Tinea Versicolor Disguised as Pityriasis Alba: How to Deal with Confusing Skin Hypopigmentation

Abstract

Tinea versicolor is a skin disorder that is due to an overgrowth of the saprophytic fungi Malassezia sp. It causes lighter or darker patches on the skin. Several skin diseases must be considered in the differential diagnosis of hypopigmented skin patches (vitiligo, Bier's spots, pityriasis rotunda, Pityriasis alba).Pityriasis alba and tinea versicolor may look similar, but their causes differ. Pityriasis alba's red, scaly patches stem from factors like UV, wind exposure, bathing habits, and low copper levels, unlike tinea versicolor's fungal origin.A 8-year-old presented hypopigmented small spots on the right cheek. Regular sun exposure and the small size of the lesions on the face resulted in an initial misdiagnosis of pityriasis alba. Finally, confirmative diagnosis of tinea versicolor was supported by the clinical appearance of lesions (hypopigmented, scaly macules), on the presence of greenish-yellow fluorescence under Wood's lamp, and on direct microscopic examination of scales. This case highlights the importance of carefully examining and investigating hypopigmented lesions, particularly when they present with features suggestive of both pityriasis alba and tinea versicolor. While some clinical characteristics, such as location and size, may offer initial clues, relying solely on these factors can lead to misdiagnosis. The similarity of the two skin conditions requires a Wood's lamp test and confirmatory mycological diagnosis.

Atypical and Unpredictable Superficial Mycosis Presentations: A Narrative Review

“…The presence of greenish-yellow fluorescence under Wood's light would strongly suggest tinea versicolor, while a negative result, associated to the absence of yeast on tape stripping examination, solidifies the diagnosis of pityriasis alba [187,188] (Figure 11). in these disorders.…”

“…The presence of greenish-yellow fluorescence under Wood's light would strongly suggest tinea versicolor, while a negative result, associated to the absence of yeast on tape stripping examination, solidifies the diagnosis of pityriasis alba [187,188] (Figure 11). Pityriasis rotunda is a rare disorder of keratinization characterized by persistent, hyperpigmented or hypopigmented, geometrically perfect circular patches of dry ichthyosiform scaling with no inflammatory changes.…”