a disease of childhood that gives rise to poorly demarcated chronic pruritic papular inflammation of the skin. Uncontrollable scratching is prominent. Most cases improve with age, although approximately 50% of children retain evidence of the…
Definition Allergic contact dermatitis is an eczema precipitated by an exogenous agent, often a chemical, which is recognized by the immune system as an antigen and results in T-cell-mediated inflammation. Often, irritant and endogenous factors are also involved in the…
Definition Eczema is a non-infective inflammatory skin condition that shows itching, redness, papulation and scaling. Eczema represents a reaction pattern to a variety of stimuli, some of which are recognized but many of which are unknown. Eczema and dermatitis mean…
Research has confirmed psoriasis to be an immune-mediated inflammatory disease, with associated genes involved in immune regulation ( Fig. 18.1 ). These recent discoveries have allowed the pharmaceutical industry to specifically design biologic drugs that work in psoriasis and in…
Planning treatment The non-infectious nature of psoriasis, its relapsing nature and the likely need for long-term therapy should be explained. A sympathetic approach is helpful, and patients often obtain support from the self-help group the Psoriasis Association. Treatment is tailored…