Fever from caffeine

Since childhood, a 53‐year‐old women had developed chills, high‐grade fever, myalgia, and cephalea after the ingestion of coffee, tea, cola beverages, and some oral “antiflu” compounds. Skin prick tests performed with all the implicated substances were negative. Single‐blind oral challenges with both caffeine and theophylline were positive, reproducing exactly the same clinical symptoms and fever. Oral challenge with pentoxifylline was negative. We report a case of caffeine‐induced fever in which we have demonstrated cross‐reactivity with theophylline, but not with pentoxifylline.