What is Lichen Nitidus?

Lichen nitidus appears as shiny, skin-colored bumps or papules about the size of a pinhead. Each one measures one to three millimeters, and they often appear in clusters. The rash most often develop on the arms, legs, and torso, and occasionally the genitalia. Children and young adults are the most commonly affected demographics, but lichen nitidus can affect people of any age.

The appearance of small bumps is the only symptom of lichen nitidus. They rarely appear on the palms of the hands or the soles of the feet but can develop just about anywhere else. Usually, they are the same color as the skin but may differ depending on skin color. The bumps may appear brighter on people with dark skin or pinker on those with light skin. They may clear up in one part of the body and reappear on another. Sometimes, the rash develops along scratches, creases, and skin folds.

Generally, lichen nitidus does not cause itching or any other symptoms. In some cases, however, the bumps can itch intensely, which makes it difficult to avoid scratching, especially for young children. If a person experiences this rare sensation, a physician may prescribe an anti-itch medicated cream to relieve this symptom.

Lichen nitidus appears to develop due to inflammation controlled by T lymphocyte, white blood cells that normally work to heal injuries or fight disease. Researchers are not sure what causes the reaction in T lymphocytes that leads to lichen nitidus. Although the condition is fairly rare, it does seem to have some links to other diseases that are not yet fully understood.

Several diseases may be associated with lichen nitidus. Lichen planus is another inflammatory condition that causes flat purple or red itchy bumps to appear on the skin; it may also develop as white patches in the mouth. Eczema, a dry, itchy rash behind the knees, inside the elbows, or on the face, hands, or feet, may also be connected to lichen nitidus. Crohn's disease and juvenile rheumatoid arthritis may also be connected.

Lichen nitidus follows the Koebner phenomenon, which is well-known in dermatology as lesions that form in previously uninvolved areas of the skin after trauma. In lichen nitidus, this causes the papules to appear in a linear shape. The Koebner phenomenon is not fully understood, but scientists believe it may have something to do with the injury and a release of stress proteins, autoantigens, and adhesion molecules.

A few conditions can cause skin reactions, so it is best to see a doctor if any bumps appear on the skin. The doctor or dermatologist may diagnose lichen nitidus based on other symptoms or a lack of them. They may use a magnifying glass to closely inspect the skin, or take a biopsy for further study.

If lichen nitidus itches or if the individual is bothered by the look of the bumps, doctors may prescribe some basic medications. Antihistamines can relieve any itching, while corticosteroids reduce inflammation. The latter cannot be taken long-term, however. Retinoid, a synthetic version of vitamin A, can also be effective but should be avoided by pregnant women as it can cause congenital disabilities.

Some doctors may use one of two phototherapy techniques to treat lichen nitidus. One uses UVA light, which penetrates deep into the skin and is usually combined with medication to make the skin more sensitive to the treatment. A second option uses UVB light. People receiving phototherapy should avoid the sun for a few days following treatment.

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In most cases, lichen nitidus goes away on its own without treatment, which is generally pursued only if the individual experiences severe itching or is self-conscious about the appearance of the small bumps. After the rash clears, the skin usually returns to normal, leaving behind no discoloration or scarring.