White piedra, also known as trichomycosis nodular, is an infection caused by the restriction of pathogens to the stratum corneum, the outer layer of skin. This fungus infiltrates not only the skin but also the gastrointestinal tract. It can be caused by a few types of fungi found in nature.
Piedra originates from the Spanish word meaning stone. There are two different forms of piedra: black and white. Black piedra is usually found in tropical climates, whereas white piedra is found in more semitropical and temperate climates. This infection can be caused by one of the many fungi in the genus Trichosporon, and can also be caused by Acremonium SP.
Due to the climate white piedra grows in the fungus can be found in lake water, soil and plants. For this reason, many humans contract this fungus from animal hair and plant oil. The fungus from plant oil usually occurs in Brazil because native Brazilians are known to use their own human hair to grow the plants.
The bumps or nodules caused by this type of piedra can vary in color. They can appear anywhere from white to tan. The fungus can attach to any shaft of hair from the head to the toes. When examined, the nodules may produce a gritty sensation and area may appear to be red from irritation. This type of piedra can cause the hair to become very brittle.
There is a possibility this infection will be mistaken for lice infestation, but it cannot be treated in the same way. It usually produces reddish slightly bubbled patches in the groin or armpit area. If it is one of the more severe cases you will need to see a doctor. The most common way this infection is spread is by sharing hair accessories. If the infection is in the genital area, this is a sign of another infection called corynebacteria, and is likely to be spread by sexual contact.
This kind of piedra is sometimes confused with tinea capitis and trichomycosis axillaries, both of which are fungal infections. If a doctor suspects a patient is suffering from piedra, he or she will take a sample of the hair shaft and run diagnostic tests on it. Most of the time, white piedra can be treated with shaving the area and applying anti-fungal medicine. Topical or oral medication may be used, depending on the location of the fungal infection.
There may only be two variations of piedra, black and white, but both can become serious problems. If the condition is suspected, it is wise to have symptoms evaluated by a physician. This infection can attach itself to any hair follicle on a human or animal. White piedra has no preference of age, race, or sex; it will attach to anything it can.