Dermatophytes: Introduction, Infection and Its Laboratory Diagnosis
Introduction of Dermatophytes
Dermatophytes are a common label for a group of three types of fungi i.e. Trichophyton, Microsporum, and Epidermophyton that commonly cause skin, nail, and hair disease in our body.
Dermatophytes are the causative agent of ringworm that infects only superficial keratinized tissues and infection of skin, hair, and nail. They are a group of three genera.
a. Trichophyton ( skin, hair, and nail) b. Microsporum (Hair and skin) c. Epidermophyton (skin and nail) Causative agents of ringworm do not involve in living tissue. Spores of these fungi may live for a longer period in soil. Direct contact with soil causes us infection. It can also spread through contact with an infected person. The infection is commonly spread among children and by sharing items that may dirty.
They are keratinophilic fungi that infect keratinized tissues causing diseases known as dermatophytoses. Ringworm or tinea is synonyms for each other. It is a fungal infection of the skin. The name is “ringworm” but the infection is due to a fungus, not a worm. The infection initially presents with red patches on affected areas of the skin and later spreads to other parts of the body. It can affect anyone. The infection may affect the skin of the scalp, groin, beard, feet, or other parts of the body.
Types Of Ringworm
Clinically ringworm is of the following types depending on the site of the body involvement- e.g. Tinea axillaries: axilla Tinea barbae: beard area Tinea corporis: Non-hair skin Tinea capitis: The hair and scalp of the body often appear as patches with the characteristic round “ring” shape. Tinea corporis: in the groin Tinea pedis: foot (Athlete’s foot) Tinea pedis is common in people who go barefoot in public places where the infection can spread, for e.g. locker rooms, showers, swimming pools, etc.
Laboratory Diagnosis of dermatophytes
Your dermatologist will diagnose ringworm due to dermatophytes by examining your skin and possibly using a black light to view your skin in the affected area. The fungus will fluoresce under black light. In case of infection, the areas of the skin where the fungus is located will glow. For confirmatory diagnosis your dermatologist will request the following tests: