Ringworm is contagious for as long as the fungal spores that cause it remain alive. This may include while a person is undergoing treatment for the infection.

Ringworm is a fungal infection that causes ring-shaped lesions on the outer layers of the skin. These lesions are typically red and itchy, and they can appear on the scalp, extremities, or torso.

Ringworm is highly contagious. A person may contract ringworm from an infected pet or another person.

Several different types of fungi can cause ringworm. These fungi are contagious for as long as any of their spores remain alive, so it is important that a person disinfects anything that has come into contact with a person or animal who has the fungal infection.

This can include bedding, couch cushions, clothing, and other fabrics.

According to Seattle Children’s Hospital, ringworm is no longer contagious after 48 hours of treatment.

While undergoing treatment, a person can cover the lesion to help prevent it from coming into contact with other people or objects.

A dog or cat that receives proper treatment for ringworm will remain contagious for about 3 weeks. If the treatment is milder or inconsistent, the ringworm is likely to remain contagious for longer. Discuss treatment options with your pet’s veterinarian.

Ringworm spreads through direct contact with infected skin or fungal spores. The spores can live on fabrics, including clothing, couch cushions, bedding, and other porous surfaces. They also thrive in damp environments, such as public showers and locker rooms.

Ringworm is the same fungus that causes athlete’s foot and jock itch. If a person has ringworm, they should avoid touching their groin area or feet. Doing so could cause the ringworm to spread to these parts of the body.

While anyone can get ringworm, certain factors can increase a person’s risk, including:

  • living in a hot, humid environment
  • sweating heavily
  • participating in contact sports, such as wrestling or football
  • using locker rooms or public showers
  • wearing tight shoes and socks that cause moisture buildup
  • living or working in close contact with animals
  • having a weakened immune system

In many cases, it is possible to prevent ringworm. The following steps can help:

  • wearing loose, breathable clothing
  • wearing breathable footwear that is not too tight
  • changing underwear and socks at least once each day
  • keeping the skin clean and dry
  • avoiding walking barefoot in showers and other outdoor areas
  • showering immediately after playing a contact sport and keeping all sports kit clean
  • washing the hands with soap and water after playing with a pet
  • seeking veterinary treatment for an infected pet

Once a person or pet has ringworm, it is important to prevent the infection from spreading.

Preventing contagion between humans

A person who has ringworm can spread the infection both to other parts of their body and to other people. To prevent this, take the following precautions:

  • avoid scratching or touching the ringworm lesion
  • wash the hands thoroughly after touching or treating the ringworm lesion
  • wash clothes, bedding, and towels in hot, soapy water

People who have athlete’s foot should also take the following precautions:

  • avoid leaving worn socks lying around
  • use an ultraviolet shoe sanitizer or ozone cabinet to disinfect shoes
  • avoid walking barefoot in the home

People who have ringworm should avoid sharing their personal items, such as:

  • bedding
  • towels
  • clothing and accessories
  • hairbrushes
  • makeup

Preventing contagion from pets to humans

If a pet has ringworm, you can help prevent the infection from spreading by:

  • seeking veterinary treatment for the pet
  • having the veterinarian check other household pets for ringworm
  • cleaning, vacuuming, and disinfecting areas of the home that the pet spends time in
  • wearing gloves and long sleeves when handling the pet
  • washing the hands with soap and water after touching the pet

Treatment typically involves directly applying an antifungal cream to the ringworm lesion. These creams are available over the counter.

When applying the cream, cover the visible lesion and spread it to 2.5 cm beyond the lesion’s borders. Continue using the cream for at least 7 days after the lesion has completely cleared.

Ointments or creams should be applied for 2 to 4 weeks to clear a ringworm infection. However, the exact duration of the infection depends on the lesion’s location and severity.

A lesion on an area of the body with little to no hair may resolve sooner with treatment. If the infection is severe or in an area with a lot of hair, it can take longer to heal.

Ringworm on the scalp requires prescription medication, such as oral antifungals. A doctor may also prescribe a medicated shampoo.

Without treatment, ringworm can disappear within a few months. However, the person is contagious to themselves and others during this time.

Ringworm is a highly contagious fungal skin infection. It can occur anywhere on the body but is particularly common in the groin area and on the feet.

A person can use medicated ointments and creams to treat ringworm topically. For more severe infections, a person may need to take oral antifungal medications.

Ringworm remains contagious in people for the first 48 hours of treatment and in pets for about 3 weeks from the start of aggressive treatment. In both cases, untreated ringworm remains contagious for much longer.

The fungal spores themselves can live for up to 20 months. During this time, people should take the necessary precautions to prevent reinfection.