Influence of hair oil on scalp fungal cultures.

It has been clinically speculated that the use of oil for hair grooming may change detection of fungus on culture; however, the effect of hair oil on fungal cultures remains poorly studied. In this prospective case-controlled study, scalp cultures were collected from twenty-eight pediatric patients with clinically suspected tinea capitis before and after cosmetic hair oil was rubbed into the scalp. Following hair oil application, fifteen of the sixteen originally positive patients tested positive, while one patient that had tested negative prior to hair oil had a positive culture. Our study suggests that recent hair oil application has minimal effect on the sensitivity of fungal culture for tinea capitis and we can rely on our standard fungal cultures with or without hair oil.