Tinea nigra is an infection of the skin. It affects the outermost layer of skin. The infection will cause a black or brown patch on the skin. Except for the dark patch, tinea nigra is a harmless condition.
Tinea nigra usually affect the palms of the hands or soles of the feet. It may also appear on the neck or trunk.
Tinea nigra is caused by a fungus. The type of fungus that causes this infection is most often found in rotting wood, soil, compost, or sewage. The fungus may enter your body through a break in your skin.
You are more likely to develop tinea nigra if you have been living or traveling in tropical or subtropical areas, such as:
- South Africa
- Puerto Rico
- Coastal areas along the southeastern United States
Tinea nigra causes a brownish-black patch on the skin that:
- Has an irregular shape with a darker border
- May be itchy or scaly
- Tends to expand over time
A tinea nigra patch may be mistaken for a type of skin cancer. Talk to your doctor about any skin growth or changes.
Your doctor will ask about your symptoms and medical history. A physical exam will be done. You may need to see a skin specialist for tests, diagnosis, and treatment.
Tinea nigra is diagnosed by scraping a small sample of the affected skin. The sample is examined under a microscope.
Tinea nigra is usually treated with an antifungal medication. The medication is placed on the skin as creams or ointments.
To help reduce your chance of tinea nigra:
- Use care when traveling in high-risk areas.
- Avoid contact with potentially infected material, such as rotting wood, dirt, sewage, or compost.
- If you must work with any of the materials listed above, take the proper safety steps. Wear gloves and other protective gear.
- Reviewer: David L. Horn, MD, FACP
- Review Date: 12/2014 -
- Update Date: 12/20/2014 -