Drug-induced acute pancreatitis associated with 22-oxacalcitriol ointment for treatment of psoriasis.

Hypercalcemia is usually caused by malignancies or primary hyperparathyroidism, and only rarely by drugs [1]. Hypercalcemia can occasionally cause acute pancreatitis [2]. We herein report a case of severe acute pancreatitis induced by hypercalcemia which developed as a reaction to ointment containing 22oxacalcitriol, a vitamin D3 analogue. A 72-year-old Japanese man with more than a 50-year history of psoriasis vulgaris developed generalized pustular psoriasis, which was refractory to combination therapy with corticosteroid and 22-oxacalcitriol ointments. He was referred to the Dermatology Dept. for further treatment. The patient’s clinical course is shown in Figure 1. Oral etretinate, an aromatic retinoid, was started, and the 22-oxacalcitriol ointment regimen was increased soon after admission. On hospital day 13, the skin lesions improved, but the patient developed abdominal discomfort and anorexia. As laboratory data showed an increased serum level of calcium (13.2 mg/dL; reference range: 8.7-10.0 mg/dL), the ointment was immediately discontinued. On hospital day 16, the patient developed severe abdominal pain, and was referred to the Gastroenterology Dept. for further evaluation and treatment. He had no history of trauma, abdominal surgery (except for an appendectomy) or biliary disease. Laboratory data showed leucocytosis (27,070 μL; reference range: 3,590-9,640 μL) and increased serum amylase levels (1,040 IU/L; reference range: 39-108 IU/L), lipase (114 IU/L; reference range: 0-41 IU/L), calcium (11.3 mg/dL) and CRP (27.6 mg/dL; reference range: 0-0.3 mg/dL) levels. The level of intact parathyroid hormone (PTH) was at the lower limit of the reference range (10 pg/mL; reference range 10-65 pg/mL) and PTH-related peptide was negative. Abdominal CT showed acute edematous pancreatitis with fluid collection in the peripancreas and prerenal space, but no evidence of gallbladder disease, bile duct dilatation or malignancies. In addition to the discontinuation of the 22-oxacalcitriol ointment, we administered an antibiotic and a protease inhibitor. This conservative treatment resulted in clinical and biochemical improvement. He has since been followed up for 11 months without any signs of recurrence. Topical vitamin D3 analogues are a well-established treatment for psoriasis [3]. Hypercalcemia has been reported as a serious adverse effect of these analogues but, in fact, many patients who develop such hypercalcemia are found to have exceeded the recommended dose regimen [4, 5, 6]. In our patient, in addition to long-term corticosteroid use and excessive