How to treat ringworm

Early recognition and proper management of ringworm are essential to relieve symptoms, prevent transmission, and avoid complications such as secondary bacterial infection or scarring alopecia. GPs are usually the first line of treatment.

What is ringworm?

Despite its name, ringworm is not caused by a worm. It is a superficial fungal infection. The condition develops as a consequence of dermatophyte fungi growth, mainly Trichophyton, Microsporum, and Epidermophyton species. These are known to infect keratinised tissues such as the skin, hair, and nails.

Diagnosing ringworm in primary care

Diagnosis of ringworm is primarily based on the clinical presentation of the disease. The typical features include:

• Annular, scaly lesions with raised erythematous borders and central clearing
• Itching or mild burning

The presentation pattern depends largely on the location. We can differentiate:

• Tinea corporis (trunk and limbs)
• Tinea cruris (groin and inner thighs)
• Tinea pedis (“athlete’s foot”)
• Tinea capitis (scalp, often with patchy hair loss)
• Tinea unguium or onychomycosis (thickened and discoloured nails)

While diagnosis is clinical, confirmatory testing is still recommended in atypical, recurrent, or resistant cases. Testing may include:

• KOH preparation: Scrape scales from lesion edges and examine for hyphae.
• Fungal culture: For resistant, recurrent, or uncertain cases.
• Wood’s lamp: Useful for Microsporum infections (fluoresce green).

Treatment of ringworm

It is vital to identify and treat predisposing factors, such as excessive sweating, tight clothing, contact sports, and immunosuppression.

Also, it is important to avoid treating severe inflammation with topical corticosteroids unless they are combined with antifungals (even then only short term). This is because steroid monotherapy can worsen the infection (“tinea incognito”). Last but not least, educate patients on hygiene and preventing spread.

Topical therapy (first-line therapy for most cases)

Use topical antifungals, once or twice daily to cover the lesion and a two centimetres margin around it for two to four weeks and one week after resolution. Effective antifungal options include:

• Azoles: Clotrimazole, Miconazole, Ketoconazole
• Allylamines: Terbinafine, Naftifine, Butenafine (often more effective and shorter duration)
• Ciclopirox (alternative for resistant or mixed infections)

Topical antifungal therapy is usually enough to treat single, small lesions of tinea corporis, tinea cruris, or tinea pedis (interdigital type) in immunocompetent individuals with no nail or hair involvement.

Systemic therapy

Indications for systemic therapy are:

• Scalp involvement (tinea capitis)
• Nail involvement (onychomycosis)
• Widespread, chronic, or recurrent infection
• Failure of topical therapy after four weeks
• Immunocompromised patients

In such cases, the use of oral antifungals is recommended. Here is an overview of appropriate systemic first-line therapies with typical adult doses (TAD) and duration of treatment included:

Alternatives include Itraconazole 100–200 mg daily (same duration) or Fluconazole 150 mg weekly for up to three months.

Supportive and preventive measures

It is essential to educate primary care patients about the supportive and preventive measures, such as:

• Keeping affected areas dry and well-ventilated
• Changing socks and underwear daily and avoiding tight-fitting clothing
• Using antifungal powders for recurrent tinea pedis or cruris
• Avoiding sharing towels, shoes, combs, or hats
• Disinfecting personal items (hairbrushes, nail tools, footwear)
• Treating household contacts or pets if recurrent infections occur

When to refer

Refer to dermatology if:

• Diagnosis is uncertain
• Recurrent or chronic infection despite adequate therapy
• Widespread disease or immunocompromised host
• Severe tinea capitis (kerion formation) or scarring alopecia
• Onychomycosis resistant to standard treatment

Ringworm is a common and easily recognisable condition that can be effectively managed in primary care with appropriate use of topical or systemic antifungal therapy. Early diagnosis, proper patient education, and preventive hygiene are key to successful outcomes and reduced recurrence.

– Dr Rosmy De Barros

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References

• Degreef, H. (2008). Clinical forms of dermatophytosis (ringworm infection). Mycopathologia, 166(5), 257-265.
• Saha, M., Naskar, M. K., & Chatterji, B. N. (2021). Human skin ringworm detection using wavelet and curvelet transforms: a comparative study. International Journal of Computational Vision and Robotics, 11(3), 245-263.
• Oklota, C. A., & Brodell, R. T. (2004). Uncovering tinea incognito: Topical corticosteroids can mask typical features of ringworm. Postgraduate medicine, 116(1), 65-66.
• Jain, N., & Sharma, M. (2003). Broad spectrum antimycotic drug for the treatment of ringworm infection in human beings. Current science, 85(1), 30-34.
• Emanghe, U. E., Imalele, E. E., Ogban, G. I., & Owai, P. A. (2024). Awareness and Knowledge of Scabies and Ringworm among Parents of School-age Children in Calabar, Cross River State, Nigeria: Implications for Prevention of Superficial Skin Infestations. Annals of African Medicine, 23(1), 62-69.