Ringworm spreads through direct contact with an infected person, animal, object, or (rarely) contaminated soil. Despite the name, it has nothing to do with worms. It’s caused by a group of fungi that feed on keratin, the protein in your skin, hair, and nails. These fungi are surprisingly easy to pick up, and symptoms typically appear 4 to 14 days after your skin comes in contact with them.
Skin-to-Skin Contact With an Infected Person
The most straightforward way to get ringworm is by touching someone who has it. Any direct skin contact can transfer the fungus, including casual contact like a handshake or more prolonged contact during sports or sexual activity. Contact sports like wrestling carry particular risk because of sustained skin-on-skin pressure combined with sweat, which creates the warm, moist conditions fungi thrive in. Athletes who share helmets, knee pads, or uniforms raise their risk further.
A person with ringworm remains contagious as long as the infection is untreated. Once they start antifungal treatment, they’re generally no longer contagious after about 48 hours.
Picking It Up From Animals
Cats, dogs, rodents, horses, and cattle all carry ringworm, and you can contract it simply by petting or grooming an infected animal. Kittens and puppies are especially common carriers, and children are the most likely to catch it from household pets. Adults, on the other hand, are more likely to pick it up from horses through occupational exposure like grooming or saddling.
Livestock such as cattle and horses are more prone to ringworm during winter months, when they’re kept indoors and rub against stall materials that harbor the fungus. An animal doesn’t always look obviously sick. Some carry the fungus with only subtle hair loss or scaly patches that are easy to miss, so you can be exposed without realizing it.
Contaminated Objects and Surfaces
Ringworm fungi can linger on objects and surfaces that an infected person or animal has touched. Common culprits include towels, bedsheets, clothing, hairbrushes, hats, and combs. In gyms and locker rooms, shared mats and bare floors are frequent sources of infection, particularly for athlete’s foot (which is ringworm of the feet).
This is why sharing personal items is one of the biggest risk factors. If someone in your household has ringworm, using their towel or sleeping on their pillowcase can transfer the fungus to your skin. The same goes for borrowing clothes, hats, or sports gear from someone who’s infected.
Soil Exposure
Certain species of the fungi that cause ringworm live naturally in soil, where they feed on keratin from dead skin cells, feathers, and other animal debris. In rare cases, you can contract ringworm from prolonged contact with heavily contaminated soil. A brief brush with garden dirt is unlikely to cause infection. This route is uncommon compared to person-to-person or animal-to-person spread.
What Makes You More Vulnerable
Ringworm fungi need warmth and moisture to grow, so anything that keeps your skin damp raises your risk. Sweating heavily during exercise, wearing tight or non-breathable clothing, and staying in wet swimsuits or socks all create favorable conditions. Skin folds where moisture gets trapped, like the groin or between toes, are especially susceptible.
Minor cuts, scrapes, or areas of skin irritation also give the fungus an easier entry point. People with weakened immune systems are more likely to develop an infection after exposure, and children tend to be more susceptible than adults, partly because of closer contact with pets and shared items at school or daycare.
How to Reduce Your Risk
The core principle is simple: minimize contact with the fungus and keep your skin dry. In practical terms, that means not sharing towels, clothing, hairbrushes, hats, bedsheets, or sports gear. Wear sandals or flip-flops in locker rooms, public showers, and pool areas rather than walking barefoot.
- After exercise or sweating, shower promptly and change into dry clothes. Pay attention to areas between toes and in skin folds.
- With pets, take animals with bald patches or scaly skin to the vet. Wash your hands after handling any animal you don’t know well.
- In your household, if someone has ringworm, wash their bedding, towels, and clothing frequently and don’t share these items until 48 hours into their treatment.
- In sports, clean shared equipment regularly. Check your skin for unusual rashes before and after practice, especially in contact sports.
Since symptoms take 4 to 14 days to show up after exposure, you won’t always know immediately that you’ve been infected. A ringworm rash typically starts as a flat, scaly patch that expands outward with a raised, ring-shaped border while the center clears. If you notice this pattern, starting treatment early limits how long you’re contagious and prevents the infection from spreading to other parts of your body or to the people around you.