Leprosy in a Midwestern Dermatology Clinic: Report of 9 Patients

To describe the clinical features and epidemiology of leprosy in patients evaluated in a Midwestern dermatology clinic.

We performed a retrospective review of clinical and laboratory data from patients with leprosy who were evaluated in the Department of Dermatology at Mayo Clinic in Rochester, Minnesota, from January 1, 1994, through December 31, 2017.

Nine patients, 7 male and 2 female, were identified, ranging in age from 15 to 63 years (mean age, 38 years). Six of the 9 patients (67%) were foreign-born: 3 from Oceania (2 from Micronesia and 1 from Guam), 1 from Southeast Asia (Indonesia), and 2 from Mexico. Three patients were born in the United States. All 9 patients presented with skin lesions (granulomatous histopathologic type), and 8 had neuropathy. Leprosy was multibacillary in 8 patients and paucibacillary in 1. Two patients experienced a type 1 treatment reaction, and 5 had type 2 reactions. Three of the 9 patients had speciation by polymerase chain reaction (Mycobacterium leprae in 2 and Mycobacterium lepromatosis in 1).

Despite its rarity in the United States, leprosy should be considered in the differential diagnosis when evaluating both foreign- and US-born patients with granulomatous dermatitis and peripheral neuropathy. Because M lepromatosis was not identified until 2008 and requires polymerase chain reaction for diagnosis, the incidence of this species among patients with leprosy diagnosed in earlier years is unknown.