dermatophytoses

Following are commonly seen Dermatophytoses

1. Tinea pedis 

(Athlete's food)

Infection in between toes, spread to nail, become yellow and brittle.

2. Tinea corporis

Ring worm 

Lesion appear angular ring with scaly center. Site of infection usually inflamed and vesiculated.

3. Tinea captitis

Producing small, scaling 

Scalp ring worm

4. Tinea unguium

Nails are thickened, discoloured and brittle 

5. Tinea cruris

(Jock itch)

Produce infection in skin of genitals area, moist groin area spread from upper thigh to genitalia.

Laboratory pathogenesis

Specimen collection

Infected hair, nail

KOH preparation

Direct microscopic examination show spores surrounding hair.

Culture

Culture on Sabouraud's dextrose agar.

Culture media are incubated at 25-30 degree Celsius for 3 weeks.

Indentification of dermatophytes is based on;

Colony morphology

Pigment production

Microconidia and macroconidia 

Colony characteristics

White to creamy, cottony growth and yellow colonies. White to tan coloured colonies, powdery colonies.

Treatment

Topical antifungal agent are generally used for treatment.

Oral griseofulvin or miconazole cream are effective drug.