Hot or spicy foods, febrile illnesses, and hot baths may also initiate attacks. Heating of the skin or exercise sufficient to raise the body temperature 0.5☌ will induce attacks of multiple wheals with itching. 1, 7, 8 It occurs in up to 3% of adolescents. Heat- and exercise-induced urticaria: Heat- and exercise-induced urticaria (cholinergic urticaria) is characterized by a large (10–20 mm), blotchy erythema surrounding tiny (1–3 mm) central wheals ( Figs 14.10, 14.11). Dermatographism may persist for years, but most patients can expect spontaneous regression within 2 years. Dermatographism is also seen in about half of children with mastocytosis. in encephalitis, meningitis, drug overdose) and has been termed tache cérébrale. The wheal is seen in comatose children (e.g. Wheals are commonly found around the belt area and may follow widespread insect bites and transient episodes of urticaria. The wheal reaches maximal size in 6–7 minutes and persists for 10–15 minutes.
1, 7, 8, 18–28 Clinical featuresĭermatographism: Dermatographism occurs in 1% of adolescents and is characterized by wheal and erythema after minor stroking of or pressure on the skin ( Figs 14.8, 14.9), 1, 7, 8 often results in mild itching. The physical urticarias, which account for 15% of this group, consist of dermatographism, heat- and exercise-induced urticaria, delayed-pressure urticaria, cold urticaria, and familial cold urticaria. Urticaria that persists for over 4 weeks may be simply prolonged common urticaria or may be caused by one of the physical urticarias, urticarial vasculitis, or mastocytosis.
Morelli MD, in Color Textbook of Pediatric Dermatology (Fourth Edition), 2007 The physical urticarias
0 kommentar(er)
