Background: Erythroderma is a rare skin disorder, and studies on its incidence and causes are lacking. The annual incidence has been estimated to be 1 to 2 patients per 100,000 inhabitants. Objective: We investigated the incidence and cause of erythroderma in an unselected population and evaluated the referral pattern of erythrodermic patients by nonacademic dermatologists. Methods: A survey was performed among all nonacademic dermatologists in The Netherlands, using a mailed questionnaire. Questions dealt with the number of patients diagnosed with erythroderma in the year 1997, the cause of the erythroderma, and whether these patients were referred to a university hospital. A questionnaire was also sent to all university hospitals. Results: Seventy-eight percent of the nonacademic dermatologists answered the questionnaire, and all 8 university hospitals responded. In the year 1997, 141 patients were diagnosed with erythroderma in The Netherlands. The annual incidence of erythroderma based on these figures is 0.9 patients per 100,000 inhabitants. Compared with the university hospitals, erythroderma was more often diagnosed as an exacerbation of preexisting dermatoses (61% vs 51%; P = .37) and less often as idiopathic (14% vs 31%; P = .04) among the nonacademic dermatologists. Cutaneous T-cell lymphoma was rarely the cause, occurring in only 1% of patients diagnosed by the nonacademic dermatologists but in 6% of patients at the university hospitals. Overall, only 37% of nonacademic dermatologists referred patients with erythroderma to a university hospital. Conclusions: The incidence of erythroderma in The Netherlands is slightly lower than the earlier estimate in the literature. Moreover, the cause of erythroderma is different among patients diagnosed in an academic and a nonacademic setting. The majority of dermatologists in The Netherlands treat patients with erythroderma themselves and do not refer these patients to university hospitals. (J Am Acad Dermatol 2001;45:675-8.)