Photo Rounds

Rash on arm

A 55-year-old man asked his family physician (FP) to look at a “rash” that had developed on his arm 3 months earlier. He said that it itched and was uncomfortable at times. He had no history of eczema or skin cancer. He had fair skin and worked as a welder.

What’s your diagnosis?


Rash on arm

The FP looked closely at the so-called rash and realized that while it could be nummular eczema it could also be a superficial basal cell carcinoma (BCC).

He explained the differential diagnosis to the patient and suggested that he perform a shave biopsy that day. The patient consented to the biopsy, and the physician numbed the area with 1% lidocaine and epinephrine. He used a DermaBlade and obtained hemostasis with aluminum chloride in water. (See the Watch & Learn video on “Shave biopsy.”) The biopsy result confirmed the FP’s suspicion: The lesion was a superficial BCC.

On the follow-up visit the FP explained the options for treatment, including electrodesiccation and curettage, cryosurgery, or an elliptical excision. He told the patient that the cure rates are about the same, regardless of which of these treatments were chosen. He also explained that either of the 2 destructive methods could be performed immediately, whereas the elliptical excision would require scheduling a longer appointment.

The patient chose the cryosurgery. (See the Watch & Learn video on cryosurgery.) After numbing the area with 1% lidocaine and epinephrine, the physician froze the lesion with a 3 mm halo for 30 seconds using liquid nitrogen spray. At follow-up 3 months later, there was some hypopigmentation, but no evidence of the BCC.

Photos and text for Photo Rounds Friday courtesy of Richard P. Usatine, MD. This case was adapted from: Karnes J, Usatine R. Basal cell carcinoma. In: Usatine R, Smith M, Mayeaux EJ, et al. Color Atlas of Family Medicine. 2nd ed. New York, NY: McGraw-Hill; 2013:989-998.

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