Falsely Elevated Urinary Level of Vanillylmandelic Acid Induced by Griseofulvin

• A 6-year-old girl with mild hepatitis was found to have an elevated urinary level of vanillylmandelic acid (VMA), but no cause for the elevation was found. The patient was receiving griseofulvin for treatment of tinea capitis, and this drug was suspected of causing a falsely elevated urinary VMA level. Four other patients receiving griseofulvin were also found to have elevated urinary VMA levels. In one patient, urinary VMA level determined by an alternate method was normal. ( Arch Dermatol 1989;125:269-270)