Tinea

Overview

• Definition: Tinea (ringworm) is a superficial fungal infection caused by dermatophytes affecting the skin, scalp or nails

• Common species: Trichophyton, Microsporum, and Epidermophyton

• Typical appearance: Often presents as an annular or arcuate lesion with a scaly, well-defined edge and central clearing, and can be itchy or inflamed

Clinical presentations

1. Tinea pedis (feet)

   • Most common in adults

   • May present with maceration in the toe webs, small vesicles, or diffuse scaling on the soles

   • Often associated with tinea of the groin (tinea cruris) and can spread to the toenails

2. Tinea cruris (groin)

   • Common in adult males

   • Usually a well-demarcated, erythematous rash in the groin area

   • Can spread to the upper thighs or buttocks

3. Tinea corporis (trunk, limbs, face)

   • Presents as annular, itchy lesions on non-hairy skin

   • Can be more inflammatory if caused by animal-derived dermatophytes

   • Often referred to as “ringworm” on the body

4. Tinea manus (hands)

   • Less common than tinea pedis

   • May feature diffuse scaling on the palms or ring-shaped lesions on the dorsum of the hands

   • Often unilateral

5. Tinea capitis (scalp)

   • Primarily in children

   • Presents with patchy hair loss, scaling, and sometimes the “black dot” sign (broken hairs)

   • The severe inflammatory form, kerion, appears as a boggy, painful, pustular mass

6. Onychomycosis (nails)

   • Tinea of the nails

   • Involves thickening, brittleness, and discolouration of nails

   • Requires separate management from skin-based tinea

Differential diagnoses

• Eczema (dermatitis): Tinea lesions often have a sharper border with central clearing

• Pityriasis rosea: Typically presents with a herald patch and follows skin cleavage lines

• Granuloma annulare: Ring-like lesions that lack significant scale or itch

• Psoriasis: Usually thicker scale, can involve nail pitting, and is often less annular

• Candidiasis: Common in moist skin folds, does not typically produce a true ring pattern

Diagnosis

1. Clinical suspicionCharacteristic annular, scaly lesion, but can be confused with dermatitis, psoriasis or other skin conditions

2. Microscopy and culture

   • Skin scrapings, nail clippings, subungual debris, or plucked hairs (for tinea capitis)

   • Confirm diagnosis before oral therapy or if clinical uncertainty exists before topical treatment

   • Wood lamp examination helps with species like Microsporum canis

Indications for topical vs oral therapy

• Topical therapy

  • Recent onset, localised tinea affecting trunk, groin, limbs, or interdigital spaces

  • Not indicated for hyperkeratotic, widespread, or scalp infection

• Oral therapy

  • Widespread or resistant tinea

  • Hyperkeratotic, vesicular, or pustular forms

  • Tinea capitis or involvement of palms/soles

  • Recurrence after topical therapy

  • Tinea incognito (misuse of topical steroids)

Management

Topical therapy

Suitable for mild, localised tinea on trunk, groin, limbs, or interdigital spaces

• Terbinafine 1% cream or gel once or twice daily for 1–2 weeks

• Azoles (bifonazole 1%, clotrimazole 1%, econazole 1%, ketoconazole 2%, miconazole 2%) typically once or twice daily for 2–4 weeks

Key points

• Combination steroid–antifungal creams can relieve inflammation but do not improve cure rates

• Advise patients to keep feet dry, change socks often, and let shoes dry thoroughly

• If there is no improvement, re-check diagnosis or consider oral therapy

Oral therapy (non-scalp, non-nail tinea)

Indicated for extensive, hyperkeratotic, or unresponsive infection

1. Terbinafine 250 mg daily (adult)

   • 2 weeks

   • Child <20 kg: 62.5 mg once daily; 20–40 kg: 125 mg once daily

2. Fluconazole 150 mg weekly (adult)

   • 6 weeks total

3. Itraconazole

   • Sporanox capsule: 100 mg once daily for 2 weeks (tinea cruris/corporis) or 4 weeks (tinea pedis)

   • Lozanoc capsule: 50 mg once daily (same duration)

4. Griseofulvin 500 mg daily

   • Child: 10 mg/kg (max 500 mg) daily

   • 8–12 weeks, cheaper but less effective

Tinea capitis (scalp)

• Common in children, topical agents alone are ineffective

• Empirical regimen (frequently for Trichophyton): Terbinafine 250 mg daily for 4 weeks (dose adjusted by weight in children)

• Microsporum species: Griseofulvin 20 mg/kg daily (up to 500 mg) for 6–8 weeks

Alternatives

• Itraconazole (Sporanox liquid) 5 mg/kg daily (up to 200 mg) for 4 weeks

• Fluconazole 6 mg/kg daily (up to 400 mg) for 3–6 weeks, or 8 mg/kg weekly (up to 800 mg) for 8–12 weeks in children

Kerion

• Urgent referral recommended

• Often superinfected; manage with oral antifungals and possible adjunct antibiotics

Follow-up

• Repeat culture at end of treatment

• If culture is negative and scalp is clinically normal, stop treatment

• If culture remains positive, continue therapy and repeat every 4–6 weeks until clear