My Last post made all of you clear about superficial fungal infections like tinea nigra, tinea versicolor and the black and white piedra.
As an effort to explain the mycoses..this article will be dedicated to discussion on cutaneous mycoses

What are cutaneuos mycoses?

These are fungal infections of skin, hair and nails whose clinical manifestation is termed as 'ringworm'. They affect humans, other mammals and birds and are caused by a group of fungi called dermatophytes.

Why is it called ringworm?

The lesions produced often look circular, hence the name. They are also called tinea because of the serpentine and annular lesions resembling a worm burrowing at the margin

What fungi cause ringworm?

These three fungi are differentiated on the basis of nature of macroconidia. they possess

Trichophyton species:

• sparse thin walled macroconidia
• affect hair and nails

Microsporum species:

• multicellular and spindle shaped macroconidia
• affect hair and skin

Epidermophyton:

• club shaped macroconidia..
• affect skin and nails

Morphology of dermatophytes:

• lesions present hyphae and arthrospores
• culture exhibit septate hyphae and asexual spores

What are the clinical forms of ringworm?

They are:

Tinea capitis: affecting scalp and hair

Tinea corporis: affecting skin

Tinea crusis: affecting groin, perineum

Tinea pedis: affecting foot;Athlete's foot

Tinea Unguim : affecting nails

Species of Dermatophytes

T.concentricum, T. rubrum, T. tonsurans

M. canis, M.nanum

E.floccosum

Epidemiological classification of dermatophytes:

On the basis of habitat they can be classified into:

• Antrophilic: infecting humans
• Zoophilic: infecting dogs, cat,cows
• Geophilic: infecting soil associated organisms

Treatment of ringworms:

• for mild cases: Clotrimazole or Imidazole
• for severe infections: Griseofulvin for 4-6 weeks