Chromatic Variants of Pityriasis Versicolor and Molecular Species Identification Using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP).

BACKGROUND

Pityriasis versicolor (PV) is a common superficial mycosis caused by Malassezia species. To describe the clinical and epidemiological characteristics of PV in Acapulco, Mexico, and to identify the associated Malassezia species using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

METHODS

A cross-sectional study was conducted in 2024 at Acapulco General Hospital and a private dermatology clinic. Patients with clinically suspected PV and no recent antifungal or immunosuppressive treatment were enrolled. Skin scales were examined microscopically and cultured on modified Dixon agar. Isolates were identified using conventional methods and PCR-RFLP with HhaI and BstCI enzymes.

RESULTS

Sixty-nine patients were included; 68.1% were male, and the most affected age group was 11-20 years (34.8%). The hypochromic variant predominated (63.8%). PCR-RFLP identified M. globosa (33.3%) and M. furfur (31.9%) as the most frequent species, followed by M. restricta, M. sympodialis, and M. slooffiae. Species identification was unsuccessful in 11.6% of isolates. No statistically significant associations were found between clinical variants, gender, or species distribution.

CONCLUSIONS

M. globosa and M. furfur were the predominant species in this tropical Mexican cohort. PCR-RFLP is a practical option for species-level identification, highlighting the diversity of Malassezia in PV.