2. A 34-year-old patient reports excruciating itching, with disruption of daily activities and sleep. She has been treated for candidiasis on multiple occasions, but her wet mount and confirmatory culture are negative. Physical exam reveals a pink, lichenified plaque with excoriation.
Diagnosis: Lichen simplex chronicus (formerly called squamous hyperplasia or hyperplastic dystrophy, and also known as eczema, neurodermatitis, or localized atopic dermatitis) occurs when irritation from any cause produces itching in a predisposed person. The subsequent scratching and rubbing both produce the rash and exacerbate the irritation that drives the itching, even after the original cause is gone. The rubbing and scratching perpetuate the irritation and itching, producing the “itch-scratch” cycle.
The appearance of lichen simplex chronicus is produced by rubbing (where the skin thickens and lichenifies) or scratching (where the skin becomes red with linear erosions, called excoriations, caused by fingernails).
For more information on this case, see “Chronic vulvar symptoms and dermatologic disruptions: How to make the correct diagnosis.” OBG Manag. 2014;26(5):30-49.