What Is the Treatment for Tinea Corporis?

Tinea corporis is a superficial fungal infection of the skin that can affect any area of the body, except for the hands, feet, scalp, face, beard, groin, and nails. Children and young people are most frequently affected by tinea corporis.

It is frequently referred to as “ringworm” because of the distinctive ring-shaped lesions that it causes. The condition may cause single, multiple, or merging lesions of various sizes. Sometimes, pustules or vesicles can form on the active edge.

Dermatophyte fungi of Trichophyton and Microsporum are the main causes of tinea corporis. 

T. rubrum, an anthropophilic species, is the most common source of tinea corporis globally, including in New Zealand. Other species that can cause tinea corporis include:

• T. interdigitale
• T. tonsurans (skin-to-skin contact or after tinea capitis)
• M. canis (cats and dogs)
• Less frequently, other zoonotic species, such as T. verrucosum (cattle), T. equinum (horses), and T. erinacei (hedgehogs)

Tinea corporis spreads through the release of fungus spores from infected skin. Transmission is aided by a warm, moist environment and through sharing of fomites through clothing, towels, and bedding. The infection can spread in the following ways:

• Human to human: Direct skin-to-skin contact with an infected person
• Animal to human: Direct contact with an infected animal (petting or grooming dogs or cats)
• Object to human: Contact with objects or surfaces, such as clothing, towels, beds, linens, combs, and brushes, that an infected person or animal has recently touched 
• Soil to human: Only continuous contact with extremely contaminated soil would likely result in infection

Symptoms of tinea corporis infection include:

• A ring-shaped, itchy area that commonly appears on the buttocks, torso, arms, and legs
• Inside the ring, there may be a clear or scaly area with a few bumps that range in color from red (on white skin) to reddish, purple, brown, or grey (on black and brown skin)
• Expanding or slightly elevated rings
• Overlapping rings

Possible complications of tinea corporis infection include the following:

• Tinea corporis infection can spread to other areas of the skin.
• People with immunosuppressed conditions, such as HIV/AIDS, may exhibit signs of disseminated infection.
• Children with tinea corporis and atopic dermatitis frequently get secondary bacterial infections caused by Staph aureus.
• Dermatophytid reactions are allergic rashes that can be brought on by an inflammatory fungal infection.
• T. rubrum infection causes chronic dermatophytosis, involving at least four different body sites, with a protracted variable course and recurrence despite treatment.

Treatment for ringworm varies depending on the location and severity of the tinea infection. General measures to treat tinea infection include the following:

• Keeping your skin clean and dry
• Wearing loose-fitting, lightweight clothing during hot or humid weather
• Avoiding sharing bedding or towels
• Avoiding direct contact with infected people
• Checking family members and pets for signs of infection

Topical therapy is effective for most people with tinea corporis, tinea cruris, and tinea pedis. Terbinafine 1% cream applied 1-2 times daily for 1-2 weeks is advised as the first-line topical therapy.

Oral therapy should be considered in the following situations:

• Significant tinea on the skin
• Ineffective topical therapy
• Immunocompromised people

Terbinafine 250 mg once daily is advised as a first-line oral treatment for adults. When administered to healthy people, terbinafine is often safe and does not require periodic blood testing. People with moderate to severe chronic kidney disease (creatinine clearance less than 50 mL/min) must reduce their dosage, whereas those with significant liver impairment should not take it.