What is Lichen Nitidus?

Lichen nitidus is a rare and inflammatory skin condition with no known cause. It leads to the development of tiny, glistening bumps on various areas of the body. The bumps can be difficult to see because they are often the same color as the skin. However, they can present as lighter or darker than a person's skin tone or as various colors, including violet, yellow, or red-brown.

This article discusses the types, symptoms, and treatment options for those with lichen nitidus.

Types of Lichen Nitidus

There are several different variants of lichen nitidus, including:

• Generalized, which can appear anywhere on the body.
• Hemorrhagic/purpuric forms on the tops of the feet and around the ankles. Over time, the bumps spread up the legs.
• Vesicular, which develops on the palms and can blister.
• Actinic develops most often in people with darker skin tones after sun exposure.
• Linear occurs when the bumps form into a line instead of a cluster.
• Keratoderma develops on the soles of the feet and palms of the hands. This type mimics eczema because it can also cause fissures or cracks in the skin.
• Perforating, which is a form that affects the hands and forearms. The bumps may appear as though they have tiny belly buttons, a term known as umbilicated.

What Are the Symptoms of Lichen Nitidus?

The main feature of lichen nitidus is raised bumps. They typically appear on the torso, neck, forearms, abdomen, and genitals. However, they can affect any area of the body.

The following characteristics are typical of the bumps in lichen nitidus:

• 1 to 2 millimeters (mm) in diameter, roughly the size of a pinpoint
• Round or shaped like a polygon
• Mostly skin-colored, but can also be yellow, red-brown, or violet
• In people with darker skin tones, the bumps may present as hypo- or hyperpigmentation
• Shiny with a flat top
• Scaly appearance, in some cases
• In rare occurrences, blisters and ulcers may form
• The bumps form into clusters, which can then morph into plaques
• In some cases, they may form on top of stretch marks

The only symptom that appears alongside the bumps is itch. However, not all cases of lichen nitidus will present with irritation.

What Causes Lichen Nitidus?

The cause of lichen nitidus is unknown. However, older studies examining the condition found that specific cells in the immune system, T lymphocytes, may play a role. These cells are designed to help the body fight off infection and disease.

One older study published in 2005 found that these immune system cells are activated in people with lichen nitidus. It is thought that this is behind the inflammation and bumps present with the condition. The reason for the T-lymphocyte activation has yet to be discovered.

How Is Lichen Nitidus Diagnosed?

Healthcare providers will begin the diagnostic process by physically examining the bumps, documenting symptoms, and gathering a health history. To definitively diagnose lichen nitidus, they will may take a skin biopsy to look for microscopic characteristics of the condition, including:

• Lymphocyte (white blood cell) infiltration in the area
• Langhans giant cells, which are often present in the condition
• Ridges that go into the underlying connective tissue (Rete ridges) that are longer than usual

How Do You Treat Lichen Nitidus?

There is no cure for lichen nitidus, and treatment isn't always required. The bumps and other symptoms can go away in as little as one month or as long as one year.

However, treatments are available if the symptoms or cosmetic appearance are especially bothersome. Some possible therapies for lichen nitidus include:

• Topical or systemic corticosteroids to lower inflammation levels
• Immunosuppressant medications, including Tacrolimus
• Retinoids such as Acitretin, especially if the hands and feet are affected
• Phototherapy or exposure to sunlight
• Photochemotherapy, which is exposure to UVA radiation after being given a medication that makes the skin more sensitive to light

Summary

Lichen nitidus is an inflammatory skin condition that causes small bumps on the body. While the disorder is connected to inflammation, it is not yet considered an autoimmune disease. The cause is unknown, so risk factors are hard to iron out. Currently, medical researchers have made the connection between other inflammatory health disorders and lichen nitidus. However, it is unclear why people with specific health disorders are more often seen with lichen nitidus.

The only symptom seen with lichen nitidus is an itch. However, many people with the condition experience no symptoms besides the bumps. Because of that, a skin biopsy may be taken to diagnose the condition so that treatment can begin with light therapy, corticosteroids, retinoids, or immunosuppressants.