Lichen simplex chronicus (LSC) is also known as neurodermatitis. This term refers to a chronic itchy condition of the skin that appears to get worse with scratching. This scratching leads to the skin becoming leathery and thick. LSC is not contagious and it is a fairly benign disorder.
The lesions associated with LSC may appear on several areas of the body, including the neck, shoulders, forearms, wrists, vulva, thighs and ankles. The characteristic lesion of LSC is a plaque that is lichenified due to excessive scratching. The scratch-itch cycle is typically a self-perpetuating one. The initial stimulus leads to scratching, that results in thickening of the skin.
The chronic inflammation set up by the pressure of the increased thickness of the cornified layer of the skin on the more fragile layers below leads to more itching, that causes even more scratching.
Pathogenesis of LSC
The exact causative mechanisms of LSC are unknown, but several studies have indicated that there may be some key triggers. The proposed precipitating factors include:
- Insect bites
- Nerves in the skin that are hypersensitive to certain stimuli that cause itching sensations.
In addition to the suggested triggers, neurodermatitis appears to be associated with certain other skin conditions. Skin diseases such as psoriasis, eczema and dry skin have all been implicated in the pathogenesis. Individuals with a personal or family history of such conditions have an increased predisposition to developing LSC, especially if they are females, between the third and fifth decades of life.
Symptoms of LSC
LSC produces symptoms such as:
- Itching which persists and often increases in stressful situations
- Raw areas of skin due to excessive scratching
- Scaling of the skin in the affected area
- Lesions consisting of patches or plaques of skin which are sharply marked out from the neighboring area, leathery in texture
LSC and the quality of life
The itching that occurs in LSC may be so intense that it disrupts the individual’s quality of life. It is particularly likely to affect sleep and normal sexual functions. Approximately 12% of the population is affected by the condition. It has a higher prevalence among women. The accompanying psychosocial burden of the disease manifests primarily as anxiety, depression, nervousness and other psychological disorders. These psychological problems lead to negative emotional states, as well as poor interpersonal and social skills. These patients are also reportedly plagued by sleep disturbances and sexual dysfunctions.
Complications of LSC
LSC may cause complications such as hyper- or hypopigmentation of the skin, bacterial infections of the skin broken by scratching, and scarring of the skin.
Management of neurodermatitis
The obvious primary step in tackling LSC is breaking the scratch-itch cycle. In other words, the patient needs to refrain from the urge to rub or scratch the areas that are affected. In instances where the itch is irresistible, gloves and socks may be used as occlusive measures. Counseling and psychotherapy may be required. Stress reduction techniques may also help.
Any offending agent or precipitating factors will have to be identified and removed in order to eliminate the itch stimulus. If the allergen is hard to identify, allergy tests may be employed to assist in the identification of the culprit substance. Furthermore, patients are encouraged to keep their fingernails clipped as short as possible. This is to avoid secondary bacterial infections that may result as a complication of introducing bacteria from under the nails into the skin that is broken by scratching.
Further therapy involves the use of moisturizing creams that have a soothing and protective effect on the skin. Topical corticosteroids may be used to relieve the itching and inflammation when necessary. However, their use should be limited to short periods due to their side effects. Other agents that may be used to treat the condition include topical calcineurin inhibitors and non-corticosteroids such as tacrolimus. Antihistamines or sedatives may be of help in controlling the itching in the initial period.
LSC tends to be a chronic condition, but the prognosis for many of those who are affected is good, provided that the affected areas of skin is treated with appropriate topical agents and allowed time to heal. In addition, protective measures should be continued to avoid recurrences.
Reviewed by Dr Liji Thomas, MD.