What is the diagnosis and treatment for Tinea (Ringworm)?

From the Guidelines

For the treatment of ringworm, specifically tinea capitis, oral therapy with either griseofulvin or terbinafine is generally indicated to achieve both clinical and mycological cure, with the choice of systemic therapy directed by the causative dermatophyte and/or local epidemiology 1. The treatment approach should be based on the severity of the infection and the presence of cardinal clinical signs such as scale, lymphadenopathy, or alopecia.

• In cases where a kerion is present or one or more of the cardinal clinical signs is evident, it is reasonable to commence treatment while awaiting confirmatory mycology 1.
• The dosage of griseofulvin or terbinafine should be determined by the patient's body weight, with griseofulvin dosed at 15-20 mg/kg/day for 6-8 weeks for patients under 50 kg, and terbinafine dosed at 250 mg/day for 2-4 weeks for patients over 40 kg 1.
• Topical therapy alone is not recommended for the treatment of tinea capitis, as it is unlikely to achieve a mycological cure 1.
• In cases of treatment failure, considerations should include lack of compliance, suboptimal absorption of the drug, relative insensitivity of the organism, and reinfection, with second-line therapy options including itraconazole 1.
• Additional measures such as keeping the affected area clean and dry, avoiding sharing personal items, and washing bedding and clothes in hot water can help prevent reinfection 1.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION Accurate diagnosis of the infecting organism is essential. Identification should be made either by direct microscopic examination of a mounting of infected tissue in a solution of potassium hydroxide or by culture on an appropriate medium Medication must be continued until the infecting organism is completely eradicated as indicated by appropriate clinical or laboratory examination. Representative treatment periods are tinea capitis, 4 to 6 weeks; tinea corporis, 2 to 4 weeks; tinea pedis, 4 to 8 weeks; INDICATIONS AND USAGE Griseofulvin oral suspension, USP is indicated for the treatment of dermatophyte infections of the skin not adequately treated by topical therapy, hair and nails, namely: Tinea corporis Tinea pedis Tinea cruris Tinea barbae Tinea capitis Tinea unguium when caused by one or more of the following species of fungi: Ringworm is also known as Tinea.

• The treatment for Tinea corporis (ringworm of the body) with griseofulvin is 2 to 4 weeks 2.
• The diagnosis should be confirmed by laboratory testing, such as KOH preparation or fungal culture 2.
• Griseofulvin is indicated for the treatment of dermatophyte infections, including Tinea corporis 2.

From the Research

Definition and Treatment of Ringworm

• Ringworm, also known as tinea corporis, is a common fungal infection that mimics many other annular lesions 3.
• The standard treatment of tinea corporis is with topical antifungals, but systemic antifungal treatment is indicated if the lesion is multiple, extensive, deep, recurrent, chronic, or unresponsive to topical antifungal treatment 3.

Systemic Antifungal Treatment

• Two medications, griseofulvin and terbinafine, are FDA-approved to treat tinea capitis, a fungal infection involving the hair shaft of the scalp, which is commonly referred to as ringworm 4.
• Griseofulvin and terbinafine are effective in the treatment of tinea imbricata, with significant remission achieved in these groups lasting up to 8 weeks after cessation of therapy 5.
• However, a study found limited effectiveness of four oral antifungal drugs, including fluconazole, griseofulvin, itraconazole, and terbinafine, in the treatment of chronic and chronic relapsing dermatophytosis in India 6.

Topical Antifungal Treatment

• A mixed-treatment comparison meta-analysis found no statistically significant differences among topical antifungals concerning the outcome of mycologic cure at the end of treatment 7.
• However, butenafine hydrochloride and terbinafine hydrochloride were significantly more efficacious than clotrimazole, oxiconazole nitrate, and sertaconazole nitrate in achieving sustained cure 7.

Diagnosis of Ringworm

• The diagnosis of tinea corporis is usually clinical and should pose no problem to the physician provided the lesion is typical 3.
• However, many clinical variants of tinea corporis exist, rendering the diagnosis difficult, especially with prior use of medications such as calcineurin inhibitors or corticosteroids 3.
• Dermoscopy is a useful and non-invasive diagnostic tool, and fungal culture is the gold standard to diagnose dermatophytosis, especially if the diagnosis is in doubt and results of other tests are inconclusive or the infection is widespread, severe, or resistant to treatment 3.