Fungal Infections (Tineas)
Fungus infections are extremely common in clinical practice. Fungi are plants and like all plants they like to grow in a warm, moist place. Like flowers, there are many different fungi. In practice, fungal infections are categorized according to the area of the body involved.
- Tinea capitis (scalp)
- Tinea corporis or ringworm (body)
- Tinea cruris or jock itch (groin)
- Tinea pedis or athletes feet (feet)
- Tinea manuum (hand)
- Tinea facei (face)
- Onychomycosis (nails)
The key to diagnosis for all of these fungal infections is the KOH exam. This is the ability to find the plants under the microscope when scrapings of scale, hair or nail are soaked in KOH (potassium Hydroxide solution). If the clinical lesion has no scaling and you can’t do a KOH, it’s not a fungus infection anyway. If the KOH is positive, the diagnosis is correct and the therapy will work. If it’s negative, therapy for a fungus infection will not work. If a KOH is not done, the diagnosis is an educated guess. Embarking on an expensive course of therapy without doing a KOH exposes the patient to the risk of side effects without the likelihood of clinical benefits. This is particular true in treating nail disease.