Sebaceous gland diseases are a group of common dermatological diseases with multiple causes. To date, a systematic report of the risk factors for sebaceous gland diseases in adolescents has not been published. The aim of this study was to assess the prevalence and risk factors for certain sebaceous gland diseases (seborrhea, seborrheic dermatitis, acne, androgenetic alopecia and rosacea) and their relationship to gastrointestinal dysfunction in adolescents. From August-October, 2002-2005, a questionnaire survey was carried out to obtain epidemiological data about sebaceous gland diseases. Using random cluster sampling, 13 215 Han adolescents aged 12-20 years were recruited from four countries or districts (Macau; Guangzhou, China; Malaysia; and Indonesia). The statistical software SPSS ver. 13.0 was used to analyze the data. The prevalence of seborrhea, seborrheic dermatitis, acne, androgenetic alopecia and rosacea was 28.27%, 10.17%, 51.03%, 1.65% and 0.97%, respectively. Based on multivariate logistic regression analysis, the risk factors for sebaceous gland diseases included: age; duration of local residency; halitosis; gastric reflux; abdominal bloating; constipation; sweet food; spicy food; family history of acne; late night sleeping on a daily basis; excessive axillary, body and facial hair; excessive periareolar hair; and anxiety. There was a statistically significant difference in the prevalence of gastrointestinal symptoms (halitosis; gastric reflux; abdominal bloating; constipation) between patients with and without sebaceous gland diseases (chi(2) = 150.743; P = 0.000). Gastrointestinal dysfunction is an important risk factor for diseases of the sebaceous glands and is correlated with their occurrence and development.

Tinea capitis remains a common public health problem worldwide especially in developing areas. Aetiologic agents and clinical pattern vary with geography and history of socioeconomic conditions. Three community surveys and a prospective study were carried out over the past 50 years (1965-2014) in the Qingyunpu District of Nanchang, Southern China. Clinical presentation and spectrum of aetiological agents were monitored to understand the evolution of tinea capitis. In 1965 favus was highly epidemic and Trichophyton schoenleinii presented as the overwhelming aetiological agents of scalp infection in the study area, with a prevalence of 3.41% of the population. During a governmental campaign to eliminate tinea capitis initiated in mid of 1960s, favus was successfully controlled and the prevalence decreased to less than 0.01% in 1977. After that period, clinical presentation and spectrum of fungi changed with social development. Trichophyton schoenleinii was replaced by Trichophyton violaceum and Trichophyton mentagrophytes. Nowadays, the species corresponds with a dominant black dot type of tinea capitis in the Nanchang area. The prevalence of causative agents of tinea capitis is not only related to geography but also to socioeconomic factors. Multiple factors have to be considered for the management for control of this disease.

This epidemiological survey was a retrospective study on three nodes during the past three decades on fungal infections representing the China, including Taiwan. Owing to rare publications reporting on dynamic epidemiological trends in the pathogen epidemiology in China, we surveyed the isolation rates and pathogenic fungi from 8 representative districts in China using uniform identification with uniform methodology. The pathogenic fungi isolation rates and species obtained from 1986 (n=9,096), 1996 (n=19,009), and 2006 (n=33,022) suggested that Trichophyton rubrum was the commonest organism cultured in 1980s (45.4%) and 1990s (34.5%), but Candida albicans increased significantly and reaching to its peak (26.9%) in 2006s' survey, and has become the most common isolate of fungal infections in China currently. In addition, Candida glabrata became the most common non-albicans species of Candida in 2006s' survey. At the same time, the incidence of molds also gradually increased. According to comparative analysis of the results of these three surveys, we found apparent differences in the isolation rates of different pathogenic fungi and the forefront 10 species in China varied significantly, and the dermatophytes decreased markedly, while yeasts, especially the Candida species and the molds, increased gradually during the past three decades. Less dermatophytic infections may suggest better access to healthcare or increase in Candida species indicated higher incidence of hospital acquired infections.