Diagnosis and Treatment of Leprosy Type 1 (Reversal) Reaction

Leprosy is a chronic granulomatous infection caused by the organism Mycobacterium leprae that primarily affects the skin and peripheral nerves.¹ The organism is thought to be transmitted from person to person via the nasal secretions of infected individuals and is known to have a long incubation period, lasting 2 to 6 years.² Leprosy has several distinct clinical presentations depending on the host immune response to the infection.³ Treatment typically involves antimicrobials (eg, clofazimine, dapsone, rifampin). Once treatment has begun, an important aspect of patient care is the recognition and treatment of leprosy reactions. Leprosy reactions are acute inflammatory complications that typically occur during the treatment course but also may occur in untreated disease. Type 1 (reversal) and type 2 (erythema nodosum leprosum) reactions are the 2 main types of leprosy reactions, which may affect 30% to 50% of all leprosy patients combined.⁴ Vasculonecrotic reactions (Lucio leprosy phenomenon) in leprosy are much less common.

We report a case of a 44-year-old man who repeatedly developed physical findings consistent with type 1 reactions after undergoing multiple treatments for leprosy. A discussion of leprosy, as well as its clinical manifestations, treatment options, and management of reversal reactions, also will be provided.

Case Report

A healthy 44-year-old man presented with a several month history of elevated, erythematous to yellow, anesthetic papules and plaques on the trunk (Figure 1). No other systemic symptoms were noted. Biopsies of multiple skin lesions showed noncaseating granulomas with preferential extension in a perineural pattern and tracking along the arrector pili muscle (Figure 2). The cutaneous nerves appeared to be slightly enlarged. The patient reported a history of living in Louisiana and growing up with armadillos in the backyard, often filling the holes that they dug, but he denied having direct contact with or eating armadillos. In childhood, the patient traveled across the border to Mexico a few times but only for the day. He spent several months in the Middle East (ie, Diego Garcia, Saudi Arabia) more than 10 years prior to presentation, and he spent 2 weeks in Korea approximately 2 years prior to presentation but did not travel off the US air base. He had never traveled to South America or Africa. The clinical and histopathologic findings were consistent with Hansen disease (leprosy) and were determined to be tuberculoid in type given the limited clinical presentation, tuberculoid granulomas on biopsy, and no visible organisms on histopathologic analysis.

Figure 1. Granulomatous cutaneous reversal reaction on the trunk. Figure 2. Photomicrograph demonstrating a dermal infiltrate of noncaseating granulomas composed of epithelioid histiocytes, lymphocytes, and giant cells with a perineural granuloma (arrow)(H&E, original magnification ×200).

The patient initially was started on rifampin but was unable to tolerate treatment due to subsequent hepatotoxicity. He then was transitioned to a dual regimen of clofazimine and dapsone, which he tolerated well for the full 12-month treatment course. The cutaneous lesions quickly resolved after starting treatment, leaving a fine “cigarette paper–like” atrophy of the skin. After 12 months, it was subsequently presumed that the patient’s disease had been cured and treatment was stopped.

Nine months later, the patient noted new papules and plaques beginning to reappear in the truncal region. He was seen in clinic and a repeat biopsy was conducted, revealing perineural inflammation and noncaseating granulomas that were similar to the initial biopsies. Fite staining showed no acid-fast bacilli. Polymerase chain reaction was negative for M leprae. Nevertheless, a diagnosis of recurrent leprosy was made based on the patient’s clinical manifestations. He initially was started on dapsone, minocycline, and levofloxacin but was unable to tolerate the minocycline due to subsequent vertigo. After 1 month of treatment with dapsone and levofloxacin, the patient was clinically clear of all skin lesions and a repeat 12-month course of treatment was completed.

One year after completing the second 12-month treatment course, the patient again developed recurrent, indurated, erythematous papules and plaques on the trunk. Expert consultation from the National Hansen’s Disease (Leprosy) Program determined that the patient was experiencing a type 1 (reversal) reaction, not recurrent disease. Intralesional triamcinolone acetonide (10 mg/cc) was subsequently administered within the individual lesions. After a few treatments, the patient experienced notable regression of the lesions and has since been free of recurrent reactions (Figures 3 and 4).

Figure 3. Notable regression was seen 4 weeks after intralesional triamcinolone acetonide injection to the truncal plaque. Figure 4. Macular atrophy was noted after the truncal lesion resolved.

Comment

Mycobacterium leprae

Mycobacterium leprae is an obligate intracellular bacillus that is confined to humans, armadillos of specific locales, and sphagnum moss. It is an acid-fast bacillus that is microscopically indistinguishable from other mycobacteria and is best detected on Fite staining of tissue sections.⁵