Mycoses in Thailand: Current Concerns

Abstract

Scytalidium dimidiatum is the leading cause of fungal foot diseases in Thailand, in contrast to similar studies in which dermatophytes have been identified as the predominant pathogens. By contrast, the prevalence of Candida albicans in our study was only 2.6-3.0%. Scytalidium fungal foot infection is clinically indistinguishable from that caused by dermatophytes and should be included as a possible cause of treatment failure in tinea pedis and onychomycosis. Without proper culture identification, clinically diagnosed patients would be treated with a standard antifungal regimen leading to minimal response and be interpreted as drug resistant cases resulting in switching of drugs and more aggressive management procedures.
Tinea capitis is another health problem in young children. However, for Microsporum canis and some ectothrix organisms, the effectiveness of treatment may be less than endothrix infection. Griseofulvin is still the mainstay antifungal although itraconazole and terbinafine are as effective. Pulse regimen may be another option with advantages of increased compliance and convenience. Two pulses of terbinafine may be sufficient for treating most cases of Microsporum infection, although additional treatment may be needed if clinical improvement is not evident at week 8 after initiating therapy.
Chromoblastomycosis is another subcutaneous infection that requires long treatment duration with costly antifungal drugs. The most common pathogen in Thailand is Fonsecaea pedrosoi. Preliminary study of pulse itraconazole 400mg/d 1 week monthly for 9-12 consecutive months showed promising results.
The prevalence of Penicillium marneffei infection is alarming in HIV infected patients living in endemic areas. Diagnosis relies on direct examination of the specimens and confirmation by culture. Treatment regimens include systemic amphotericin B or itraconazole followed by long-term prophylaxis. Treatment outcome depends on the immune status of the patient.