DISCUSSION
Lichen simplex chronicus (LSC), previously known as neurodermatitis, is quite common but frequently misdiagnosed. Patients often report that their condition started with a bug bite or poison ivy—a provocation that gets the patient in the habit of scratching, which continues long after the initial outbreak has subsided. Thus, LSC is often associated with significant chronicity, as typified by this case.
What patients seldom understand is their own role in the perpetuation of their condition. The urge to scratch is so unbearable that few can resist it. Over time, the scratching creates more nerves that have a lower threshold for itching, and thus the itch-scratch-itch cycle is born. Many LSC patients are atopic, which predisposes them to itching in general and to xerosis especially.
The literature asserts that LSC affects the genders equally, but this ignores the fact that it can present significantly differently in men and women. This patient’s area of involvement is quite typical for men, most of whom never moisturize and for whom the lateral calf is readily accessible. In the author’s experience, the most common location for LSC in women is the nuchal scalp, where heat and sweat appear to play a role, along with ready accessibility to fingernails or the sharp end of a pencil. Other common areas of involvement include the dorsal forearms and the scrotum or vulvae.
Biopsy is seldom necessary, but if performed, it will show a marked thickening of the epidermis, orthokeratosis (normal keratinocytes about to shed), and compacted, elongated rete ridges. These and other changes effectively rule out other items in the differential (eg, psoriasis, simple eczema, fungal infection).
Stopping the itch-scratch-itch cycle with mid-strength topical steroid creams or foams is the first step in treating LSC. But then the patient must be convinced of his contribution to the treatment: leaving the affected sites alone. Truth be told, after 20 years of scratching, the best this patient can look forward to is some relief—not only from the itching, but also from concern about all the terrible things he now knows he doesn’t have.
TAKE-HOME LEARNING POINTS
- Lichen simplex chronicus is quite common in both genders and is typified by longstanding severe itching, usually confined to one area.
- Atopy, xerosis, and stress all appear to contribute to the problem.
- Stopping the itch-scratch-itch cycle with topical steroids is a key component of treatment.
- Patient education—on the nature of the problem and the patient’s role in controlling it—is just as important as any prescribed medication.