Fungi are microscopic organisms that, unlike green plants that produce chlorophyll, do not need light to live. Rather, they live off other living or dead organisms. Many fungi are so tiny that, like pollen, their spores can spread on the wind. The fungi kingdom includes toadstools, molds and yeasts. Some of these can cause skin disorders in humans.
Dermatophytosis
Dermatophytes are an aesexual species of fungi that live on dead tissue. In humans, the hair shafts, nails and top layer of skin are keratinized. These dead, hardened cells make a perfect environment for dermatophytes, especially in warm, moist areas on the body. The fungus thrives in parts of the body that are constricted by clothing, such as tighter underwear or socks.
When infected, the fungi cause scaled patches to develop on the skin. Ringworm, jock itch and athlete's foot are all skin disorders caused by dermatophytes. Symptoms of these disorders include rash, irritation, itching and pain. Dermatophytes can be passed from person-to-person, or via contact with infected soil or pets.
Candidiasis
Candida is a yeast-like fungus that lives on skin. It can affect any area of the skin's surface, though the groin area and armpit creases are the most likely places for infection to occur. Common in the obese and in diabetics, candida can cause diaper rash, oral thrush and vaginal yeast infections.
When candida infects creased areas of the body, red patches develop that ooze clear fluid and that itch and burn. A vaginal yeast infection causes a white or yellow discharge, as well as burning. Thrush appears as white patches on the tongue and inside the cheeks and can be quite painful.
Tinea (Pityriasis) Versicolor
Caused by the yeast, pityrosporum ovale, this disorder is more common in warm climates and appears more often on people who sweat heavily. It causes a well-demarcated plaque-like rash on the skin that appears as multi-colored patches. In some individuals, the rash will cause areas of hyperpigmentation (increased color), while in others, especially those with darker skin, areas of hypopigmentation (decreased color) are more common. The infection mainly affects the trunk, neck and arms, and is not common on other areas of the body. Mild itching may accompany the rash.
