CLINICAL AND LABORATORY INVESTIGATIONS DOI 10.1111/j.1365-2133.2005.07114.x Distribution of Malassezia species in pityriasis versicolor and seborrhoeic dermatitis in Greece. Typing of the major pityriasis versicolor isolate M. globosa G. Gaitanis,* A. Velegraki,* E.C. Alexopoulos,* V. Chasapi,à A. Tsigonia§ and A. Katsambas  *Mycology Laboratory, Microbiology Department, and  Dermatology Clinic, Medical School, University of Athens, Athens, Greece à3rd Dermatology Department, ‘A. Sygros’ Hospital, Athens, Greece §School of Health and Welfare, Technological Educational Institute, Athens, Greece Correspondence George Gaitanis, Mikras Asias 75-77, Athens 115 27, Greece. E-mail: ggaitanis@med.uoa.gr Accepted for publication 28 September 2005 Key words Malassezia, pityriasis versicolor, seborrhoeic dermatitis, single-strand conformational polymorphism analysis Conflicts of interest None declared. Summary Background The expansion of the genus Malassezia has generated interest in the epi- demiological investigation of the distribution of new species in a range of der- matoses, on which variable results have been reported from different geographical regions. No data are thus far available from South-east Europe (Greece). Objectives To study the distribution of Malassezia species in pityriasis versicolor (PV) and seborrhoeic dermatitis (SD) and to investigate whether polymorphisms in the internal transcribed spacer (ITS) 1 region facilitate detection of M. globosa and M. sympodialis subtypes. Methods In total, 109 patients with PV and SD and positive Malassezia cultures were included in the study. Age, gender, primary ⁄ recurrent episode, disease extent and clinical form of PV were recorded. ITS 1 polymorphisms of M. globosa and M. sympodialis type and clinical strains were investigated by polymerase chain reaction (PCR)–single-strand conformational polymorphism (SSCP) analysis. Results Malassezia globosa was the prevalent species isolated from PV and SD either alone (77% and 39%, respectively) or in combination (13% and 18%, respect- ively) with other Malassezia species. The pigmented form of PV was strongly corre- lated with the female gender. PCR–SSCP differentiated five subgroups of M. globosa with one being associated with extensive clinical disease. All M. sympodialis isolates displayed a homogeneous ITS 1 PCR–SSCP profile. Conclusions Malassezia species isolation rates were in agreement with those reported from South-west Europe. PCR–SSCP of the ITS 1 is useful for highlighting pros- pective clinical implications of M. globosa subtypes. Malassezia yeasts cause pityriasis versicolor (PV) 1 and are impli- cated in the pathogenesis of various dermatoses with universal distribution such as atopic dermatitis (AD) 2 and seborrhoeic dermatitis (SD), 1 while recent information suggests their involvement in psoriasis. 3 Although the isolation of Malassezia species from patients with PV was performed by Gordon in 1951, experimental inoculations on the skin of healthy indi- viduals have failed to reproduce lesions. 4 SD is triggered through a nonimmune-mediated mechanism, 5 while flares of AD and psoriasis can be elicited by this yeast through its abil- ity to activate specific T-helper cell-mediated pathways. 3 Since the enlargement of the genus in 1996 to include seven species (M. furfur, M. sympodialis, M. globosa, M. restricta, M. slooffiae, M. obtusa and M. pachydermatis 6 ), three more lipid-dependent species have been appended to the genus: M. dermatis 7 and M. japonica 8 isolated from patients with AD in Japan, and the ani- mal isolate M. nana. 9 The expansion of the genus has stimulated epidemiological surveys regarding the distribution of the new species in PV, SD, AD 10–12 and healthy subjects. 13 Moreover, studies involving the contribution of different allergens in the pathogenesis of AD 2 have taken place while different Malassezia species have been scrutinized for the existence of potential poly- morphisms in sequences coding for the first major allergenic protein (Mal s 1). 14 Published epidemiological data suggest geo- graphical variations in the rate of the isolated species, and molecular typing methods have been developed to evaluate the distribution of different Malassezia subtypes within a given disease spectrum. The instability of certain Malassezia species in culture 15 and especially of the commonly isolated M. globosa has led to the direct identification of Malassezia species from DNA extracted 854 Ó 2006 British Association of Dermatologists • British Journal of Dermatology 2006 154, pp854–859