What Causes Ringworm On Human Skin?

A women hand with ringworm‬‏


This is all about the different causes of ringworm and how this skin infection gets passed on from one person to another.

Ringworm, also known as dermatophytosis or tinea, is a mold-like fungal infection that can cause a silvery or red rash or patches that are shaped like a ring on the skin. It is a common skin infection caused by fungi called ‘dermatophytes’. The fungi that cause this skin infection can live in the skin and the environment including surfaces, soil, things, clothes, towels, beddings, etc. Ringworm attacks dead tissues in the skin, nails, hair, and scalp but it is the body’s immune reactions that let ringworm live and make the skin red and itchy.

Ringworm can affect animals and humans of all ages but it commonly occurs in children and people who own pet dogs and cats. It is highly contagious and can be passed from person to person, animal to person, environment to person, and even non-living things to person and vice-versa.

Causes of ringworm


The world contains a lot of molds, yeasts, and fungi, and only a couple of them can cause skin disease. These agents that cause skin disease are called dermatophytes (skin fungi). Dermatophytes can only live on the dead layer of keratin protein which can be found on top of the skin. Keratin is a tough, waterproof tissue found in many body parts such as hair, nails, and skin. These are the body parts that have enough keratin to attract dermatophytes that’s why these are the common areas affected by ringworm. Dermatophytes usually live and spread on the outer layer of the skin. It is a rare occasion for them to deeply penetrate into the body. They can’t live on mucous membranes like the ones found in the ears, nose, or mouth.

There are three different types of skin fungi that can cause ringworm:
  • Trichophyton (Trichophyton rubrum, Trichophyton interdigitale, and Trichophyton tonsurans)
  • Microsporum canis
  • Epidermophyton floccosum

Skin fungi depend on their host, the infected human or animal, and they need to spread in order to survive. They are microscopic spores that are tough enough to survive for months on their host and are incredibly resilient to survive in objects as well such as towels and beddings. Some of them live exclusively on human skin, nails, or hair. Other skin fungi live on animals and can rarely be found on human skin. Some of them may live as spores in the soil for an extended period of time. Humans and animals can acquire ringworm when they come in contact with this soil.

It is almost impossible and very difficult to identify what causes a particular person’s skin fungus. The skin fungi may spread from:

  • person to person (anthropophilic)
  • animal to a person (zoophilic)
  • soil to the person (geophilic)

Skin-to-skin contact with an infected animal or person

The skin infection can spread through contact with humans or animals infected by ringworm. An infected person can cause an outbreak of the disease especially in schools where children are more susceptible to the disease. This infection can easily spread among children by sharing things that might not be clean, that’s why they should avoid sharing things like combs, brushes, and even toys. People who have ringworm should get immediate treatment to avoid spreading the infection.

Adults are less prone to contract this skin infection compared to children because of their immune system. People who have a weakened immune system due to medications or diseases such as cancer, diabetes, HIV, or organ transplants are also prone to having ringworm.

Those who have had a previous fungal infection are susceptible to having ringworm. If you have the skin infection on only a part of your body, do not allow other parts of your body to be in contact with that infected body part so that the infection will not spread to the other parts of your body.

Indirect contact with a surface touched by an infected animal or person

When an infected person or animal touches any object that has been touched by an infected person or animal, anyone who comes in contact with that exact same object is prone to having ringworm. This is the reason why you should avoid sharing personal things and clothes with people who are infected by ringworm.

If you come in contact with an object touched by a person or animal with the infection, immediately wash your hands with soap and water.

Heat and moisture

Heat and moisture help the dermatophytes develop and flourish that’s why they can be commonly found in skin folds just like the ones in between the toes or in the groin. Dermatophytes thrive in warm and humid places that’s why they are commonly found in tropical areas especially during the summer when it is hot and humid. They also grow in damp areas such as moist locker rooms, public showers, and public pools and for this reason, it’s a good idea not to walk barefoot in these kinds of places.

Lack of proper hygiene

Poor hygiene can cause ringworm in human skin. Since dermatophytes can live and thrive on almost anything, it is important to always practice proper hygiene. Always take a bath and change your clothes every day. Dirty clothes, socks, and underwear can also cause ringworm that’s why it is important to wear clean ones every day. As much as possible, choose to clothe made of absorbent cotton instead of the ones made of synthetic fabric.

To avoid ringworm, try to wear loose-fitting clothing and avoid wearing tight underwear, pantyhose, and pants as much as possible. Wash clothing and towels in hot water with fungicidal soap in case of exposure. Wash clothes regularly.

Wet skin and wet feet

Wet or sweaty skin and feet may cause ringworm. As dermatophytes thrive in moisture, they can also live and grow on your wet skin or feet. Putting socks without drying your feet can also cause ringworm on the feet which is more commonly known as ‘athlete’s foot’.

People who come into contact with skin fungi while they are wet or if they have minor skin abrasions or injuries are more likely to contract ringworm. The use of public showers and/or public pools may also expose one to the infectious ringworm.

Ringworm can also affect those who are fond of wearing tight-fitting clothes and those who allow their skin to stay damp for a long period of time. Staying in sweaty workout clothes or wet bathing suit for long periods can also increase the risk of having ringworm.

Take a shower immediately after working out to avoid sweating a lot which can put you at risk of having ringworm. Always keep the skin dry and clean. Always make sure that the skin is completely dry after taking baths or showers.

As much as possible, try wearing shoes that are open to avoid being afflicted with ringworm. Always dry your feet before putting socks and shoes on. If you are wearing closed shoes, always make sure that you are wearing socks for protection from dermatophytes that may live in the insides of your shoes.

Poor sanitation

Poor sanitation is also a big factor for human beings to contract ringworm. Dirty and wet surroundings carry a lot of bacteria and fungi and can easily spread to people who come in contact with them.

It is important to always keep your surroundings clean. Clean household surfaces with antibacterial cleaners. Public areas like bathrooms, pools, gyms, and showers should always be cleaned and well-maintained. A simple contact with the surface where an infected person has walked through or touched can already cause dermatophytes to grow on your skin.

Contact sports

Close contact sports can also cause ringworm especially if you are not aware that the other person that you are in contact with is infected by it. Wrestlers, football players, martial arts athletes and other athletes who are in close contact sports are at a higher risk of catching ringworm.

In case of doing or trying out sports that require a skin-to-skin contact, shower, and shampoo thoroughly right after. It is advisable for athletes to always observe proper hygiene after their sports activities and sanitize their sports equipment. Always clean your sports gears and equipment, uniforms, and accessories after every use and occasionally do a deep cleaning. Avoid sharing sports equipment, towels, and uniforms with other people.

Walking barefoot

People who are often barefoot may also develop ringworm of the feet or also commonly known as athlete’s foot since skin fungi also live and thrive on surfaces and public places such as showers, pools, bathrooms, and even ordinary floors.

Wearing of slippers or sandals in gyms, showers, locker rooms, and other public bathing areas are highly recommended to avoid ringworm infection.


Obesity may also cause ringworm on the skin. Obese people who have deep and moist folds are prone to having ringworm on their skin as the skin fungi can live and grow on these skin folds. It is advisable for obese people to shower and clean these skin folds regularly to avoid contracting ringworm.


House pets such as cats and dogs can carry and spread fungi that cause ringworm on human skin. Your pet should be brought immediately to the veterinarian in case your pet shows symptoms of fungal infection such as patches of missing hair or rashes.

Always wash your hands thoroughly after touching or holding animals. Any type of interaction or contact with infected animals can cause ringworm on your skin. Avoid animals with ringworm if you have a weak immune system. If you own a pet dog or cat, disinfect and clean pet living areas regularly.

Farm animals

Farm animals can also carry and spread fungi especially those that have come in contact with soil where dermatophytes reside. Ringworm is common in cows. Farmers who work closely with farm animals have a higher risk of getting ringworm and they usually get infected on the beard. Farmers who grow facial hair and come in contact with infected farm animals may get infected with ringworm on their beard.

Farm animals should always be cleaned and properly groomed to help them avoid ringworm infection. Farmers or anyone who comes in contact with farm animals should observe proper hygiene and wash their hands after touching these animals to prevent getting infected by ringworm.


Ringworm is basically caused by skin fungi or dermatophytes that live and grow on keratin found on the outer layer of the skin. Dermatophytes are tough and resilient spores and can live on humans, animals, soil, and objects for a long time. They also love places where it is hot and moist. They need to spread in order to survive which causes ringworm to be contagious. Simply touching or being in contact with any of these places where the dermatophytes live can cause ringworm on human skin. It is really important to have proper hygiene and maintain a clean environment.