Ringworm of the body, medically known as Tinea corporis, is a common and contagious skin infection caused by a fungus. This condition is caused by mold-like fungi called dermatophytes that live on the dead tissues of the skin, hair, and nails. Tinea corporis affects the skin on the arms, legs, trunk, or face, and it thrives in warm, moist environments. The infection is characterized by a specific appearance that helps in visual identification.
Identifying Ringworm on the Arm
Ringworm on the arm typically begins as a small patch of raised, red spots or pimples that slowly expands outward. The classic presentation is a circular or ring-shaped rash. This ring formation is the most telling visual sign of the condition.
The outer edge of the lesion is often the most distinct feature, appearing raised, scaly, and noticeably red or darker than the surrounding skin, depending on the person’s skin tone. This border may also contain small firm bumps or fluid-filled blisters. As the fungus grows and spreads outward, the center of the ring often heals or clears up, creating flatter skin inside the circle.
The rash can range in size from one centimeter to ten centimeters and is generally itchy. In some cases, the ring may not be perfectly circular, or multiple lesions may merge together, making the classic ring appearance less obvious. The skin within the ring may also be scaly, or it may darken in color due to inflammation. The infection can spread to other areas of the body or to other people if left untreated.
How Ringworm Spreads
Ringworm is highly contagious and spreads primarily through direct contact. The infection can be transmitted from person to person through skin-to-skin contact, which is common in contact sports like wrestling. The fungi can also be passed indirectly through contact with contaminated objects that can harbor fungal spores.
- Towels
- Bedding
- Clothing
- Combs
- Locker room floors
Transmission is also common from animals to humans, as pets, especially cats and dogs, are common carriers of the fungus. Touching or petting an infected animal can transfer the fungus to a person’s skin. Ringworm thrives in warm and humid conditions, which makes areas with excessive sweating or prolonged wet skin more susceptible to infection.
Treatment Options and Next Steps
Mild cases of ringworm on the arm can be treated with over-the-counter (OTC) topical antifungal medications. These products, available as creams, lotions, or ointments, contain active ingredients such as clotrimazole, miconazole, or terbinafine. Apply the cream not only to the rash itself but also to the area of skin immediately surrounding it. Continue application for the full duration recommended on the packaging, usually two to four weeks, even after the rash appears to be gone.
To prevent the infection from spreading or recurring, maintaining good hygiene is necessary. This includes washing hands thoroughly after touching the rash or an infected animal, and washing clothes, towels, and bedding in hot water.
A person should consult a healthcare provider if the rash is widespread, fails to show improvement after two weeks of consistent OTC treatment, or if the area appears infected with increased redness or swelling. A doctor may prescribe a stronger topical medication or an oral antifungal drug for more severe or persistent infections.