Background: Atopic dermatitis will persist into adult life and chronic severe atopic dermatitis may cause significant interference in social interaction. Despite the controversy concerning the existence of specific personality exhibited by patients with atopic dermatitis, psychological and social factors have long been considered important factors that have influence on the course of the disease. Objective : The purpose of this study was to investigate the charateristics of the personalities of adult patients with atopic dermatitis and their relationship to psychological factors and clinical characteristics. Methods : Eysenck Personahty Questionnaire(EPQ) was carried out on 54 adult patients with atopic dermatitis. Using the EPQ scores, a cluster analysis was done to identify the subgroup of psychologically disabled patients. The psychological and social aspects of the identified patients were then investigated using a designed questionnaire. Results : 1. A cluster analysis identified two patient subgroups. Psychoticism(P), extroversion-introversion(E), and neuroticism(N) scores were significantly different between the subgroups. The neuroticism scores were above the upper limit of the normal range in the higher EPQ scored subgroups. However, the total clinical severity score which was evaluated in 25 patients showed no significant difference between these subgroups. 2. The higher psychoticism, extroversion-introversion, and neuroticism scored patients tended to express severe disability due to atopic dermatitis and a high level of stress which was evaluated by the designed questionnaire. Conclusion : Eysenck personality questionnaire can be helpful in identifying a subgroup of patients who may need psychiatric intervention. (Kor J Dermatol 1996;34(3): 359-365)