Lichen simplex chronicus (LSC) is a lichenified well-demarcated scaly plaque that is induced by chronic rubbing and/or scratching. Lichenification refers to thickened skin with enhanced skin markings that occurs as a result of friction from excessive scratching and rubbing. Co-existing papules may also be observed (prurigo nodularis), as may excoriations, which can become secondarily infected. As these plaques are self-induced, LSC is almost always found on areas that are within hand's reach, most commonly on the back of the head and neck in women and in the genital (scrotum and perineum) area in men. The lower aspect of the lateral shin is another site that is frequently involved. LSC is more common in women and middle-aged to elderly patients.
Itch from a variety of causes induces individuals to chronically scratch or rub their skin. LSC is commonly observed in uncontrolled atopic dermatitis and other forms of eczema, and in other dermatoses that have pruritus as a feature (eg, insect bites, scabies). When LSC is observed on relatively normal skin with no obvious underlying cutaneous (or systemic) precipitants, psychological factors are thought to play a significant role. In either case, an itch-scratch cycle is initiated, and if allowed to continue unabated, plaques of LSC inevitably develop.
Lichen simplex chronicus (LSC), also known as neurodermatitis circumscripta, is an itchy skin condition causing thickened skin at the areas of skin injured by repeated scratching and rubbing. Lichen simplex chronicus is not a primary disease but rather the skin's response to chronic physical injury (trauma). The gradual thickening of skin, caused by repetitive scratching and rubbing, is called lichenification.
Lichen simplex chronicus begins as itchy skin. The itching leads to scratching and rubbing, which causes thickening of skin. The thickened skin is itchy, which causes more scratching and, thus, more skin thickening. This scratch-itch cycle continues if not treated.
Who’s At Risk
Lichen simplex chronicus can occur in people of any age, of any race, and of either sex. However, it is more common in females than in males and appears more frequently in middle-aged and older adults.
Conditions that can lead to lichen simplex chronicus include:
Insect bites
Scars
Eczema (atopic dermatitis)
Dry skin (xerosis)
Poor circulation in legs (venous insufficiency)
Anxiety and stress
Signs & Symptoms
Although it can occur anywhere on the body, lichen simplex chronicus is most commonly seen in the following areas:
Inner wrists, forearms, and elbows
Sides and back of neck
Upper thighs, knees, shins, ankles, and tops of feet
Vulva, scrotum, anus (anogenital areas)
Scalp
Each patch of lichen simplex chronicus appears as leathery, thickened skin in which the normal skin lines are exaggerated. The thickened skin is darker than surrounding skin (hyperpigmented). This darkening is even more apparent in dark-skinned people.
Individuals with lichen simplex chronicus report periodic itching that is most intense at night or any time they are still.
Self-Care Guidelines
The primary treatment is to stop scratching. However, this can be very difficult once a scratch-itch cycle has started. Areas of lichen simplex chronicus may need to be covered at night, as many people scratch in their sleep.
Use moisturizers to help relieve itchy skin. When choosing a moisturizer, look for oil-based creams and ointments, which work better than water-based lotions. Apply moisturizers just after bathing, while the skin is still moist.
Apply over-the-counter hydrocortisone cream to decrease the itch. However, if the itching is limited to the groin area, you may have a fungal infection (jock itch [tinea cruris]) rather than lichen simplex chronicus. Do not apply hydrocortisone to the groin area unless recommended to do so by a doctor.
If there are breaks or cracks in the skin, apply an antibiotic ointment to prevent infection.
When to Seek Medical Care
See your doctor if the itching does not improve with self-care measures, if you are developing more lesions, or if you develop symptoms of infection such as pain, redness, drainage of pus, or fever.
Treatments
If your doctor is not sure if you have lichen simplex chronicus, he/she may wish to perform a skin biopsy to confirm the diagnosis. The procedure involves:
Numbing the skin with an injectable anesthetic.
Sampling a small piece of skin by using a flexible razor blade, a scalpel, or a tiny cookie cutter (called a "punch biopsy"). If a punch biopsy is taken, a suture or two may be placed and will need to be removed 6-14 days later.
Having the skin sample examined under the microscope by a specially trained physician (dermatopathologist).
Once you are sure you have lichen simplex chronicus, it is important to break the scratch-itch cycle. In addition to the above self-care measures, your doctor may recommend one or more of the following treatments to reduce itching and scratching:
Aggressive moisturizing techniques
Corticosteroid (cortisone) creams or ointments
Creams containing salicylic acid or urea, to improve penetration of the topical corticosteroid
Oral anti-histamines, especially for use at bedtime
Injection of corticosteroid solution directly into the lichen simplex chronicus lesions
Ultraviolet light therapy
Sedatives or anti-depressants for people with lichen simplex chronicus strongly related to psychological stress
Doxepin or capsaicin cream
Topical or oral antibiotics if infection is present
References
Bolognia, Jean L., ed. Dermatology, pp.117-118. New York: Mosby, 2003.
Patient Information for Lichen simplex chronicus in Adult