Sean Klepper M.D.
Artur Zembowicz M.D....
- Common cutaneous or ungual infection caused by members of three genera of fungi: Epidermophyton, Microsporum and Trichophyton.
- Clinically named according to the site of infection:
- Tinea capitis: Infection of the scalp. Varies from mild erythema to inflammatory lesions with pustules and folliculitis
- Tinea corporis: Infection of glaborous skin. Also known as "ringworm." Presents as an erythematous, centrifugally growing annular lesion with a peripheral scale.
- Tinea barbae: Infection of the beard area
- Tinea cruris: Infection of the inguinal area. Also known as "jock itch." Almost exclusively seen in males.
- Tinea pedis: Infection of the foot. Also known as "athlete's foot." There are three types: plantar moccasin-like, interdigital and vesiculobullous.
- Tinea manuum: Infection of the hand. Often coexists with tinea pedis. Most often presents as hyperkeratosis with prominent flexural creases.
- Tinea unguium: Infection of the nails. Also known as onychomycosis.
- The histologic findings are highly variable.
- Epidermal changes may include:
- Neutrophilic infiltrate
- Compact orthokeratosis
- "Sandwich sign": hyphae "sandwiched" between an upper normal-appearing stratum corneum and a lower layer of compact orthokeratosis or parakeratosis
- Mild spongiosis (Significant spongiosis and vesiculation may be present on acral skin.)
- Acanthosis in chronic lesions
- Dermal changes may include:
- Mild superficial edema
- A mild to moderate perivascular infiltrate of lymphocytes and occasional neutrophils and eosinophils
- Fungal forms in the form of yeasts and bizarre hyphae are best appreciated on PAS or GMS stains.