Comparison between Malassezia Folliculitis and Non-Malassezia Folliculitis.

Abstract

BACKGROUND: Among the various types of folliculitis, differentiation of

Malassezia folliculitis (MF) from other forms of folliculitis is important

because it is usually treated with antifungal agents. OBJECTIVE: We attempted to

find a method to enhance the detection rate of MF, and examined the differences

in the clinical manifestation between MF and non-MF (NMF). METHODS: We performed

a retrospective study involving patients with folliculitis who were previously

diagnosed with MF or NMF on the basis of serial tissue sectioning and

diastase-Periodic acid-Schiff (d-PAS) staining findings. The clinical features of

MF and NMF were compared. RESULTS: Among a total of 100 folliculitis patients, 20

were diagnosed with MF and 80 with NMF. Tissues from the 80 patients with NMF

were sectioned serially into 10 slices and stained with hematoxylin and eosin

stain; among these, 10 had many round-to-oval yeast organisms in the hair

follicles that confirmed MF. Finally, d-PAS staining was used to detect the

presence of yeast in the NMF slides. Notably, among the 70 d-PAS-stained samples,

yeast organisms were found in 6 samples, confirming MF. As a result, the

diagnosis of 16 patients changed from NMF to MF. Compared with NMF, MF showed

major involvement of the trunk and low involvement of the face and legs as well

as male predilection. CONCLUSION: Physicians should consider serial sectioning

and/or d-PAS staining of folliculitis lesions, particularly of those on the trunk

of male patients, even if no yeast organisms are detected initially.