DISCUSSION
Lichen simplex chronicus (LSC) is the term given to this phenomenon. LSC is always secondary to a primary trigger, which can be dry skin, eczema, psoriasis, or even a bug bite. Excessive scratching induces more itching, and before the patient realizes it, he has jumped aboard the itch-scratch-itch train—a vicious cycle that can be hard to break.
The skin reacts to all this attention by thickening and becoming rough; on a microscopic level, the nerves become more sensitive. The urge to scratch becomes so irresistible that some patients fantasize about giving in.
The first goal of treating LSC is to stop the itching by helping the patient avoid contact with the site. High-potency topical steroids can be effective for this, especially if used under occlusion, which not only potentiates the steroid but also provides a barrier to protect the area from the patient’s fingernails (or hairbrush). Once the condition improves, steroids can be slowly withdrawn.
A biopsy, if it had been necessary, would have shown hypertrophic epidermis and acanthotic changes.
TAKE-HOME LEARNING POINTS
• Lichen simplex chronicus (LSC) is secondary to an inciting condition such as eczema, xerosis, psoriasis, or Darier disease.
• The manifestation of the itch-scratch-itch cycle leads to thickening and lichenification of the skin. The itch of LSC is so compelling that scratching is hard to resist.
• Despite treatment and patient education, recurrences are quite common.