Photo Rounds

Growths and darkened skin

A 55-year-old man presented to his family physician (FP) with growths and darkened skin on his neck. His medical history was significant for diabetes and obesity, which his FP had been following. The patient had not been able to lose weight, but was disturbed by the changes to the skin on his neck. He was taking metformin and his hemoglobin A1c was 7.8.

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Based on the dark velvety skin on the patient’s neck, the FP diagnosed acanthosis nigricans accompanied by multiple skin tags (acrochordons). The patient told the physician that he wanted to have the skin tags removed and the darkened skin treated. Because both conditions are associated with obesity and diabetes, the FP recommended that the patient increase his weight loss efforts through improved diet and increased exercise.

The FP also explained that treatment options for the skin tags included cryotherapy, snip excisions, and electrosurgery. The patient did not want to wait for the skin tags to fall off after cryotherapy or electrosurgery, so he chose snip excisions for immediate results. The skin tags were pedunculated with narrow stalks, so the snip excisions were performed without anesthesia. Aluminum chloride was applied to stop the bleeding on some of the skin tags. The patient noted some stinging, but tolerated the treatment well.

For the acanthosis nigricans, the FP explained that there are no highly effective treatments. In addition to recommending weight loss, the FP prescribed topical tretinoin cream 0.025% to be applied to the darkened skin before bed (only after the cuts from the skin tag removals had healed). The FP told the patient that the treatment might be only partially beneficial (or might not work at all). Other treatment options for acanthosis nigricans (with limited effectiveness) include keratolytic agents (eg, salicylic acid, ammonium lactate) and topical vitamin D analogs. At follow-up one month later, the patient had not yet noticed any changes to the acanthosis nigricans, but he was satisfied with the results of the skin tag removal.

Photos and text for Photo Rounds Friday courtesy of Richard P. Usatine, MD. This case was adapted from: Smith AM. Skin tags. In: Usatine R, Smith M, Mayeaux EJ, et al, eds. Color Atlas of Family Medicine. 2nd ed. New York, NY: McGraw-Hill; 2013: 922-925.

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