What is Lichen Nitidus?
Lichen nitidus is a rare and long-term skin condition that was first identified in 1907 by a scientist named Pinkus. It’s recognized by its specific appearance on the skin and by how it reacts under the microscope, though we don’t yet fully understand what causes it or how it develops.
This unusual skin rash is more commonly found in children and young adults, and it can occur in both men and women of any race. Lichen nitidus shows up as many tiny, shiny, flat bumps on the skin that are pale or match the skin’s color. Each bump is usually only 1 to 2 millimeters wide. These bumps often appear on the arms, legs, stomach, chest, and penile shaft.
In most cases, lichen nitidus doesn’t cause any symptoms or pain, so treatment is usually only needed if the person finds the bumps bothersome or is not happy with how they look.
What Causes Lichen Nitidus?
Lichen nitidus is an unusual skin condition whose exact cause is unknown. There’s a theory that it may be hereditary since there have been reports of the condition appearing in families. It’s been observed alongside another skin condition called lichen planus, which has caused some to suggest they might be caused by similar factors. However, research has indicated that lichen nitidus is not a type of lichen planus.
There have also been reports of lichen nitidus occurring in connection with several other conditions and circumstances. These include Crohn’s disease, an intestinal condition; Niemann-Pick disease, a group of inherited metabolic disorders; and amenorrhea, a condition where menstruation stops. Some people have developed lichen nitidus after getting a tattoo. A widespread form of lichen nitidus has also been linked to Down’s syndrome, and people who are living with advanced HIV. Furthermore, there has been a case where widespread lichen nitidus developed after a person had been treated for hepatitis C with two drugs, interferon-alpha and ribavirin.
Another form of lichen nitidus, known as generalized purpuric lichen nitidus, is even rarer. There has been a case reported where this condition appeared after someone was treated with a drug called nivolumab. This drug works by boosting the immune system’s response to cancers like melanoma and a type of lung cancer known as non-small cell lung carcinoma.
Risk Factors and Frequency for Lichen Nitidus
Lichen nitidus can affect anyone, regardless of gender or race. It is more commonly seen in children and young adults. However, there have been cases reported in older adults as well.
Signs and Symptoms of Lichen Nitidus
Lichen nitidus generally appears as small, glossy, flat-topped bumps that are pink or brown. The size of these bumps is usually 1 to 2 mm. In people with darker skin, the spots may appear lighter. Common areas for these to appear are the neck, trunk, limbs, belly, and penile shaft. It’s uncommon for the palms, soles, mucous membranes, and nails to be affected but cases have been reported. If symptoms are present, there could be occasional mild itching. A characteristic of lichen nitidus, similar to lichen planus, is the Koebner phenomenon, but it doesn’t happen in all cases.
Rarely, lichen nitidus may only occur on the soles and palms, usually with the presence of lichen nitidus in other body parts.
If lichen nitidus appears in the mouth, the lesions may appear as flat, grayish bumps.
It’s not common for nails to be affected, but if they are, there may be grooves and ridges on the nails due to inflammation of the nail bed. Additionally, if the skin fold around the nail is affected, you may see unspecified inflammation around the nail or shiny violet bumps. The affected nails may thicken, develop ridges, pits, or they may detach.
There are several types of lichen nitidus, including:
- Confluent
- Hemorrhagic
- Linear
- Perforating
- Spinous follicular
- Vesicular
- Generalized
- Actinic
When lichen nitidus is hemorrhagic (also called purpuric), it’s quite rare and appears as reddish-brown bumps caused by bleeding beneath the skin. A type of this known as purpuric generalized lichen nitidus is extremely uncommon. Microscopic examination of these lesions reveals bleeding beneath the skin surface and damage to the small blood vessels.
There’s a type of lichen nitidus known as actinic lichen nitidus which usually appears as tiny bumps in areas exposed to the sun. It’s often seen in children and adults with certain skin types. These bumps can sometimes form ring-like patches, and on a microscopic level, they may look like lichen planus. This type is believed to be a variant of a skin condition triggered by sunlight.
Lichen nitidus in a line can resemble another skin condition called lichen spinulosus.
Testing for Lichen Nitidus
Doctors can often identify Lichen Nitidus, a skin condition, just by examining your skin. However, sometimes a skin biopsy might be performed, providing a more definitive diagnosis confirmed by looking at the distinctive features of the skin under a microscope.
A tool called a dermoscope can also be very useful for diagnosing Lichen Nitidus. This device can reveal smooth, white circles about the size of a pinhead (1-2mm) with what looks like a brown shadow behind them. These white circles are areas of skin thickening, and the brown shadow represents the cells causing the condition in the deeper layer of the skin. Dermoscopy can be crucial to differentiate Lichen nitidus from other skin conditions.
Interestingly, in patients with this condition on the palms of their hands or the soles of their feet, a dermoscopic examination shows thick, hardened skin with small pits and depressions covered with thin scales.
Treatment Options for Lichen Nitidus
Patients with this condition often don’t show any symptoms, and the skin lesions typically clear up on their own within months to a year. Treatment is generally only necessary for lesions that are causing noticeable discomfort or are affecting the patient’s appearance.
There are a variety of potential treatment options. Topical corticosteroids and systemic corticosteroids can be used to reduce inflammation and calm itching. Topical calcineurin inhibitors like tacrolimus can help suppress the immune system to reduce inflammation and itching. For patients with more stubborn or widespread cases, other treatments like narrow UVB rays, phototherapy (PUVA treatment), H1 receptor blockers, antifungal medicine like itraconazole, and other medications might be considered.
For chronic or long-lasting cases of this condition, topical or systemic corticosteroids are potential options. If the condition becomes widespread, treatments such as phototherapy, topical or systemic corticosteroids, and different forms of immune therapy can be effective. For patients whose condition affects the palms of their hands and the soles of their feet, acitretin (a medication that affects skin growth) can bring good results. If the condition impacts the nails, corticosteroid injections directly into the affected area might be necessary.
It’s worth noting that narrowband UVB rays are considered less likely to increase cancer risk compared to broadband UVB rays or PUVA treatment. The exact way these treatments work is unclear, but it’s thought that they work by reducing the number of cells that trigger immune responses in the skin (epidermal Langerhans cells). Another medication, cyclosporine, has been found beneficial for more severe widespread cases of the condition.
There’s also been a documented case where a patient with diffuse itchiness and concerns about appearance saw improvement after taking isotretinoin, a type of medication known as a retinoid, for four months. This drug is thought to help control inflammation and prevent excessive skin cell growth.
The skin bumps (papules) seen in this condition can sometimes leave behind areas of darker skin (post-inflammatory hyperpigmentation), but these usually go away in a matter of months.
What else can Lichen Nitidus be?
When a doctor is trying to diagnose a skin condition, they have to rule out other diseases that might cause similar symptoms. These could include:
- Lichen planus
- Keratosis pilaris
- Follicular eczema
- Lichen sclerosus et atrophicus
- Lichen spinulosus
- Pigmented purpuric dermatosis
It’s important to keep these possibilities in mind to make sure they make an accurate diagnosis.
What to expect with Lichen Nitidus
Lichen nitidus is a kind of skin condition that typically gets better on its own and generally doesn’t cause any symptoms that would require treatment. Most of the time, it clears up within a few months up to a year.
If lichen nitidus starts to cause discomfort or become noticeable in a way that affects your appearance, then there are treatment options available.
Possible Complications When Diagnosed with Lichen Nitidus
Lichen nitidus, a skin condition doesn’t usually cause any symptoms. However, sometimes, the skin lesions may become slightly itchy, or they might affect the nails, palms, soles of your feet, or the mucous membranes in your body. Generally, treatment isn’t needed, as the condition usually clears up on its own within several months to a year.
Common Features:
- No symptoms generally
- Skin lesions may become slightly itchy
- Occasionally affects nails, palms, soles, and mucous membranes
- Usually doesn’t require treatment
- Resolves on its own within several months to a year
Preventing Lichen Nitidus
Patients need to understand that lichen nitidus is a harmless condition and that the skin changes it causes will likely disappear on their own over time. If the skin changes cause discomfort or if patients are worried about how they look, they should also know that there are treatment options available to them.