Childhood tinea incognito caused by Trichophyton mentagrophytes var. interdigitale mimicking pustular psoriasis.

Tinea incognito refers to fungal infection whose clinical appearance is modified or aggravated by administration of systemic or topical corticosteroids. We report a case of pustular psoriasis-like tinea incognito caused by Trichophyton mentagrophytes var. interdigitale under topical corticosteroid therapy. Sequence analysis of the internal transcribed spacer 2 region, in addition to the D1D2 domain of the 26S ribosomal RNA gene, was helpful in identifying the fungal species.