ABSTRACT
The physical urticarias are a distinct subgroup of urticarias in which a specific physical stimulus induces reproducible whealing (1-3). They are classified according to the eliciting stimulus (4,5) (Table I) Cholinergic urticaria occurs in response to stimulation of sweating such as caused by general overheating compared to local heat application. Although it is not strictly a physical urticaria, because it also may be triggered by stimulation of emotional and gustatory sweating, it is frequently included in the physical urticaria group for convenience. Aquagenic and adrenergic urticaria, which morphologically resemble cholinergic urtiaria, are also included.
