Hypercalcemia associated with oral isotretinoin in the treatment of severe acne

ISOTRETINOIN, or 13-cis-retinoic acid, is a derivative of vitamin A that has been found to be of benefit in a number of diseases characterized by abnormal keratinization, including Darier's disease and ichthyosis.1It is the most potent inhibitor of sebum secretion known and has been found to be effective in the treatment of severe nodulocystic acne in several trials. Its use has been reported to produce prolonged remission in some patients with severe cystic acne.2Although chronic vitamin A intoxication has been associated with hypercalcemia,3no similar association has been reported with the use of isotretinoin, to our knowledge. We report herein the occurrence of hypercalcemia in a patient with severe cystic acne treated with oral isotretinoin. Report of a Case A 19-year-old man with a two-year history of progressive, severe nodulocystic acne was seen at the University of California, Irvine Medical Center. The disease