Figure 1

Clinical, histological and dermoscopic features of chronic spontaneous urticaria (patient 1) and urticarial vasculitis (patients 2 and 3). Patient 1. 1 A: Multiple wheals on the legs of a woman with an urticarial rash. 1B: edema in papillary and upper reticular dermis and a mixed inflammatory infiltrate constituted by lymphocytes, eosinophils and occasional neutrophils (H&E, original magnification ×20). 1 C: dermoscopic well-defined network of red lines. Purpuric patches are absent. Patient 2. 2 A: persistent isolated and confluent erythemato-edematous urticarial papules and plaques located on a leg. 2B: A predominantly neutrophilic inflammatory infiltrate affecting the vascular walls and associated with blood extravasation and nuclear dust (karyorrhexis) (H&E, original magnification x40). 2 C: dermoscopic small irregular purpuric patches and red lines. Patient 3. 3 A: urticarial erythematous papules and plaques located on the trunk. 3B, 3 C: different degrees of dermoscopic blurred small purpuric patches and red lines on an erythematous background. 3D: dermoscopy of a residual, long lasting lesion disclosing a yellow/orange residual discoloration.