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

From the Guidelines

The diagnosis of Tinea (Ringworm) involves laboratory confirmation through microscopy and culture of scalp lesions, and treatment should commence with oral therapy, such as griseofulvin or terbinafine, as topical therapy alone is not recommended. The choice of systemic therapy should be directed by the causative dermatophyte and/or local epidemiology 1.

Key Considerations

• The diagnosis of Tinea capitis should involve sampling of scalp lesions via scalpel scraping, hair pluck, brush, or swab, with all specimens processed for microscopy and culture 1.
• Treatment should not be delayed if a kerion or cardinal clinical signs are present, and oral therapy is generally indicated to achieve both clinical and mycological cure 1.
• Griseofulvin and terbinafine are the most widely used first-line treatments, with terbinafine being more efficacious against Trichophyton species and griseofulvin more effective against Microsporum species 1.

Treatment Options

• Griseofulvin dose by body weight:
  • < 50 kg: 15–20 mg kg−1 per day for 6–8 weeks

  • 50 kg: 1 g per day for 6–8 weeks

• Terbinafine dose by body weight:
  • < 20 kg: 625 mg per day for 2–4 weeks
  • 20–40 kg: 125 mg per day for 2–4 weeks

  • 40 kg: 250 mg per day for 2–4 weeks

Additional Measures

• Children receiving appropriate therapy should be allowed to attend school or nursery 1.
• Index cases due to T. tonsurans warrant screening of all family members and close contacts and treatment for those positive cases 1.
• In asymptomatic carriers with a high spore load, systemic treatment is generally justified 1.
• The end point of treatment is mycological rather than clinical cure, and repeat mycology sampling is recommended until mycological clearance is achieved 1.

Prevention

• Avoiding skin-to-skin contact with people known to have lesions, not sharing towels and other fomites, and limiting exposure to swimming pools that have recently been associated with known outbreaks can help prevent the spread of Tinea infections 1.

From the FDA Drug Label

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 Prior to therapy, a dermatophyte should be identified as responsible for the infection Prior to initiating treatment, appropriate specimens for laboratory testing (KOH preparation, fungal culture, or nail biopsy) should be obtained to confirm the diagnosis

The diagnosis of Tinea (Ringworm) involves accurate identification of the infecting organism through:

• Direct microscopic examination
• Culture on an appropriate medium
• Laboratory testing (KOH preparation, fungal culture, or nail biopsy)

The treatment for Tinea (Ringworm) is griseofulvin (PO), with the following dosage recommendations:

• Adults: 0.5 g daily
• Pediatric patients (older than 2 years): 10 mg/kg daily
• Treatment periods vary by type of infection:
  • Tinea capitis: 4 to 6 weeks
  • Tinea corporis: 2 to 4 weeks
  • Tinea pedis: 4 to 8 weeks
  • Tinea unguium: at least 4 months (fingernails) or 6 months (toenails) 2 2

From the Research

Diagnosis of Tinea (Ringworm)

• Diagnosis is usually based on history and clinical appearance plus direct microscopy of a potassium hydroxide preparation 3
• Culture or histologic examination is rarely required for diagnosis 3
• Accurate diagnosis is necessary for effective treatment 3

Treatment of Tinea (Ringworm)

• Topical therapy is generally successful unless the infection covers an extensive area or is resistant to initial therapy 3
• Systemic therapy may be required for extensive or resistant infections 3
• Treatment requires attention to exacerbating factors such as skin moisture and choosing an appropriate antifungal agent 3
• Tinea corporis and cruris infections are usually treated for two weeks, while tinea pedis is treated for four weeks with an azole or for one to two weeks with allylamine medication 3
• Treatment should continue for at least one week after clinical clearing of infection 3
• Newer medications require fewer applications and a shorter duration of use 3

Treatment Options for Tinea Capitis

• Griseofulvin is approved for therapy by regulatory agencies, but newer antifungal agents such as itraconazole, fluconazole, and terbinafine have broadened the therapeutic armamentarium 4
• Itraconazole and terbinafine seem to be equally or more effective in treatment of tinea capitis within a shorter period of time than griseofulvin 4
• Fluconazole is probably also effective for this indication, although supporting data is limited 4
• Griseofulvin given for 6 weeks is similar in efficacy to terbinafine, itraconazole, and fluconazole given for 2-3 weeks 5
• Terbinafine (Lamisil Granules) is FDA-approved to treat tinea capitis, with treatment requiring 6 weeks 6

Treatment of Tinea Pedis

• Topical therapy is an accepted and successful method for the management of this condition 7
• Terbinafine has been shown to give equally good results when applied once or twice daily for 1-2 weeks 7
• A cure rate of 78% was achieved in patients with tinea pedis after a single application of 1% terbinafine cream 7
• Topical terbinafine has also been compared to clotrimazole for the treatment of tinea pedis, with terbinafine 1% cream applied twice daily for 1 week being significantly superior to a 4-week course of clotrimazole 1% cream 7