Lichen nitidus is a relatively rare, chronic skin eruption. Lichen nitidus is characterized clinically by asymptomatic, flat-topped, skin-colored micropapules. Lichen nitidus may affect anyone, but typically develops in children and young adults. Lichen nitidus is a benign disease with no associated mortality or complications. The cause of lichen nitidus is unknown. It consists of tiny, skin-colored bumps (papules) that often appear in clusters on the surface of the skin, especially on the arms and legs.
Even without treatment, lichen nitidus usually disappears over time. The papule of lichen nitidus consists of a lymphohistiocytic inflammatory cell infiltrate that lies in close proximity to the epidermis and is associated with basal cell hydropic degeneration.
Certain parts of the body are more affected like trunk, arms, and genitals. Sometimes it can be seen in palms, soles or inside the mouth. Lesions are often found on the forearms, and trunk. It usually does not respond to topical steroids and resolves without treatment over a period of months, but the duration of lesions is variable.
Lichen nitidus is a rare skin condition that the frequency of its incidence internationally remains vague. No mortality or morbidity is being associated as lichen nitidus is generally a benign condition and causes no complications. The skin condition is known to affect both boys and girls although it has found to have a slight prevalence among girls. It can affect people worldwide without racial predilection. The disease is prevalent among pre-school and school aged children including young adults but can also occur in older adults.
Lichen nitidus is not a life-threatening disease that resolves on its own without the need for treatment. The incidence is not potential for skin cancer and seldom causes discomfort while it leaves without long-term or lifelong effect on the skin. Lichen nitidus was once associated with lichen planus believed to be a variant but is now deemed a separate disease.
Causes
The exact cause of lichen nitidus has yet to be identified. At the moment, it is known that skin cells present an abnormal inflammatory activity, controlled by the white blood cells that are also known as lymphocytes. 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 the finger.
However, there are certain risk factors that the medical literature presents, as lichen nitidus may be associated with the following diseases:
- Lichen planus – at some point, it was believed that lichen nitidus is a variant of lichen planus. However, today, these are two separate entities and it seems that the existence of lichen planus is one of the risk factors involved in the appearance of lichen nitidus
- Atopic dermatitis – this is also an inflammatory skin condition, believed to favor the appearance of the skin-colored micropapules from lichen nitidus
- Crohn’s disease – this is also an inflammatory condition, affecting the interior lining of the digestive tract. As lichen nitidus can affect the mucous membranes from inside the body, people can certainly understand the connection between the two
- Juvenile rheumatoid arthritis – another inflammatory disease, affecting the joints of the body and predisposing to lichen nitidus
- Tuberculosis – infectious disease suppressing the immune system and favoring the appearance of other medical problems, including this inflammatory skin condition
- HIV infection – it has to do with a suppressed immune system as well
- Down syndrome – people with this genetic disorder present an increased risk for various skin conditions, including this one.
Symptoms
Lichen nitidus is hallmarked by the development of the tiny glistering papules that is skin-toned or may be hypopigmented in the individuals with dark skin. The affected area of the skin may also be noticed with slight scaling. Lichen nitidus is often asymptomatic although may get itchy. It is usually localized and seldom develops as generalized.
The tiny papules of lichen nitidus is referred to as lichen eruption and has various clinical variants such as –
- Generalized lichen nitidus rarely occurs in children and is an even rarer variant
- Hemorrhagic or purpuric lichen nitidus is characterized by an unusual eruption replicating a pigment purpuric papules and initially develop on top of the feet and around the ankle before it progresses to the legs until it become generalized
- Vesicular lichen nitidus is the blistering variant that is similar to a pompholyx and usually involves the palm of the hands
- Linear lichen nitidus is a variant of lichen nitidus that is arranged in line
- Keratodermic lichen nitidus involves the palms of the hands and soles of the feet and appears similar to fissuring in chronic eczema
- Perforated lichen nitidus is presented by umbilicated papules that usually develops in the forearms and hands
- Actinic lichen nitidus develops in the areas of the skin that are in constant exposure to the sun and is common among dark skinned individuals and the eruption of lesion is seasonal usually during the summer months
The papules or lesions of lichen nitidus is characterized by the following –
- The size of the papule is about 1mm to 2mm in diameter or similar to the size of a pinhead
- The shape of the lesion is round to polygonal
- The color of the papule is skin-tone and rarely yellowish or brownish while it may appear as hypopigmentation or hyperpigmentation in people with dark skin
- The top of the lesion is flat and the lesion appears shiny
- The lesion appears in clustered groups which may later merge to form a plaque
- The development of the lesion is usually localized and seldom occur as generalized
Lichen nitidus may also develop in the mouth and the papules are described as tiny and flat papules in gray-white color appearing inside the buccal mucosa. It develops on the tongue as white and hard plaques and resembles the appearance of lichen planus.
Lichen nitidus may also be seen with Koebner phenomenon which is not unusual. The lesion is rather arranged in linear down the scratch marks. The lesion of lichen nitidus may also involve the palm of the hand and sole of the foot which may develop in unilateral or bilateral or may occur as localized or in combination with other usual site of lichen nitidus.
Complications
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.
Treatment
Corticosteroids may reduce inflammation associated with lichen nitidus. The side effects vary depending on whether it’s used as an ointment applied directly to the skin (topical) or taken as a pill (oral). Long-term use of topical corticosteroids can cause thinning of the skin, a lessening of the treatment effect and other skin problems. Long-term use of oral corticosteroids can cause weakening of the bones (osteoporosis), diabetes, high blood pressure and high cholesterol levels.
Retinoid is a synthetic version of vitamin A that can be a topical or oral treatment. The topical treatment doesn’t cause the side effects associated with corticosteroids, but it may irritate the skin. Because retinoid can cause birth defects, it shouldn’t be used by women who are pregnant or who might become pregnant.
Other topical medications – A topical drug called tacrolimus (Protopic) helps to suppress the immune response and may be helpful for lichen nitidus. Possible side effects include stinging, burning and itching at the site where the medication is applied. This medication can’t be used in conjunction with phototherapy. Limit sun exposure while using tacrolimus and don’t use tanning beds during treatment.
Antihistamines act against a protein called histamine that is involved in inflammatory activity. An oral or topical antihistamine may relieve itching associated with lichen nitidus.
Phototherapy, a type of light therapy, may help clear up lichen nitidus. One type uses ultraviolet A (UVA) light, which penetrates deep into the skin. This therapy is usually used in combination with a drug that makes the skin more sensitive to UVA light.
Alternative Treatment
Vitamin A supplement helps skin stay healthy and boosts the immune system.
Omega-3 fatty acid supplement help reduce inflammation.
Zinc helps the immune system fight off bacteria and viruses. The lesions that develop are caused by inflammation from white blood cells called T-lymphocytes that are usually activated near the site of disease.
Vitamin C supplement strengthen the immune system and it is also important in promoting healthy skin.
Reference –
http://escholarship.org/uc/item/65p7c1s7
http://www.dermnet.com/images/Lichen-Nitidus
http://www.drugs.com/mcd/lichen-nitidus
http://emedicine.medscape.com/article/1123127-overview
http://www.dermnetnz.org/scaly/lichen-nitidus.html
http://www.fpnotebook.com/derm/hyperplasia/LchnNtds.htm
http://www.fortishealthcare.com/india/diseases/lichen-nitidus-665
http://healthh.com/lichen-nitidus/