The FP did a 4-mm punch biopsy to confirm that this was a case of prurigo nodularis and prescribed clobetasol cream to be applied twice daily to the pruritic nodules. The FP recommended that the patient apply the cream instead of scratching the area. The FP also said that if the patient couldn’t avoid touching the area, it would be better to lightly rub the area over his clothing instead.
The biopsy results subsequently confirmed a diagnosis of prurigo nodularis. At the patient’s 2-week follow-up, he indicated that his symptoms were 50% better since using the clobetasol. The FP explained to the patient the nature of prurigo nodularis, including the patient’s itch-scratch cycle and how stress was making it worse. The patient acknowledged that his symptoms had become worse when he began having financial trouble. The FP asked the patient if he wanted to see a counselor, but the patient declined, saying that he just needed to get more work.
At a one-month follow-up, 90% of the nodules were resolved, although there were still some stubborn areas that continued to itch. The patient could not control scratching these areas at times. The FP offered intralesional injections with triamcinolone and/or cryotherapy. The patient consented to liquid nitrogen therapy and the remaining nodules were frozen for approximately 10 seconds each using a liquid nitrogen spray.
Four weeks later, the patient had 4 remaining nodules. The FP injected the nodules with 10 mg/mL triamcinolone and refilled the clobetasol cream. At the next appointment, 2 nodules remained. The patient indicated that he would continue using the cream until the nodules went away. In many cases, prurigo nodularis does not respond especially well to treatment, so this patient was fortunate that standard treatments provided a good outcome.
Photos and text for Photo Rounds Friday courtesy of Richard P. Usatine, MD. This case was adapted from: Usatine R, Johnson A. Self-inflicted dermatosis. In: Usatine R, Smith M, Mayeaux EJ, et al, eds. Color Atlas of Family Medicine. 2nd ed. New York, NY: McGraw-Hill; 2013: 856-862.
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