The 'tape-method': a new and simple method for quantitative culture of Pityrosporum yeasts.

A new method for quantitative culture of Pityrosporum yeasts, the 'tape-method', is presented. Samples for culture were taken from the skin by stripping with 1 cm2 of tape, whereafter the tapes were placed over a drop of sterile olive oil which was pipetted on a Sabouraud medium. Plates were incubated at 37 degrees C, and after 7 days the numbers of Pityrosporum colonies growing under the tapes were counted. With this method a difference in numbers of Pityrosporum colonies between seborrheic dermatitis and normal skin could be discerned. This difference was significant. It appeared that two successive strippings were sufficient for quantitative culture. The 'tape-method' appeared to be a reliable and inexpensive diagnostic tool.