Overview
Fungal skin infections, called tinea, are caused by a group of fungi that live on the dead outer layer of skin, hair and nails. They are very common in hot, humid weather and where skin stays damp under clothing.
They are named after the part of the body affected: ringworm of the body, dhobi itch or jock itch in the groin, athlete's foot between the toes, scalp ringworm, and fungal nail infection. Despite the English name, no worm is involved. The fungus can also infect nails, making them thick, discoloured and brittle.
Symptoms
The typical rash is itchy and scaly, often ring shaped with a raised, active edge and clearer skin in the middle. It looks red on lighter skin and grey or brown on brown and black skin.
- Body: one or more itchy scaly rings that slowly widen
- Groin: an itchy rash spreading from the fold towards the thigh
- Feet: itchy, white, soggy or flaky skin between the toes, sometimes cracked or sore
- Scalp: scaly itchy patches, broken hairs and patchy hair loss
- Nails: thickening, colour change and crumbling, usually in toenails
When to see a doctor
See a doctor within a few days if the rash has not cleared with a pharmacy antifungal, if it keeps coming back, if it is on the scalp or in the nails, if it got worse after a cream containing a steroid, or if you have diabetes or reduced immunity.
Causes
The infection is caused by dermatophyte fungi, mainly from the Trichophyton, Microsporum and Epidermophyton groups. They feed on keratin, the protein in the outer skin, hair and nails, and grow well where skin is warm and moist.
They spread by skin-to-skin contact with an infected person or animal, by sharing towels, clothes, combs, footwear or bedding, and by walking barefoot on wet floors in bathrooms and changing rooms. Pets, especially cats and dogs with bald scaly patches, are a common source in children.
Risk factors
- Hot, humid weather and heavy sweating
- Tight clothing, tight shoes and synthetic socks
- Walking barefoot in shared bathrooms, changing rooms and pools
- Sharing towels, clothes, combs or footwear
- Close contact sports such as wrestling and kabaddi
- Living or sleeping close together where one person is affected
- Close contact with animals, including street and pet cats and dogs
- Diabetes, or a weakened immune system
Complications
Scratching breaks the skin and can let bacteria in, causing a painful spreading infection that needs . Scalp infection can leave patches of hair loss, and rarely a boggy, tender swelling that scars if treatment is delayed.
Infections treated with steroid creams tend to become widespread, stubborn and slow to respond, and they often come back. Cracked skin between the toes is an entry point for infection, which matters most in people with diabetes.
Prevention
- Keep skin clean and dry, drying carefully between the toes and in skin folds
- Wear loose cotton clothes, and change socks and underwear daily
- Wear slippers in shared bathrooms and changing rooms
- Do not share towels, clothes, combs, footwear or bedding
- Wash and dry clothing, towels and bedding of an affected person separately
- Keep nails short and clean
- Wash hands after handling pets, and have an animal with bald scaly patches seen by a vet
- Treat everyone at home who has the rash at the same time
Diagnosis
A doctor or pharmacist can often recognise the rash by its appearance and where it sits. Tell them if any cream has already been used, because a steroid changes the way the rash looks.
When the diagnosis is not clear, a small scraping of skin or a nail clipping is taken and examined or grown in a laboratory. That confirms the fungus, rules out conditions that look similar such as eczema or psoriasis, and guides the choice of medicine.
Treatment
Infections of the body, groin and feet are usually treated with an antifungal cream, spray or powder, several of which are available from a pharmacy. It is applied to the rash and a little beyond its edge, and continued for as long as directed, commonly two to four weeks, even after the skin looks normal.
Antifungal tablets are needed for infection of the scalp, for nail infection, and for widespread or stubborn rashes. Scalp treatment usually runs for one to three months and nail treatment for several months. These tablets are prescribed, and some need blood tests or a check of other medicines being taken.
Creams containing a steroid should not be used to treat a fungal infection. If the rash was treated with one and has spread or looks unusual, tell the doctor, as it may need a longer or different course. Washing clothes, towels and bedding in hot water and drying them well helps stop it returning.
Myths and facts
Things people often say about this. Open each one to see what is true.
Myth“Ringworm is caused by a worm under the skin.”What is true?
Fact
It is caused by fungi, not by a worm. The name comes only from the ring shape of the rash. Deworming tablets do nothing for it, and the treatment is an antifungal medicine applied to the skin or, for some sites, taken by mouth.
Myth“The combination cream from the medical shop is the fastest cure for daad.”What is true?
Fact
Many creams sold over the counter combine an antifungal with a strong steroid. The steroid settles the itch for a few days but weakens the skin's defence against the fungus, so the infection spreads over a wider area and the burning and redness can become more severe. It also changes how the rash looks, which makes it harder for a doctor to diagnose. Fungal infections should be treated with an antifungal, chosen by a pharmacist or doctor.
Myth“Once the itching stops, the cream can be stopped.”What is true?
Fact
The rash settles before the fungus is gone. Antifungal creams are used for as long as directed, commonly two to four weeks, and often for a while after the skin looks normal. Stopping early is one of the main reasons the infection returns.
Myth“Ringworm of the scalp can be cleared with a cream or a medicated shampoo alone.”What is true?
Fact
Creams and shampoos do not reach the fungus inside the hair, so scalp infection is treated with antifungal tablets, usually for one to three months, sometimes alongside a shampoo. Left untreated it can cause patchy hair loss, so it needs a doctor.
Questions to ask your doctor
Tick the ones you want answered and take them with you.
Common questions
Why does my daad keep coming back?
The commonest reasons are stopping the cream as soon as the itching settles, treating only part of the rash, using a cream that contains a steroid, and re-catching it from someone else at home or from unwashed clothing and bedding. Finishing the full course, treating everyone affected at home and washing linen well all reduce the chance of return.
Can I catch ringworm from my pet?
Yes. Cats and dogs, including street animals, can carry the fungus and pass it on, and a pet with bald, scaly or crusty patches should be seen by a vet. Wash your hands after handling animals, and avoid close contact until the animal has been treated.
Is it safe to use the leftover cream a relative was given?
It is better not to. The rash may not be the same condition, the cream may contain a steroid that would make a fungal infection worse, and the amount left is usually too little for a full course. Ask a pharmacist or doctor which antifungal suits the site and how long to use it.
Should the whole family be treated?
Everyone at home who has the rash should be treated at the same time, otherwise the infection passes back and forth. People with no rash do not need medicine, but should avoid sharing towels, clothes and bedding, and should tell a doctor if a patch appears.