Bayaraa B, et al. - Researchers evaluated the association between sex difference and habitual/environmental status, age and incidence of familial psoriasis by analyzing data from the Fukuoka University Psoriasis Registry. Overall in 6.3% of patients, a familial history of psoriasis was seen, Nonetheless, female patients showed a significantly higher rate than men. In young women who experienced fewer environmental factors such as smoking and drinking, genetic factors were seen to have a stronger influence. A significantly higher prevalence of smoking and drinking habit, known as risk factors for psoriasis, was seen in men. This was the first study that demonstrated that there is a difference in the incidence of familial psoriasis depending on the age of onset of psoriasis in Japan.