Fungal infections are a common skin problem affecting about 15% of the population at any given time. Most skin fungi affect the enclosed areas, mainly the feet and groin, but a skin fungus can arise on any part of the body. Fungal infections of the skin are often referred to as a ringworm due to its characteristic round to oval lesions but should not be confused with nematode infections.
Causes of a Fungal Infection
Two types of fungi are responsible for skin fungal infections :
- Molds, also called dermatophytes.
- Yeast, also referred to as candida although other species may be involved.
A fungal infection of the skin will only arise if the conditions for the fungus to thrive is present – warmth, moisture and lack of direct sunlight. Fungal spores are a prevalent in the air in warm, tropical environments, in damp places like showers and public facilities or toilets. Upon contact, a fungal spore will attach to the skin, germinate (hatch) and start growing if the skin is broken, cut or irritated. A skin fungus usually consumes the outer layers of the skin and spreads on the surface of the affected body part.
In a nail fungus infection, the fungal spores may enter between the nail and the nail bed and quickly grow in this area. The use of acrylic nail polish and artificial nails usually increases the chances of a nail fungus, especially if these products are used constantly.
Dandruff is actually a skin condition called seborrheic dermatitis which causes scaling (not necessarily drying) of the scalp. Often, a case of seborrheic dermatitis (referred to as cradle cap when it affects the head of newborns) can become infected with a fungus. The regular use of hair relaxers, dyes and hair care products may also cause an irritation (contact dermatitis) of the scalp which may be followed by a fungal infection. On the head an yeast known as Pityrosporum ovale is usually the cause of a ‘head fungus’ complicating a pre-existing case of dermatitis. Usually the hair itself is not affected although fungal spores may adhere to the hair shaft and consume cells around the hair root.
Types of Fungal Infections
A fungus is usually named according to the area it affects and type of fungus (mold or yeast species). A fungal infection of the foot or feet (tinea pedis) is the most common fungal infection of the skin. Other fungal infections like jock itch (tinea cruris), head fungus/dandruff (tinea capitis) and a fungus under the breast (tinea mammae/submammary candidiasis) are also common occurrences in prone individuals.
Less commonly, fungal infections of the armpits (tinea axillae), facial hair or beard (tinea barbae) or hands (tinea unguium) may occur. In infants using diapers, a fungal infection of baby’s bottom (nappy rash) is often caused by the yeast, Candida albicans.
Symptoms of a Skin Fungus
- Cracked, peeling skin.
- Round or oval lesions, pale to white at the borders with a red center.
- Lesions may ooze a clear, sticky fluid (plasma)
- Severe itching especially when perspiring or hot.
- Damp, musty odor in enclosed areas like the feet, groin, breast and armpits.
- Dark discoloration of the skin over time.
Topical anti-fungals (creams, lotions and gel applications) are effective in most fungal infections of the skin. The affected area should be treated daily for 4 to 6 weeks and should be kept dry and exposed to air as much as possible. In severe cases, orally administered antifungals (ketoconazole) may be required, especially in immunocompromised patients as in HIV/AIDS sufferers.