Lichen nitidus (LIE-kun ni-TIE-dus) is a rare skin condition that usually appears as tiny, skin-colored, glistening bumps on the surface of your skin. Lichen nitidus results from abnormal inflammatory activity in skin cells, but the cause of inflammation is unknown.
Although lichen nitidus may affect anyone, it typically develops in children and young adults. Lichen nitidus rarely causes discomfort and usually clears up on its own without treatment.
Lichen nitidus doesn't increase your risk of skin cancer, and it isn't an infectious disease that can spread to other people.
Lichen nitidus appears as clusters of tiny, glistening bumps (papules). Characteristics of the bumps include the following:
- Size. The bumps range in size from pinpoint to pinhead size.
- Shape. They are flat topped and round.
- Color. Bumps are usually the same color as your skin. They may be slightly pink on people with lighter skin, or lighter than normal skin color on people with darker skin.
- Location. Lichen nitidus bumps commonly occur on the chest, abdomen, arms and genital areas, including the penis. They rarely occur on the palms, soles of the feet or fingernails. Lichen nitidus may clear up at one site on your body but then appear at another.
- Itch. In rare cases, the bumps of lichen nitidus may itch, sometimes intensely. They may appear in a line where there's a scratch, crease or constant pressure on the skin, such as a fold of skin on the abdomen or the crease of skin on the inside of the elbow or wrist.
When to see a doctor
See your doctor if tiny bumps or a rash-like condition appears on your skin for no apparent reason, such as a known allergic reaction or contact with poison ivy. Because a number of conditions can cause skin reactions, it's best to get a prompt and accurate diagnosis.
Get immediate care if your skin condition is accompanied by other signs and symptoms, such as:
- Pus or oozing from a rash
The cause of lichen nitidus is unknown. The papules that appear are the result of inflammation controlled by white blood cells called T lymphocytes. Normally, these cells work to heal disease or injury, such as a cut on your finger. Doctors and researchers don't know what prompts T lymphocytes to be activated in lichen nitidus.
Lichen nitidus seems to be more likely to develop in children and young adults.
Association with other diseases
Because lichen nitidus is rare, most information about the disorder is known from individual cases or small studies. Links between lichen nitidus and other diseases aren't well-understood, but they may include:
- Lichen planus, an inflammatory condition usually characterized by patches of red or purple, flat-topped, itchy bumps on the skin or lacy white patches on the mucous membranes of the mouth
- Atopic dermatitis (eczema), an inflammatory skin condition usually characterized by dry, itchy rashes on the face, inside the elbow, behind the knees, and on the hands and feet
- Crohn's disease, inflammation of the lining of your digestive tract, which can lead to abdominal pain, severe diarrhea and malnutrition
- Juvenile rheumatoid arthritis, an inflammatory disease that causes persistent joint pain, swelling and stiffness
- Tuberculosis, an infectious disease that most often affects the lungs
Lichen nitidus is a harmless condition that doesn't result in long-term skin problems or medical complications. However, the appearance of lichen nitidus may cause a person to be self-conscious or embarrassed.