Immunophenotyping comparison of inflammatory cells between Malassezia folliculitis and pityriasis versicolor lesions.

UNLABELLED: Immunophenotyping of inflammatory dermal infiltrates in Malassezia folliculitis (MF) and pityriasis versicolor (PV) lesions is less reported. Immunohistochemistry was performed on 21 MF lesions, 10 PV lesions, and 10 control skin. CD3+, CD4+, CD8+, CD20+, CD68+, and CD117+ cells were increased in MF compared with PV and normal skin (P < 0.01-0.05), while CD3+, CD4+, and CD20+ cells were higher in PV than in normal skin (P < 0.05). Dermal CD1a+ cells were higher only in PV (P < 0.05). Although both cellular and humoral immune responses are involved in pathogenesis of MF and PV, their difference may contribute to clinicopathological discrepancy between two disorders.

LAY SUMMARY: Malassezia folliculitis and pityriasis versicolor are common Malassezia-induced superficial mycoses. Their clinicopathological discrepancy may be due to the difference of cellular and humoral immune responses.