A patient gets reccurent urticaria while doing exercise and on exposure to sunligh. Which of the following is most like cause –: (A) Chronic Idiopathic Utricaria, (B) Universal dermographism, (C) Cholinergic utricaria, (D) photodermatitis
Answer is C. This patient develops urticaria after:-


Exercise
Exposure to sunlight → generalized heating


Both of these provoke cholinergic urticaria due to stimulation of cholinergic sympathetic fibres.