“…19 It is therefore of great importance, especially in ambiguous cases, to carry out a detailed diagnosis, which, in addition to a precise anamnesis, always requires microscopy of the native preparation, the preparation of a culture and, if necessary, the biopsy of a suitable skin lesion. 20 Microscopically, numerous spores can usually be detected in affected hairs; a so-called endothrix growth pattern is observed, in which an invasion of the hair shaft takes place, making the pathogen almost invisible to wood light. 21 It is interesting to note that in our patients the number of microscopically visible spores did not correlate with the severity of the disease, so that even in pronounced foci on the scalp, sometimes only a few spores could be found.…”