Fungal Skin Infections

Fungi are classified as microscopic plant organisms which unlike bacteria are made up of numerous cells. Fungi can be further subdivided into moulds (these have a single hyphae (a string like part of the vegetative portion of a fungus) and produce smooth velvety growth), mildews and yeast (yeasts consist of a single cell and they reproduce by budding, and produce yellow or white colonies.)

Fungi cannot make their own food and behave as parasites (live off living matter) or saprophytes (live off dead organic matter).

Fungi have a great tendency to cause infections in humans. The majority of fungi can be found in the environment as moulds and yeasts. They are very hardy organisms and are found in all types of climates and conditions. Some are even normal residents of humans, animals and plants.

Fungi are an important cause of skin infections. Estimates indicate that anywhere from 10-20% of all visits to a dermatologist are related to a fungal skin infection. The majority of fungal skin infections are caused by dermatophytes (skin loving fungi) which have a predilection for hair, nails of skin.

Whenever a fungus affects the skin, it is termed tinea meaning "ringworm". Tinea can affect various parts of the body and are very selective. The types of ringworm infections that can occur include:

- body (tinea corporis)- causes severe itching on the entire body

- jock itch (tinea cruris)- itching and redness in the groin

- athlete's foot (tines pedis)- itching and redness in the feet

- scalp (tinea capitis)- causes hair loss, itching and redness of the scalp

- nail (tinea unguium)- causes ugly deformity of the nails

- beard (tinea barbae)- causes patchy hair loss and itching

The majority of skin fungal infections are not life threatening and usually resolve with treatment. Fungal infections are serious in individuals who are immunocompromised, old or those who are in hospitals with multiple medical problems (e.g. AIDs).

The majority of skin fungal infections occur in individuals over the age of 14. However, Tinea Capitis, a fungal infection of the scalp does occur in children.

Fungi in general cause more skin irritation and itch than bacterial infections.

Other fungi that can cause skin infections include:

- Candida: Candida is usually found in the body creases and most common in diabetics. Candida is commonly found in the mouth and vagina and usually cause disease in immunocompromised individuals.

- Malassezia furfur is a type of fungus that causes brownish patches on the skin. It has a characteristic presentation which is associated with a rash on the chest and may also affect the scalp.