A Hyperpigmented Patch That Remains Despite Washing With Soap and Water

Authors:
Alexander K. C. Leung, MD; Benjamin Barankin, MD; Amy A. M. Leung, MD; and Joseph M. Lam, MD

Citation:
Leung AKC, Barankin B, Leung AAM, Lam JM. A hyperpigmented patch that remains despite washing with soap and water. Consultant. 2018;58(11):309-312,315.

An 8-year-old girl presented with a 1-year history of an asymptomatic, reticulated, hyperpigmented patch on the anterior neck, over the jugular notch. The hyperpigmented patch was very slowly expanding. The patient was unable to remove this with regular washing using soap and water. She had not received any medical treatment for this issue. Her past health was unremarkable, and she was not on any topical or oral medications. There was no history of rapid weight gain. She denied any history of inflammatory dermatoses prior to the appearance of this dark patch. The family history was noncontributory, with no history of diabetes mellitus or autoimmune diseases.

On physical examination, the child had a reticulated hyperpigmented patch on the anterior neck, superior to the jugular notch (Figure 1). Her height was 126 cm (50th percentile) and her weight was 27.5 kg (75th percentile). The rest of the physical examination findings were unremarkable.

Dermoscopy revealed large, polygonal, platelike, brown scales in a mosaic pattern.

The patch was completely removed after vigorous rubbing using a 70% isopropyl alcohol swab (Figure 2). A brownish stain was seen on the alcohol swab after the rubbing was performed (Figure 3).

Answer and discussion on next page.