Prevalence of Malassezia species in pitiriasis versicolor lesions

GIUSIANO G; SOSA MA; ROJAS F; MANGIATERRA M; TOMA VANACORE S; CARRILLO MUÑOZ AJ

Torino, Italia

Congreso; 3rd Trends in Medical Mycology; 2007

Pityriasis versicolor is a chronic, bening skin disease that is generally asymptomatic. It occurs world wide and it is very common in tropical and temperate regions. It affects predominantly young adults of both sexes and its clinical lesions are slightly scaly maculae that vary in color, being  hypopigmented (white) to hyperpigmented (pink, tan, brown). This disease occurs when Malassezia yeast, that normally colonizes the skin, changes from its saprophytic state to pathogen and invades the stratum corneum of the skin. Resistencia city is located in the northeast border of Argentina (27º55’S - 58º22’O). This area has a subtropical climate with a prominent dry season and is covered with xerophilic forest adapted to recurring sequences of drought and flood. M. globosa and M. sympodialis were the most frequent species isolated (75%) as referred in others reports. Although in this work they appear in similar percentages. It’s noteworthy the isolation of the primary zoophylic M. pachydermatis from trunk, arm and neck of a young man. PCR-RFLP allowed the detection and characterization of Malassezia species mixtures (8,25%), which are difficult to discriminate with other molecular techniques and almost impossible with conventional physiological and biochemical tests. Most of PV lesions were observed in trunk and back. Lesions in sites considered less frequent, as neck, face and groin, were observed. M. globosa, showing a wide distribution, was also isolated from face and neck. M. furfur is less frequent in face and neck. The high prevalence of PV (57,3%) was observed in 21-40 years old group. This is a contribution to the knowledge of Malassezia genus ecology