A Clinical Study of Piezogenic Papules in Korean Youth Seung Han Lee, M.D., Mu Hyoung Lee, M.D., Woo Young Sim, M.D., Nack In Kim, M.D., Choong Rim Haw, M.D. Department of Dermatology, College of Medicine, Kyung Hee University Seoul, Korea We investigated the prevalence, distribution, the number and size of the piezogenic papules in a student population, aged 15 to 25 years old. The results were as follows ; 1. The prevalence was 7.4%(86 cases/1167 students in total). 2. The prevalence in male was 4.6% (43/944), and that in female was 19.3%(43/223)(P<0.001). 3. The number of patients who had piezogenic papules on one foot was 48(55.8%), and those who had lesions bilaterally was 38(45.2%), Lesions of the left foot were more common than right. The medial aspect of the heel was 6 to 10 times a more common location compared to the lateral or posterior aspect(P<0.05). 4. The average number of lesions was 4.5 and there was no significant difference between male and female, and right and left foot. The number of papules on the medial aspect of the heel was 3 times more than that of the lateral, or posterior aspect(P<0.05). 5. The average size of lesions is 4㎜ in diameter(2㎜-10㎜), and of the patients were asymptomatic. 6. The average body weight of patients, 64.5±8.5kg in the male and 55.5±8.8kg in the female, was greater than those of the control group, 62.9±8.5kg and 52.5±5.0kg, respectively, but there was no statistically significant differenceir=0.150).