Long-term follow-up of 344 Shanghai psoriatics

344 patients with psoriasis vulgaris treated in Huashan Hospital, Shanghai were followed up for 7-30 years. 13% of them developed arthralgia and 2% had joint deformities. One patient developed erythroderma due to dexamethasone medication. Internal malignancy occurred in 2 patients (0.58%). The severity of the course of the disease was neither influenced by family history nor alcoholism, but was markedly influenced by the duration of illness and administration of anti-neoplastic drugs.