The skin of individuals with rosacea has a greater sensitivity to heat, according to a recent study in the Journal of the American Academy of Dermatology. Patients with rosacea "often complain of increased skin sensitivity and frequently describe a burning sensation," said Dr. Daniela Guzman-Sanchez and colleagues of the Wake Forest University School of Medicine. They noted that although this heightened sensitivity is well recognized in practice, there had been no formal research on the phenomenon. In their study of 24 individuals, 16 had rosacea, half with subtype 1 (erythematotelangiectatic) rosacea, characterized by redness and flushing, and half with subtype 2 (papulopustular) rosacea, characterized by bumps and pimples. The remaining eight individuals served as a control group without rosacea. All of the study subjects were exposed to a device that warmed the skin of the cheek beginning at almost 90 degrees Fahrenheit, with a potential high of about 122 degrees. Individuals were asked to rate their perception of burning, and skin blood flow and skin temperature were also measured. The researches found that individuals with both subtypes of rosacea had a significantly greater sensitivity to heat pain on symptomatic skin, compared to skin without symptoms and to the skin of individuals without rosacea. Moreover, when patients rated pain themselves, there was a significantly greater perception of pain in the subtype 1 group with flushing than in those with subtype 2 rosacea. Skin blood flow was significantly higher in areas with bumps and pimples than in normal skin, and there was a high correlation between skin temperature and skin blood flow in all three groups. The researchers pointed out that while 15 of the 16 rosacea patients reported burning, none reported itching, and thus it is possible that the increased skin sensitivity explains the common complaint of burning sensation in rosacea. They noted that, although they found no correlation between blood flow and burning perception, future research on the effect of vasodilators such as alcohol and heat on blood flow and heat pain thresholds may be especially valuable. Reference Guzman-Sanchez D, Ishiuji Y, Patel T, Fountain J, Chan YH, Yosipovitch G. Enhanced skin blood flow and sensitivity to noxious heat stimuli in papulopustular rosacea. Journal of the American Academy of Dermatology 2007;57:800-805.