Q. How quickly does a rosacea flare-up occur after contact with a trigger factor?

A. Although there are currently no data on how quickly exposure to a rosacea trigger may lead to a flare-up, the timing is likely to vary depending on the individual and nature of the trigger. You might try monitoring your individual case to see how quickly you respond to specific triggers. And remember, while a wide range of factors has been identified as potential triggers, not every trigger affects every individual.

Q. Does rosacea ever appear on the legs?

A. Rosacea on the legs would be a rarity, and a dermatologist should be relied upon for a professional diagnosis. According to the standard classification of rosacea developed by a consensus committee and review panel of 17 rosacea experts worldwide, rosacea signs and symptoms may also develop beyond the face, most commonly on the neck, chest, scalp or ears.

A National Rosacea Society survey of more than 1,600 rosacea patients found that 15 percent had experienced the disorder on the neck, 6 percent on the chest, 5 percent on the scalp and 4 percent on the ears.