Identification and speciation of Malassezia in patients clinically suspected of having pityriasis versicolor

Abstract

Background:Malassezia is a lipid-dependent yeast known to cause Pityriasis versicolor, a chronic, recurrent superficial infection of skin and present as hypopigmented or hyperpigmented lesions on areas of skin. If not diagnosed and treated, it may lead to disfigurement of the areas involved and also result in deep invasive infections.Aim:The aim of the present study was to identify and speciate Malassezia in patients clinically suspected of having Pityriasis versicolor.Materials and Methods:Total 139 patients suspected of having Pityriasis versicolor were evaluated clinically and diagnosis was done by Wood's lamp examination, confirmed mycologically by using KOH, cultivation on Sabouraud's dextrose agar and modified Dixon agar at a tertiary care hospital in Mumbai. The total duration of study was 12 months.Results:Majority of the patients were males (59.71%) in the age group of 21-30 years (33.81%) who were students (30.21%) by profession. The incidence of Malassezia in Pityriasis versicolor was 50.35%. The most common isolate was M. globosa (48.57%), followed by M. furfur (34.28%). Majority of the patients had hypopigmented lesions, with M. globosa as the predominant isolate. Neck was the most common site affected; 88.48% were Wood's lamp positive of which 56.91% of Malassezia isolates grew on culture. KOH mount was positive in 82.01% of which 61.40% Malassezia isolates grew on culture.Conclusions:The procedure of culture and antifungal testing is required to be performed as different species of Malassezia are involved in Pityriasis versicolor and susceptibility is different among different species. Thus, it would help to prevent recurrences and any systemic complications.

Clinico-epidemiological study of pityriasis versicolor in a rural tertiary care hospital

“…The type of lesions seen in our study were more of hypopigmented variety followed by hyperpigmented and mixed types in 80%, 15.2% and 4.7% respectively, which correlated with the findings made by Shah et al 7 (hypo pigmented (84.17%), hyperpigmented (8.63%), mixed (7.19%), Krishnan et al 6 (hypo pigmented (84%), hyperpigmented (9%), mixed (6%)), Kabbin et al 10 (hypo pigmented (67%), hyper pigmented (31%), mixed (2%) ), while Rao et al 9 observed mixed variety in 16.60%., hyperpigmented in 8.30%. This variation in the morphological appearance of lesions may be due to differences in climatic conditions and different study population.…”

“…The most common affected age group was 21-30years followed by 11-20 years. Similar findings were given by Kaur et al 3 (Age group 20-30 years), Shah et al 7 (Age group 21-30 years), Krishnan et al 6 (15-29 years), suggesting that the peak of infection coincides with the sebum production and hormonal influence.…”

Malassezia species in healthy skin and in dermatological conditions

“…Several groups have published studies examining the mycology of PV. In particular, the species most commonly cultured was M. globosa , which was isolated from between 49 and 97% of cases (Table ) . Recently, two further studies both reported M. globosa as the predominating species isolated from PV lesions.…”

“…However, other studies from North and South America have reported M. sympodialis to be the predominant isolate and report frequencies of 59%, 38%, and 30%, respectively . Malassezia furfur , by contrast, was isolated less frequently by many investigators, who reported it as the second or third species, although an Indonesian, culture‐based study described it as the first causative agent …”

“…In particular, the species most commonly cultured was M. globosa, which was isolated from between 49 and 97% of cases (Table 1). 3,[23][24][25][32][33][34][35][36][37][38][39][40][41][42] Recently, two further studies both reported M. globosa as the predominating species isolated from PV lesions. In the first study, from India, M. globosa was found in 52% of cases.…”