In 11 double-blind trials in 264 patients using ketoconazole shampoo, 2% for the treatment of dandruff or seborrheic dermatitis, an increase in normal hair loss and irritation occurred in less than 1% of patients. In three open-label safety trials in which 41 patients shampooed 4-10 times weekly for six months, the following adverse experiences each occurred once: abnormal hair texture, scalp pustules, mild dryness of the skin, and itching. As with other shampoos, oiliness and dryness of hair and scalp have been reported. In a double-blind, placebo-controlled trial in which patients with tinea versicolor were treated with either a single application of ketoconazole shampoo, 2% (n=106), a daily application for three consecutive days (n=107), or placebo (n=105), drug-related adverse events occurred in 5 (5%), 7 (7%) and 4 (4%) of patients, respectively. The only events that occurred in more than one patient in any one of the three treatment groups were pruritus, application site reaction, and dry skin; none of these events occurred in more than 3% of the patients in any one of the three groups.
In worldwide experience with ketoconazole shampoo, 2% there have been reports of hair discoloration and abnormal hair texture, itching, skin burning sensation, contact dermatitis, hypersensitivity, angioedema, alopecia, rash, urticaria, skin irritation, dry skin, and application site reactions. Because these reactions are reported voluntarily from a population of uncertain size, it is not possible to reliably estimate their frequency.