Ringworm, or tinea, refers to several types of contagious fungal infections of the top layer of the skin, scalp, and nails.
It is called ringworm because the itchy, red rash has a ring-like appearance. However, ringworm is nothing to do with worms.
It can affect different parts of the body.
In this article, we will cover ringworm’s causes, symptoms, diagnosis, and treatment.
Fast facts on ringworm
Here are some key points about ringworm. More detail and supporting information is in the main article.
- Ringworm is nothing to do with worms.
- Ringworm is caused by a fungus that eats keratin, a protein found in skin, hair, and nails.
- Children under 15 are particularly susceptible to ringworm.
Treatment depends on the type of ringworm:
The most common treatments for scalp ringworm are oral antifungals (tablets). However, the choice of medication will depend on the type of fungi involved.
Terbinafine (Lamisil): The side effects are normally mild and do not last long. They may include diarrhea and nausea. People with a history of liver disease should not take terbinafine.
Anti-fungal shampoos: These help prevent the spread of ringworm and may speed up recovery, but they do not cure it. Various anti-fungal shampoos are available for purchase online.
Shaving a child’s head: There is no evidence that this reduces ringworm infection or accelerates recovery time.
Skin ringworm and groin infection
Most cases are treated with anti-fungal creams. Individuals should read instructions carefully – anti-fungal creams do not all have the same instructions. These can be purchased over-the-counter or online.
If symptoms are severe, or if they cover a large area of the body and do not respond to OTC medications, the doctor may prescribe a prescription-strength topical medication.
The doctor may prescribe an oral medication (taken by mouth). Oral medications can have some side effects, including stomach upset, rash, or abnormal liver function.
Caring for the skin during infection
Care for the skin properly can help speed recovery.
- Wash the skin gently
- Dry the skin thoroughly but gently.
- Pat the skin with a towel in tender areas, but do not rub.
- Make sure any folds and areas between the toes are dried thoroughly.
- Change sock or underwear more often than usual if they cover an infected area.
- Always treat the feet and groin at the same time, as infection often spreads from one area to another.
- Where possible, wear loose-fitting clothing and undergarments, such as boxers.
Different types of ringworm affect different parts of the body.
- Scalp ringworm (tinea capitis): This is most common in younger children, and occasionally it affects adults. It is more common in urban environments where people live closer together, giving the fungus more opportunities to spread.
- Body (skin) ringworm (tinea corporis): This can affect infants, children, and adults.
- Groin infections (tinea cruris): Also known as jock itch, this is more common among young men.
- Tinea pedis: Athlete’s foot is a common foot infection.
- Tinea unguium: Also known as onychomycosis, it is an infection of the nail bed.
- Ringworm in the beard area: This affects males who can grow facial hair, and it often results from contact with an animal that has ringworm.
Different types have different symptoms.
- small patches of scaly skin appear on the scalp.
- patches may feel tender or painful and be inflamed.
- hair breaks away on or near the patches
- kerion, or large inflamed sores, form on the scalp, and they may ooze pus
The person may have a temperature and swollen glands or lymph nodes, but this is uncommon.
Body or skin ringworm
- a rash with a ring-like appearance
- the skin may be red and inflamed around the outside of the ring, but look fine in the middle
- merging rings
- rings feel slightly raised
- itchiness, especially under the rash.
There may be:
- itchiness, especially in and around the groin
- redness and a burning sensation in the affected area
- flaky and scaly skin on the inner thighs
- symptoms worsen when walking, running, or exercising
- tight clothing makes symptoms worse
This can involve:
- redness, swelling, and pus-filled bumps
- hair loss, which usually resolves after treatment
- swollen glands
- raw, open skin and raised, soft, spongy patches that weep
Fungal infections rarely spread below the surface of the skin. The risk of any serious illness is very small. However, without treatment, ringworm can spread from one part of the body to another.
If the skin is broken, bacteria may enter and cause an infection.
People with HIV and other conditions that weaken the immune system are more likely to experience a spreading of ringworm. It is more difficult to get rid of the infection if the immune system is weak.
Ringworm is caused by a type of fungus that eats keratin. These are called dermatophytes.
Dermatophytes attack the skin, scalp, hair, and nails because those are the only parts of the body with enough keratin to attract them.
Dermatophytes are microscopic spores that can survive on the surface of the skin for months. They can also survive in towels, combs, the soil, and other household objects. They are very resilient.
Dermatophyte spores spread in the following ways:
If a person or animal has the infection, they may deposit fungal spores on objects and surfaces when they touch them; anyone who touches those objects may become infected.
Children usually show symptoms when they become infected, but many adults do not. The older an individual is, the more likely their immune system will protect them. However, they may still be a carrier.
The following risk factors either increase the chances of developing ringworm or make the symptoms worse:
- being aged under 15 years
- having a weakened immune system
- using medications that lower the immune system
- living in a warm, humid climate
- being close to people or animals that are infected
- sharing clothing or towels with someone who has the infection
- having hyperhidrosis, a condition where the individual sweats more than usual
- playing contact sports, for instance, wrestling
- wearing tight clothing
The stages in which ringworm develops depend on the type of ringworm.
On the body, patches grow slowly in size, and more patches can appear on other parts of the body. The center of the patch may clear, leaving a ring. If there are several rings, they may merge.
Athletes foot tends to start between the toes before spreading to the bottom or sides of the feet, or both. The skin between the toes can then turn white and become soft.
On the nails, ringworm starts with a thickening of the skin under the nail, followed by a thickening and discoloration of the nails. Over time, the nails will lift, crumble, and disappear.
In the groin, the first sign is usually an itchy rash in the crease where the leg meets the body. This can spread to the groin, the inner thigh, the waist, and the buttocks.
A doctor can normally diagnose ringworm or a groin infection after examining the affected area and asking the patient about their medical history and symptoms.
They may take a small scraping of the skin, which will not hurt, and examine it under a microscope to look for characteristics of fungi.
The doctor will assess whether the skin problem is being caused by some other disorder, such as psoriasis. Further testing is not usually needed unless symptoms are particularly severe.
If symptoms have not improved after treatment, the doctor may remove a small piece of infected skin and send it to the lab to be analyzed.
The following tips may help prevent ringworm if it occurs in a household:
- If a pet is the source of the infection, it should be treated by a vet.
- Everyone should wash their hands regularly and thoroughly with soap.
- All household members should check themselves for signs of ringworm.
- People should not share combs, hairbrushes, clothing, bed linen, towels, or footwear.
- Anyone who has ringworm should not scratch affected areas as this increases the risk of spreading the infection.
- People should avoid walking around the house with bare feet.
- Clothes should be washed in hot water with fungicidal soap.
Keeping cool and wearing loose clothing may help reduce the risk.