Rosacea affects mostly Caucasians, though some other races can be affected. Rosacea affects both males and females. Females are three times more likely than males to get rosacea. Things that can cause rosacea are exposure of the face to extreme temperature, the heat of sunlight, severe sunburn, stress, anxiety, alcohol and spicy foods. Most people with rosacea have only mild redness and are never officially diagnosed or treated.