Physikalische Urtikaria: Klinik, Diagnostik und Therapie

Abstract

Summary Physical urticaria: clinical findings, diagnosis and therapy Physical urticaria is defined as a type of urticaria triggered by physical stimuli. It accounts for some 15–20% of all urticaria cases.Mechanical stimuli provoke dermographism, pressure urticaria and vibra-tory angiooedema. Thermal stimuli induce cold and heat urticaria. Electromag-netic waves may trigger solar urticaria. Raising of the body core temperaturecauses cholinergic urticaria. Urticaria factitia, which can be elicited by dermographism, represents themost frequent form of urticaria, with an incidence of 7–9%. Urticaria factitiais also frequently associated with chronic idiopathic urticaria. If IgE in the serum of urticaria patients is passively transferred to healthyvolunteers by the so-called Prausnitz-Kustner test, the relevant mechanicalstimuli may also induce hives in the serum recipient. Such passive transfer of “hypersensitivity” to physical stimuli is observedin up to 69% of patients with urticaria factitia and in about a third with coldurticaria. It may also be observed in patients with light urticaria to UVB at awavelength of 400–500 nm. Delayed pressure urticaria is characterised histologically by an inflamma-tory infiltrate consisting of eosinophils, neutrophils and moderate vasculitis.Delayed pressure urticaria alone represents less than 1% of all urticariacauses. Delayed pressure urticaria is more frequently associated with chronicurticaria similar to urticaria factitia, and follows a prolonged course spanningyears. Cold urticaria is provoked by cooling of the skin or body core temperatureand does not necessarily depend on the absolute temperatures. Some 95% ofall cold urticaria cases are idiopathic. The other forms are associated with infection (syphilis, borreliosis, measles, varicella, hepatitis, mononucleosis,HIV) and with neoplasms or autoimmune diseases.