Oral thermal-induced flushing in erythematotelangiectatic rosacea.

The effects of caffeine and coffee, agents widely alleged to provoke flushing in patients with erythematotelangiectatic rosacea, were investigated. Neither caffeine nor coffee at 22 degrees C led to flushing reactions. Both coffee at 60 degrees C and water at 60 degrees C led to flushing reactions with similar temporal characteristics and of similar intensities. It is concluded that the active agent causing flushing in coffee at 60 degrees C is heat, not caffeine.