Malassezia interaction with a reconstructed human epidermis: Keratinocyte immune response.

The immediate immune response developed by the keratinocytes against Malassezia yeasts has been addressed yielding conflicting results. This study aims the assessment of cytokines and antimicrobial peptides gene expression elicited by M. sympodialis and M. furfur once in contact with a reconstructed human epidermis. A yeast suspension was prepared in RPMI 1640 medium (Sigma-Aldrich, St. Louis, MO) supplemented with Tween 60 and oleic acid to obtain approximately 1 × 106 cells in a volume of 100 µL. Clinical isolates of M. sympodialis (from pityriasis versicolor) and M. furfur (from seborrhoeic dermatitis) were inoculated, separately, onto a reconstructed human epidermis. A distinct expression pattern was found between the two tested species, with a tendency for overexpression of pro-inflammatory cytokines very soon after infection, whereas no significant expression or gene downregulation was often noticed following 24 and 48 h of incubation. A possible Malassezia species-dependent immune response pattern is highlighted.

Spitz/Reed nevi: a review of clinical-dermatoscopic and histological correlation.

BACKGROUND: Spitz/Reed nevi are melanocytic lesions that may mimic melanoma at clinical, dermatoscopic and histopathological levels. Management strategies of these lesions remain controversial. OBJECTIVES: We aim a correlation among clinical-dermatoscopic and histological features of a series of Spitz/Reed nevi diagnosed during 7 years at the Department of Dermatology. METHODS: Clinical, dermatoscopic and histological features of Spitz/Reed nevi diagnosed at our tertiary hospital from 2008 to 2014 were reviewed in order to seek correlation. RESULTS: All described dermatoscopic patterns for Spitz/Reed nevi were found among the 47 enrolled patients; starburst and atypical/multicomponent patterns prevailed (57.4%). Reticular pattern predominated among children younger than 12 years, whereas homogeneous pattern was more frequent in patients older than 12 years, although these differences were not statistically significant (P=0.785). Among histological atypical lesions, all dermatoscopic patterns were represented, but the atypical/multicomponent predominated (56.3%). Two out of 11 dermatoscopically atypical lesions did not show histopathological counterpart. CONCLUSIONS: The excision of Spitz/Reed nevi in adults is supported, given the inability to accurately predict those with histopathological atypia, based on clinical and dermatoscopic features, which may raise concern about malignancy.