Trichophyton

Trichophyton rubrum var. rodhaini

Trichophyton is a genus of fungi in the family Arthrodermataceae. This genus is known for containing species that cause dermatophytosis, commonly referred to as ringworm, in humans and animals. The fungi are keratinophilic, meaning they have the ability to invade and digest keratinized tissues such as skin, hair, and nails.

Characteristics

Trichophyton species are characterized by their ability to produce both macroconidia and microconidia. The macroconidia are typically smooth-walled, pencil-shaped, and multicellular, while the microconidia are smaller, spherical to pyriform, and unicellular. These fungi grow well on Sabouraud agar and exhibit a range of colony morphologies, from fluffy to granular.

Pathogenicity

Trichophyton species are responsible for a variety of cutaneous mycoses. The most common infections include:

• Tinea pedis (athlete's foot)
• Tinea corporis (ringworm of the body)
• Tinea capitis (scalp ringworm)
• Tinea unguium (onychomycosis or nail infection)

These infections are typically superficial, affecting the stratum corneum of the skin, but can cause significant discomfort and are highly contagious.

Common Species

Several species of Trichophyton are of medical importance:

• Trichophyton rubrum - The most common cause of athlete's foot, jock itch, and nail infections.
• Trichophyton mentagrophytes - Often associated with animal infections and can cause similar conditions in humans.
• Trichophyton tonsurans - A common cause of tinea capitis, especially in children.

Diagnosis and Treatment

Diagnosis of Trichophyton infections is typically made through clinical examination and confirmed by laboratory tests such as KOH preparation, culture, and sometimes PCR for species identification. Treatment involves the use of topical or oral antifungal medications, such as terbinafine, itraconazole, or griseofulvin.

Related Pages

• Dermatophyte
• Fungal infection
• Antifungal medication