Abstract:
Objective: To study the incidence and strains of Malassezia in infantile seborrheic dermatitis. Design: Cross-sectional descriptive study. Setting: Pediatric out-patients and in-patients units, King Chulalongkorn Memorial Hospital, Bangkok. Patients: Children aged less than 2 years with clinical diagnosis of infantile seborrheic dermatitis who received no steriod treatment for at least 1 month and who were examined at Deparment of Pediatrics, King Chulalongkorn Momorial Hospital, Bangkok. Method: Skin samples scraped from lesions of infantile seborrheic dermatitis were cultured in Sabouraud Dextrose Agar for 21 days. The DNA of Malassezia spp. Was detected by PCR method with conserved primers on ITS. After the product DNA was purified, sequencing and analyzing of both unknown samples and standard strains were done by using Clustal X Computer program to identify the species of Malassezia. Result: Infantile seborrheic dermatitis is found in the age groups of less than 2 months (64%) and 2-4 months (22%) respectively. The incidence of Malassezia spp. in infantile seborrheic dermatitis is 20 %. Malassezia furfur is found in 79% of the lesions of infantile seborrheic dermatitis whereas the other 21 % was contaminated by yeast of non Malassezia spp. Malassezia furfur is found in eyebrows (55%) and scalp (36%), respectively.Conclusion: The most common age group of infantile seborrheic dermatitis is less than 2 months. The incidence of Malassezia spp. in infantile seborrheic dermatitis is 20 %. The most common areas that Malassezia spp. is found are eyebrows, and scalp.