Fungal skin infections

Various germs such as fungi and bacteria live harmlessly on the skin and inside the body. However certain types of fungus, or overgrowths of normally harmless types can cause the symptoms of a fungal infection of the skin.

Most fungal skin conditions are not serious and are usually not easily spread from person to person. Infections deeper in the body can be more serious.

Symptoms of fungal infections

The symptoms and appearances of a fungal skin infection depend on the type of fungus causing it and the part of the body affected. The rash may have a variety of appearances. Some are red, scaly and itchy, whereas others can produce a fine scale similar to dry skin. The site of infection may be just one area of the body, or there may be several infected areas. Fungal rashes can sometimes be confused with other skin conditions.

Types of fungal skin infections

Fungal infections usually affect the skin because they live off keratin, a protein that makes up skin, hair and nails.

Fungal skin infections are divided into groups depending on what type of organism is involved. The full name depends on the location of the infection on the body.

The most common fungal infections are listed below.

Jock itch (tinea cruris)

This is called "jock itch" because it occurs in sportspeople. It causes an itchy, red rash in the groin and surrounding area and is commonly seen in men who have been sweating a lot. Often the man also has athlete's foot, and scratching the feet followed by the groin may spread the infection.

Ringworm on the body (tinea corporis)

This affects the body, often in exposed areas and causes red patches, which are scaly at the edge with clear skin at the centre. The patches spread out from the centre. It can be caught from domestic animals. Ringworm of the scalp tends to affects young children and can cause hair loss with inflammation in the affected area.

Pityriasis versicolor

This condition causes increased dark patches on pale or untanned skin and light patches on tanned or darker skin. Another name for this condition is tinea versicolor. People with oily skin are most likely to be affected.

Causes of fungal infections

A number of situations make it more likely that a fungal infectin will develop. People are more at risk of fungal infections if they have:

·        ·        Antibiotics

·        ·        An immune system weakened by cancer or HIV infection

·        ·        Oral steroids

·        ·        Diabetes

Moist skin encourages fungal infections. This means fungal infections are more likely when skin is not dried properly after sweating heavily or bathing, or when it is covered with a material that does not allow sweat to evaporate. Damage to the skin surface, such as a cut or graze, can also encourage fungi to grow.

Fungal infections inside the body can cause more serious health problems than those on the skin. These infections only affect people whose immune systems are not working properly as a result of another illness or treatments for cancer.

Diagnosis

Sometimes fungal infections are easy for doctors to diagnose from the appearance and location of the rash, e.g. athlete's foot. If the doctor wants to make sure what is causing the symptoms, he or she may take a scraping of skin or a fragment of nail or hair and send it to the laboratory for analysis before choosing the treatment.

Treatment

Since most skin fungal infections are surface infections, they are usually anti-fungal treatments applied directly to the infected area (topical treatments).

There are a variety of treatments available in the form of creams, lotions and medicated powders. If the rash covers quite a large area of skin, or affects nails or hair, then tablets may be required.

Some treatments are available over the counter from a pharmacist, without a prescription. Examples include clotrimazole, miconazole and terbinafine. Pharmacy own-brands are also available for some of these products. Ask your pharmacist for advice.

Stronger forms of topical treatments and antifungals in tablet form are only available on prescription. For example, ketoconazole shampoo (e.g. Nizoral) may be prescribed for fungal scalp infections, and terbinafine tablets may be prescribed for fungal nail infections.

These treatments are usually effective and only occasionally cause side effects. These may include skin irritation and allergic reactions. It is not unusual for the rash to return, even when it seems to have been treated. The treatment may need to be used for at least four weeks to prevent the rash from coming back.

Anyone buying over-the-counter treatments needs to be sure that it is a fungal infection that they have. They may recognise a rash that has been previously diagnosed as fungal. If there is any doubt about the diagnosis, or if over-the-counter treatments do not work, then you should seek advice from your GP.

Helping prevent fungal infections

Taking these steps may help to reduce the risk of getting a fungal infection:

• Dry the skin carefully after bathing
• Wear loose fitting clothes and underwear
• Avoid sharing towels, hairbrushes, and combs, which could contain skin fragments that harbour fungal colonies
• Change socks or tights daily
• Choose fabrics that allow the skin to "breathe" - natural fibres such as cotton are better than nylon or polyester for underwear
• For sportspeople, synthetic fibres that "wick" the sweat away from the body, helping to keep the skin dry, may be preferable
• People with diabetes need to keep good control of their blood sugar