Refer to Chapter 14 for clinical features and management. It occurs at hands and feet. Diagnosis can be easily made from history e.g. wearing ill-fitting or new shoes. It is presented as well-circumscribed erythematous patches or bullae, frequently occurring at hands, penis and mouth. A characteristic feature is the recurrence of the same skin lesions at the same sites when patients are challenged by the same offending agents again.
Lesions heal with circumscribed pigmentation.
Histologically, subepidermal or epidermal blisters can occur. Basal cell degeneration and pigmentary incontinence are often seen. The common offending drugs include tetracycline, barbiturates, sulphonamides, phenolphthalein, salicylate and oxyphenbutazone. The disease is self-limiting. Avoidance of offending drug is most important.