Tinea Corporis

Tinea corporis is a superficial dermatophyte infection of the glabrous (non-hairy) skin of the body. It commonly affects the arms, legs, trunk, and neck, but may occur on any part of the body except the scalp, groin, palms, and soles.

It is commonly referred to as “ringworm” or Ringworm of the Body because of its characteristic ring-shaped appearance.

The condition is contagious and occurs worldwide, especially in warm and humid climates.

Causative Organisms

Tinea corporis is caused by dermatophytes belonging to:

• Trichophyton species (most common)

• Microsporum species

• Epidermophyton floccosum

Sources of Infection

Epidemiology & Risk Factors

Risk Factors

• Hot and humid climate

• Excess sweating

• Poor hygiene

• Crowded living conditions

• Contact sports (wrestling)

• Immunosuppression

• Diabetes mellitus

• Sharing clothing or towels

• Close contact with infected persons or animals

Children and young adults are commonly affected.

Pathophysiology

Dermatophytes infect keratinized tissues only:

1. Fungal spores attach to stratum corneum

2. Fungi digest keratin using keratinase enzymes

3. Radial outward growth occurs

4. Central clearing develops as immune response controls infection centrally

This explains the annular ring-shaped lesion with active border.

Clinical Presentation

Classical Lesion

• Enlarging raised annular plaque

• Well-defined erythematous border

• Central clearing

• Peripheral scaling

• Itching (pruritus)

• Mild inflammation

Variations

• Multiple lesions may coalesce

• Vesicles at advancing border

• Follicular involvement (hair loss in affected area)

• Extensive lesions in immunocompromised

Inflammatory Tinea Corporis

• More erythematous

• Pustular border

• Common with zoophilic species

Diagnostic Criteria

Diagnosis is clinical when:

• Annular raised lesions

• Central clearing

• Scaling at edges

• Peripheral extension

• Itching present

• Risk factor history

Investigations

Usually not required for classic presentation.

Differential Diagnosis

• Eczema (nummular dermatitis)

• Psoriasis

• Pityriasis rosea

• Granuloma annulare

• Seborrheic dermatitis

• Cutaneous lupus

Key distinguishing feature:Active advancing scaly border with central clearing

Treatment

Important Principle

Localized disease → topical therapyExtensive/recurrent disease → systemic therapy

A. Non-Pharmacological Treatment

• Keep skin clean and dry

• Avoid tight clothing

• Do not share towels/clothes

• Wash infected clothing separately

• Treat infected pets

• Avoid scratching

• Maintain good hygiene

• Manage diabetes

B. Pharmacological Treatment

1. First-Line Topical Therapy (Localized Disease)

Benzoic Acid Compound (Whitfield’s) ointmentApply every 12 hours for up to 2 weeks

OR

Miconazole 2% creamApply thinly every 12 hoursContinue 5–7 days after lesion clears

Alternative Topical Options

• Clotrimazole 1% cream

• Ketoconazole cream

• Terbinafine cream (shorter duration)

2. Systemic Therapy (If Extensive or Refractory)

Griseofulvin (PO) for 4 weeks

Adults: 500 mg every 12 hoursChildren: 250 mg every 12 hours

Take with fatty meal.

Alternative Systemic Options

• Terbinafine oral

• Itraconazole

• Fluconazole

Systemic therapy indicated for:

• Multiple widespread lesions

• Immunocompromised patients

• Failure of topical therapy

• Follicular involvement

Complications

• Secondary bacterial infection

• Chronic recurrent infection

• Post-inflammatory hyperpigmentation

• Spread to other body parts

• Tinea incognito (due to steroid misuse)

Tinea Incognito

Occurs when:

• Topical steroids are used improperly

• Lesion loses classical ring shape

• More diffuse, less scaly

• Diagnosis becomes difficult

Important: Avoid steroid-only creams.

Prevention

• Avoid sharing personal items

• Treat infected animals

• Maintain skin dryness

• Wear breathable clothing

• Prompt treatment of early lesions

• Avoid unnecessary steroid use

• Health education in schools

• Proper hygiene in sports teams

Prognosis

• Excellent with appropriate treatment

• Recurrence common if risk factors persist

• Complete resolution usually within 2–4 weeks