Test : Skin fungus culture
Indications : The test is ordered for the following reasons:
• Fungal infection is suspected in the skin, nails or hair
• Skin rash, sore or ulcer is present
Skin scrapings, exudates, hair, nail clippings, whole nail, hair and debris under nail form the samples for the test. A cotton swab may be used to collect a skin sample from a rash or wound on the skin. Sometimes a small skin sample is taken for the culture. No prior preparation is required.
The sample is streaked onto a culture dish containing appropriate growth medium that promotes fungal growth. It may take a few days to grow in culture before diagnosis can be established.
Physiology : Skin fungus culture is a laboratory test that is carried out to diagnose
skin infections caused by fungi. The kingdom of fungi include microorganisms such as yeasts and molds, and are abundant worldwide.
Most
fungal infections begin on the skin or in the lungs. Fungus such as Candida sp, may colonize skin. Signs of Candida infection include bright erythema, fragile papulopustules, and satellite lesions. Fungal infections occur when a person has a weak immune system, or when on antibiotics.
Anti-fungal medications can be applied directly on the affected area. In serious cases, medications may have to be taken orally.
Normal Range : No growth
Interpretation : Normal
Negative - Only normal flora seen. No fungal growth from the skin sample observed
Abnormal
Positive - Fungal growth observed in culture indicating any of the following:
• Superficial mycoses - Piedra, Tinea nigra, Tinea versicolor
• Dermatomycoses - Oncyhomycosis, Tinea captis, Tinea corporis,
Tinea pedis, Tinea cruris
• Candididasis - Thrush, Diaper dermatitis, Paroncyhia, Congenital
candidiasis, mucocutaneous candididasis.
Sample : Skin scrapings, exudates, nail clippings, whole nail, debris, under nail, hair.
Test Method : Aerobic culture on selective media.
References :
1. http://www.nlm.nih.gov/medlineplus/ency/article/003762.htm
2. http://www.nlm.nih.gov/medlineplus/fungalinfections.html