A study on the extent, aetiology and associated factors of dandruff in a group of medical students and the in vitro effects of antidandruff preparations

 Dandruff is a scalp disorder, characterized by itching and rapid skin flaking of the scalp of a person. Yeasts of the genus Malassezia are responsible for dandruff. The prevalence of dandruff in South Asia is 60.1%, whereas in the world it is 50%. The objectives of this study were to ascertain the prevalence, describe associated factors, isolate Malassezia sp. from dandruff samples of medical students and test the anti-fungal effects of commercially available shampoo and crude extracts of commonly used herbs against Malassezia. Methods: Ninety five students were chosen by systematic sampling. A self-administered questionnaire was used for data collection. Samples of skin flakes/swabs was collected from the scalp of participants. Specimens were examined using three direct microscopic methods. Fungal colonies isolated on Saborauds/Dixon Agar were identified using Gram stain and catalase test. Antifungal activity of six shampoo brands and crude extracts of eleven herbs were tested against isolated Malassezia sp. by agar well/disc diffusion method. Results: Prevalence of dandruff was 64.2% in the study group. The typical ‘spaghetti and meatball’ appearance was seen in the skin flakes taken from 44 of 61 (72.1%) students. Malassezia sp. was isolated only from 49 of the 61 students (80.3%). In-vitro, anti-malassezial effect (Inhibition zone (IZ)>10mm) was observed in 4 of the 7 tested ‘anti dandruff’ shampoos. Crude extracts of fresh leaves of Psidium guavava (guava), flowers of Punica grantum (pomegranate) and fruits of Solanum lycopersicum (tomato) and Citrus hystrix (Kaffir lime) showed IZs > 10mm. Conclusion: Prevalence of dandruff in the studied group of medical students was higher than in the Asian population. Four of the tested ‘anti dandruff’ shampoos and crude extracts of leaves of P. guavava (guava), fruits of S. lycopersicum (tomato), C. hystrix (kaffir lime), and flowers of P. grantum (pomegranate) showed an in-vitro inhibitory effect on the growth of Malassezia sp.