Abstract Generalized pustular psoriasis (GPP) is a rare but notoriously recalcitrant cutaneous diseases. Therefore, there have been few reports of more than ten patients with GPP who were treated at the same institution. The sever- ity of this disease and its response to each therapeutic modality vary among patients. In some GPP is life-threat- ening, but in others it may show a benign, chronic course for a long period of time. Before starting treatment, a knowledge of the therapeutic efficacy and side effects of each drug used in the treatment of GPP is necessary. In our multicenter study, we compared the effectiveness of and adverse reactions to several systemically adminis- tered drugs. Following the development of a unique clas- sification of the disease severity based on scoring the clin- ical symptoms and the laboratory findings, we propose here therapeutic guidelines for the treatment of GPP. Keywords Generalized pustular psoriasis Basic concept and objectives of the therapeutic guidelines for GPP Basic concept The concepts on which we based the guidelines for treat- ment of GPP were as follows: (1) the guidelines are for dermatological specialists who treat patients with GPP, (2) diagnostic criteria for GPP are specified, (3) all major therapeutic drugs available in Japan are listed, (4) new guidelines for the assessment of disease severity are pre- sented, (5) concrete advice and life-style suggestions based on the results of a multicenter epidemiological study are presented, and (6) the guidelines will be reviewed, revised or expanded from time to time to reflect not only the opin- ions of the members of this research team, but also those of a wide range of dermatologists. The present goal of GPP treatment Because no radical therapy to cure GPP is yet available, the main therapeutic goal at present should be to improve the patients’ quality of life (QOL) and help them to enjoy a normal social life with almost no interference from the disease. Objective of the guidelines Because GPP is a rare disease, it is difficult to conduct a comparative study among the therapeutic modalities at a single medical institution. This study team has prepared diagnostic criteria based on the findings obtained in a na- tionwide survey as well as the reported findings regarding current treatments. The team’s objective is now to draft therapeutic guidelines based on these findings. Y. Umezawa · A. Ozawa · T. Kawasima · H. Shimizu · T. Terui · H. Tagami · S. Ikeda · H. Ogawa · A. Kawada · T. Tezuka · A. Igarashi · S. Harada Therapeutic guidelines for the treatment of generalized pustular psoriasis (GPP) based on a proposed classification of disease severity Arch Dermatol Res (2003) 295 : S43–S54 DOI 10.1007/s00403-002-0371-6 Published online: 8 March 2003 ORIGINAL PAPER Y. Umezawa (✉) · A. Ozawa Department of Dermatology, Sensorium and Cutaneous Medicine, Tokai University School of Medicine, Isehara, Japan e-mail: umeume@is.icc.u-tokai.ac.jp T. Kawasima · H. Shimizu Department of Dermatology, Graduate School of Medicine, Hokkaido University, Sapporo, Japan T. Terui · H. Tagami Department of Dermatology, Graduate School of Medicine and School of Medicine, Tohoku University, Sendai, Japan S. Ikeda · H. Ogawa Department of Dermatology, School of Medicine, Juntendo University, Tokyo, Japan A. Kawada · T. Tezuka Department of Dermatology, School of Medicine, Kinki University, Osaka, Japan A. Igarashi · S. Harada Dermatological Clinic of Kanto Medical Center, NTT East Corporation, Tokyo, Japan © Springer-Verlag 2003