Tineas

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Superficial infection caused by dermatophytes or malassetia fungi, which invade dead tissue of the skin and its appendages (stratum corneum, nails and hair). They are not very infectious but are usually recurrent.

Cause

  • Trichophyton mentagrophytes or T.rubrum

Clinical features

  • Features (and name of the infection) depend on the body part affected as in table below

BODY PART AFFECTED

FEATURES

Tinea capitis
  • Bald, scaly patches with hairs broken off when very short
  • The lesion may sometimes be inflamed with multiple pustules (pockets of pus)
  • Especially in children and immuno- suppressed

Tinea corporis (ringworm)
  • Single or multiple plaques on the face, trunk or limbs
  • Well demarcated, scaly and raised border with relatively clear centre
  • Pruritus

Tinea (or pityriasis) versicolor
  • A chronic fungal infection of large areas of skin
  • Well-defined round/oval patches
  • Pale or discolored spots on the skin, e.g., chest, back, face
  • Not scaly, but peels off when scratched
  • Rare in children, onset usually around puberty

Nails (Onycho- mycosis)
  • Thickened, discolored nails, can be white, yellow, green, or black
  • Brittle nails that break easily
Tinea pedis (Athletes foot)

 
  • White scaling usually between the 4th and 5th toes or between the 3rd and 4th toes on one foot only
  • Scales, vesicles, cracks
  • Burning or itching between toes and under foot especially when shoes and socks are removed
  • May be secondary infection

Differential diagnosis

  • Seborrhoeic dermatitis, eczema, contact dermatitis
  • Alopecia areata
  • Jiggers, hookworm, candida
  • Cellulitis, psoriasis
  • Maceration from tight footwear

Investigations

  • Scales from the active edge of the lesions are scraped off, placed in 10-20% potassium hydroxide (KOH) for 30 minutes, and examined microscopically for mycelia
  • Culture of specimen on Sabouraud’s agar

ManagementTreatment

Tinea capitis

  • Oral griseofulvin 10 mg/kg/day as single dose once daily after meals for 6 weeks
  • Do NOT treat with topical antifungal agents; they cannot get to the site of infection

Tinea corporis (ringworm)

  • Apply Whitfield’s ointment (benzoic acid + salicylic acid) 12 hourly until 2 weeks after lesions clear
  • Clotrimazole 1% cream twice a day
  • Or miconazole 2% cream 12 hourly for 2-3 weeks

If topical treatment fails

  • Griseofulvin 10 mg/kg for 3 weeks

Pityriasis versicolor

  • Apply clotrimazole cream 12 hourly until lesions disappear
  • Or miconazole 2% cream 12 hourly for 2-3 weeks

If topical treatment fails

  • Fluconazole 300 mg once weekly for 2 weeks

Nails (Onychomycosis)

  • Oral griseofulvin 10 mg/kg per day as single dose once daily after meals for 6-12 months

Tinea pedis (Athletes foot)

  • Apply clotrimazole cream 12 hourly, continue for 14 days after the lesions have healed
  • Or miconazole cream as above
  • Apply powder (not necessarily medicated) to the feet rather than to the shoes
  • For persistent or non-responsive infection, oral griseofulvin 10 mg/kg/day as single dose once daily after meals for 4-8 weeks

Note on griseofulvin:

  • Double the dose in severe infections
  • Take with fatty food
  • Do NOT use for tinea versicolor (pityriasis)
  • Advise female patient to not get pregnant while on treatment
  • Men should avoid fathering children while on treatment

Prevention and health education

  • Clean all contaminated objects, e.g., combs, brushes
  • Avoid sharing contaminated combs, towels, clothes, etc
  • Advise patient on the need to persist with the long durations of treatment to completely clear infection
  • Personal foot hygiene is important. Keep feet clean and dry. Wash socks daily
  • If patient has repeat fungal infections, refer him/her for HIV counselling and testing