Fluorescence from pilosebaceous follicles.

Fluorescence studies were performed on the extrusions from pilosebaceous follicles. Pressure extractions produced follicle samples which showed fluorescence under Wood's light. The samples were then analysed in a fluorometer giving corrected excitation spectra. The structured emission spectra achieved were interpreted as being due to porphyrins produced by Propionibacterium acnes (P. acnes). Details in the spectra showed close resemblance to spectra from cultured P. acnes cells. The emission spectra showed distinct features in all the four subjects investigated (who were different with respect to age, sex, follicle sampling area, and tendency to acne) and dominant peaks due to at least three porphyrins were found. The concentrations of these porphyrins vary from case to case. Excitation spectra were recorded and supported the assumption that the fluorescent emission was partly due to coproporphyrins and metalloporphyrins in the samples. Free protoporphyrins did not seem to be present in the extrusions. The excitation spectra, in particular, vary from person to person but seem to be constant over time in one and the same subject.