Cholinergic urticaria: novel aspects of pathogenesis, diagnosis and management

Cholinergic urticaria (CholU) is a chronic inducible urticaria, characterised by itchy pinpoint wheals up to 3 mm in diameter, surrounded by a prominent flare, that occur following an exposure to characteristic triggers such as active or passive heating, physical exercise, emotions, hot or spicy foods. Key pathophysiologic mechanisms include immediate hypersensitivity to autologous sweat antigens, functional sweating disorders, impaired acethylcholine metabolism, abnormal skin vascular permeability and disturbed skin innervation. Clinical manifestations of CholU may vary from typical itchy pinpoint urticarial lesions, angioedema to anaphylaxis. Atypical CholU forms include cholinergic pruritus, cholinergic dermographism, cold cholinergic urticaria and persistent cholinergic erythema. The diagnosis of cholinergic urticaria relies on patients history, сlinical manifestations and challenge tests. Treatment options include nonsedating H1 antihistamines in standard or increased doses. The evidence is accumulating for the use of biological treatment with omalizumab in cholinergic urticaria. The prospect of personalized treatment of cholinergic urticaria include autologous sweat desensitization. The main research efforts in ColdU are directed at optimizing diagnostic approaches and developing innovative therapeutic options.