Tinea Infections

INTRODUCTION

Tinea, or ringworm infections, are caused mainly by three major classes of dermatophytic organisms. It is most useful to perform skin scrapings and microscopy to look for encroaching septate hyphae. Confirm the diagnosis by fungal culture.

TINEA CAPITIS

Clinical features

• Usually in children

• Patches of partial alopecia

• Scaly patches

• Small broken-off hair shafts

• Hairs may fluoresce yellow–green with Wood’s light (about 60%)

Treatment (Topical is ineffective, commence with oral regimen)

• Terbinafine (o)

  • – adults: 250 mg/d, 4 wks or until clinical resolution

• Griseofulvin (o)

  • – adults: 500 mg/d

  • – children: 10 mg/kg/d (max. 500 mg) 6–12 wk course

Also: Take hair plucking and scale for culture.

TINEA CRURIS (JOCK ITCH)

• Common in young men, usually athletes

• Scaling, esp. at margin

• Well-defined border

Diagnostic aids

• Skin scrapings should be taken from the scaly area for preparation for microscopy.

• Wood’s light may help the diagnosis, particularly if erythrasma is suspected.

Treatment

• Dry skinfolds fastidiously

• Apply terbinafine 1% cream or gel/d–bd for 7–14 d or an imidazole topical preparation (e.g. clotrimazole 1% or miconazole 2% cream)

• When almost healed, apply tolnaftate dusting powder bd for 3–4 wks

• If itch severe: add 1% hydrocortisone cream

• For persistent or recurrent eruption, use oral terbinafine for 2–4 wks or oral griseofulvin for 6–8 wks

TINEA PEDIS (ATHLETE’S FOOT)

Symptoms Commonest symptoms are itchiness and foot odour. There is scaling, maceration and fissuring of the skin between the fourth and fifth toes and also third and fourth toes.

Management

• Patient education

• Keep feet clean and dry

• Use antifungal powder between toes after drying

• Wear socks of natural absorbent fibres—cotton and wool (avoid synthetics)

• Wear open sandals and shoes with porous soles and uppers (if possible)

• Use thongs in public showers

Treatment As for tinea cruris with preference for terbinafine 1% cream d–bd for 1–2 wks (apply after drying) and review. If severe and spreading (take scrapings), use griseofulvin 500 mg or terbinafine 250 mg (o) d for up to 6 weeks.

TINEA OF TOENAILS AND FINGERNAILS (TINEA UNGUIUM)

• Usually associated with tinea pedis

• Nails show white spots; may be yellow and crumbling

• Starts at the edge of periphery and spreads towards base

• Diagnosis is by microscopy and culture of clippings/scrapings of the affected nail

Treatment

If the patient requests treatment, oral options include:

• Terbinafine 250 mg (o)/d

  • – fingernails 6 wks

  • – toenails 12 wks

• Itraconazole (Sporanox) 200 mg (o) bd—as pulse therapy: 1 wk on, 3 wks off × 2 fingernails, × 3 toenails

Topical:

• Poor evidence ...