RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Acitretin may be an effective treatment for skin disease and skin cancer. PURPOSE: Phase II trial to study the effectiveness of acitretin in treating patients who have skin disease or skin cancer.

OBJECTIVES: I. Determine the long-term safety and efficacy of acitretin in patients with psoriasis, cutaneous disorders of keratinization, multiple basal cell carcinomas, or other retinoid-responsive diseases or malignancies.

PROTOCOL OUTLINE: Patients receive oral acitretin daily in the absence of disease progression or unacceptable toxicity.

PROJECTED ACCRUAL: A total of 130 patients will be accrued for this study.

Criteria

PROTOCOL ENTRY CRITERIA:

--Disease Characteristics--

• Diagnosis of psoriasis, cutaneous disorders of keratinization, or other retinoid-responsive disorders or malignancies OR Diagnosis of multiple basal cell carcinomas resulting from one of the following: Nevoid basal cell carcinoma syndrome; Xeroderma pigmentosum; Arsenical insecticide exposure; Sunlight exposure X-irradiation
• Widespread involvement (e.g., psoriasis involving 10% or more of body surface area OR Severe, recalcitrant localized involvement (e.g., keratoderma palmaris et plantaris)
• Female patients must have disease that is severe and recalcitrant to all other standard therapies

--Prior/Concurrent Therapy--

• No chronic intake of excessive vitamin A exceeding 25,000 IU/day

--Patient Characteristics--

• Age: Any age
• Performance status: Not specified
• Life expectancy: Not specified
• Hematopoietic: Not specified
• Hepatic: No persistently abnormal liver function tests; SGOT or SGPT no greater than 3 times upper limit of normal (ULN)
• Renal: No persistently abnormal renal function tests; Creatinine no greater than 3 times ULN
• Other: No persistent pretreatment hypertriglyceridemia (greater than 300 mg/dL); No significant neurological, musculoskeletal, or other internal medical disorder that would preclude retinoid therapy; Not pregnant; Negative pregnancy test; Fertile patients must use effective contraception during and for 3 years after study