Skip to Main Content

TINEA (DERMATOPHYTE) INFECTIONS

Etiology: Dermatophytes digest and invade keratin and may infect skin, nails, and hair; incubation = 1—3 wk. Trichophyton, Microsporum, Epidermophyton species commonly involved. Human-to-human (anthropophilic), animal-to-human (zoophilic; intense inflammation), or soil-to- human (geophilic; moderate inflammation) spread.

Risk Factors: Hot, humid environments, sweating or maceration of the skin, occlusive footwear, diabetes mellitus, immunosuppression (e.g., AIDS).

History:Asymptomatic; occasionally mild pruritus.

Physical: Scalp hair and general body surfaces mostly affected during childhood; hand, foot, or nail infections are more common after puberty.

  • Immunologic response to a dermatophyte infection may result in a dermatophytid or “id” reaction: Vesicular eruption on acral surfaces, especially the palms.

Investigations:Skin scraping analysis with KOH prep—Septate hyphae branching at various angles are seen; fungal culture (~4 wk to ID dermatophyte species); biopsy—PAS or GMS stain can reveal presence of fungal elements.

DDx: Eczema, granuloma annulare, psoriasis.

Tinea Corporis

Affects trunk and extremities: Erythematous annular scaly patches with “active border”, central clearing; #1 cause = T. rubrum.

Tinea Pedis

  1. Interdigital type: Macerated, scaly plaques in toe web spaces, can be portal of entry for cellulitis of the foot, especially in diabetics. (Tip: in recurrent leg cellulitis, look for tinea pedis!)

  2. “Moccasin” type: Dryness, scaling and erythema of the plantar and/or lateral foot.

  3. Vesicular type: vesicles, pustules, or bullae on the feet.

    • “One hand, two feet disease”: Common clinical presentation of tinea pedis involving one hand and both feet.

Tinea Cruris

Inner thighs and inguinal folds; tinea faciei: face; tinea manuum: hands; tinea barbae: beard area.

Tinea Capitis

Alopecia with scale, kerion (boggy mass), or discrete pustules; very contagious.

Tinea Unguium/Onychomycosis

See onychomycosis section.

Management

Patient education: Avoid factors which predispose to infection, absorbent powders in intertriginous areas, e.g., for tinea pedis— shower-shoes in public facilities.

Topical antifungals for tinea corporis/cruris/pedis (unless lesions are extensive): Terbinafine, ciclopirox, clotrimazole, ketoconazole applied qd or bid × 3 wk, or continue 1 wk until after resolution of lesions.

Systemic antifungals for tinea capitis.

  1. Terbinafine (Lamisil) <20 kg = 62.5 mg po qd, 20—40 kg = 125 mg po qd, >40 mg = 250 mg po qd × 2—4 wk.

  2. Micronized ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.