Skin diseases and allergic reactions 

It is an inherited inflammatory condition of the skin

It is an acute and often life-threatening immunologic reaction, frequently heralded by scalp pruritus, diffuse erythema, urticaria, or angioedema. Bronchospasm, laryngealedema, hyperperistalsis, hypotension, and cardiac arrhythmia may occur. Antiobitics (especially penicillins), other drugs, and radiographic contrast agents are the most common causes of serious anaphylactic reactions.

It is a dermatitis/Eczema on a background of atopy. Hence there is often a personal or family history of atopic disease (asthma, hay fever or atopic dermatitis).

Is a delayed hypersensitivity reaction following skin coming into contact with a particular chemical. This may be a dye, perfume, rubber, nickel, drugs, skin preparations containing lanolin, iodine, antihistamines, neomycin etc

A complication of shingles (herpes zoster) whereby nerve fibers and the skin is affected