BACKGROUND:Prisoners have heightened health needs, and only recently has the importance of skin diseases in this group been recognized. The aim of this study was to estimate the prevalences of dermatological diseases among prisoners in the jails of southern Lazio and to investigate the determinants of these. METHODS:A cross-sectional study was carried out in three jails in southern Lazio. Retrospective data collection for sociodemographic characteristics, lifestyle habits, and health status was realized using patients' charts. RESULTS:The study sample consisted of 2653 male prisoners detained during 1995-2000. A total of 7.9% of the sample were found to have dermatological disease. The most common diseases were nonspecific dermatitis (3.1%), acne (1.5%), mycosis (1.4%), and scabies (0.7%). Multiple regression analyses were conducted to establish the associations of skin diseases with substance addiction status and age. In addition, a highly significant association emerged between length of detention and rate of dermatological disease. CONCLUSIONS:This study shows that habitual offenders, foreign inmates, prisoners serving long sentences, and prisoners who are illiterate are the most affected by dermatological disease. The conditions of detention may be the main reason; preventative strategies such as limiting overcrowding and the provision of electronic case sheets and a centralized database to collect and maintain patient clinical data might be effective in improving public health in jails.