Herpes Zoster with Contact Dermatitis Developing under a Patch

A 41-year-old man presented with worsening left lower back pain and pruritus. He attributed the pain to heavy lifting three days previously and had applied a transdermal nonsteroidal anti-inflammatory drug (NSAID) patch. A physical examination revealed erythema in the shape of the patch, with a cluster of vesicular lesions in the center and to the left of the erythema (Picture). The Tzanck test confirmed herpes zoster with contact dermatitis. The NSAID patch was removed. He was treated with oral acyclovir, and the pain and rash resolved after two weeks. Physicians may omit a skin examination for back pain if it is attributed to physical strain, thereby missing hidden herpes zoster, which is often misdiagnosed because of the delayed onset of the typical rash (1) and musculoskeletal pain before the onset. In patients with back pain, removing any applied NSAID patch and performing a direct visual examination of the skin is essential for making a correct diagnosis.

Picture.

The authors state that they have no Conflict of Interest (COI).

Financial Support

This work was supported by the Japan Medical Education Foundation (https://www.jmef.or.jp/). The funders had no role in the preparation of the manuscript or decision to publish.