Lichen simplex chronicus

Definition

Lichen simplex chronicus is a skin disorder that leads to chronic itching and scratching.

Causes, incidence, and risk factors

This disorder may occur in people who have:

• Eczema (atopic dermatitis)
• Psoriasis
• Nervousness, anxiety, depression, and other psychologic disorders

It is common in children, who cannot stop scratching insect bites and other itchy skin conditions. It can also be common in children who have chronic repetitive movements.

Symptoms

This skin disorder leads to a scratch-itch cycle:

• It may begin with something that rubs, irritates, or scratches the skin, such as clothing.
• This causes the person to rub or scratch the affected area. Constant scratching causes the skin to thicken.
• The thickened skin itches, causing more scratching, which causes more thickening.
• The skin may become leathery and brownish in the affected area.

Symptoms include:

• Itching of the skin
  • May be long-term (chronic)
  • May be intense
  • Increases with nervous tension, stress
• Skin lesion, patch, or plaque
  • Commonly located on the ankle, wrist, neck, rectum/anal area, forearms, thighs, lower leg, back of the knee, inner elbow
  • Exaggerated skin lines over the lesion
  • Distinct borders to the lesion
  • Becomes leathery in texture (lichenification)
  • Darkened (hyperpigmented) or reddened skin
  • Raw areas
  • Scratch marks
  • Scaling

Signs and tests

The diagnosis is primarily based on the appearance of the skin and a history of chronic itching and scratching. A skin lesion biopsy may be needed to confirm the diagnosis.

Treatment

The primary treatment is to stop scratching the skin. This may include counseling to become aware of the importance of not scratching, stress management, or behavior modification.

The itching and inflammation may be treated with a lotion or steroid cream applied to the affected area of the skin. Peeling ointments, such as those containing salicylic acid, may be used on thickened lesions. Soaps or lotions containing coal tar may be recommended.

Dressings that moisturize, cover, and protect the area may be used with or without medication creams. They are left in place for a week or more at a time.

Antihistamines, sedatives, or tranquilizers may be needed to reduce itching and stress. Steroids may be injected directly into lesions to reduce itching and inflammation.

Patients who have an emotional component to their lichen simplex chronicus may need antidepressants and tranquilizers.

Expectations (prognosis)

You can control lichen simplex chronicus by reducing stress and scratching less. The condition may return or change sites.

Complications

• Bacterial skin infection
• Permanent changes in skin color
• Permanent scar

Calling your health care provider

Call your health care provider if:

• Symptoms get worse
• You develop new symptoms, especially signs of skin infection such as pain, redness or drainage from the lesion, or fever

References

Habif TP. Ezcema and hand dermatitis. In: Habif TP, ed. Clinical Dermatology. 5th ed. St. Louis, Mo: Mosby Elsevier; 2009:chap 3.