Lichen simplex chronicus
Lichen simplex chronicus is a name given to a stubborn itchy rash that occurs in certain people with sensitive or irritable skin; it is also known as localized eczema. Lichen simplex, also called neurodermatitis, is a common skin problem. It generally affects adults, and may result in one, or many itchy patches.
Lichen simplex is a type of dermatitis, and is usually the result of repeated rubbing or scratching. The stimulus to scratch may be unrecognized, perhaps a mosquito bite, stress, or simply a nervous habit.The result is a very itchy patch of skin, often located on the nape of the neck, the scalp, the shoulder, the wrist, or the ankle. The genitals are less common sites. The affected skin is thickened, often appearing as a group of small firm papules (bumps). The skin markings are more visible, and the hairs are often broken-off. The colour may be darker or sometimes paler than the surrounding skin. Lichen simplex tends to be very persistent, and readily recurs despite often initially effective treatment.
Lichen simplex chronicus is a chronic inflammation of the skin (dermatitis) characterized by small, round itchy spots that thicken and become leathery as a result of scratching. Also termed neurodermatis, lichen simplex chronicus is the result of chronic skin irritation. It occurs in 4-5 out of every thousand people. Initial irritation causes itching, and in turn, itching causes scratching. Scratching leads to further irritation, which damages the skin. The possibility of infection is greatly increased when the outer layer of protective skin is broken. Skin usually repairs itself quickly; however, in the case of lichen simplex chronicus, healing skin causes more itching and more scratching causes a thickening of the skin (lichen). The small skin patches are usually 1–10 in (2.54–25.4 cm) in diameter.
Lichen simplex chronicus is often caused by constant rubbing of the skin. The rubbing begins the chain of events that leads from itching to scratching and then to the presence of leather-like skin patches. Symptoms are chronic itching which is often accompanied by nervous tension. The appearance of scratch marks and the leathery skin patches can be found anywhere on the body. A prolonged lichen simplex chronicus can result in brown-colored pigmentation at the site of irritation.
Treatment of the itching is necessary to stop the scratching and resulting skin damage. There are a number of ways to stop itching. Perhaps the most important is to cut fingernails very short. Ice can substitute for the relief of scratching. Heat and fuzzy clothing worsen itching; cold and smooth clothing pacify it. If the itching is persistent, dressings may be applied to the affected areas. Among the topical medications that relieve itching are a number of commercial preparations containing menthol, camphor, eucalyptus oil, and aloe. Topical cortisone is also available without a prescription. Some preparations also contain antihistamines, which penetrate intact skin poorly. All these medicines work better under occlusion, which means putting a waterproof barrier like a rubber glove or plastic wrap over them. For broken skin, topical antibiotics like bacitracin help prevent infection. These should be used early to forestall further damage to the skin.
Reducing the buildup of thick skin may require medicines that dissolve or melt keratin, the major chemical in skin's outer layer. These keratolytics include urea, lactic acid, and salicylic acid. Resistant cases of lichen simplex chronicus will often respond to cortisone-like drugs injected directly into the lesions. Sedatives or tranquilizers may be prescribed to combat the nervous tension and anxiety that often accompanies the condition.