That the case patient was a recent immigrant from a country with a high incidence of HD, coupled with a loss of sensation in his extremities, led to the correct diagnosis. His lack of response to antifungals or anti-inflammatory agents, though frustrating to both patient and provider, was helpful in excluding two common conditions in the differential diagnosis. Other possibilites that were considered ultimately did not ring true:
Vitiligo, a loss of pigment that produces white patches resembling borderline leprosy but lacks the raised edging18;
Granuloma annulare, a lightly raised, ring-shaped lesion that is usually found on the extremities19; and
Lupus erythematosus, in which patients almost universally experience pruritus and burning, whereas lack of sensation is key to a diagnosis of leprosy.20
Treatment and Management
Health care providers must appear confident to instill confidence in their patients. Any provider with the knowledge and acuity to make a diagnosis of leprosy should be adequately equipped to manage the patient’s care. However, the hesitant or uncertain provider should consider referral to dermatology or to infectious disease for continued management.
The NHDP recognizes the WHO classification of leprosy as multibacillary or paucibacillary (observing a “simple clinical rule” of six or more lesions representing multibacillary HD and five or fewer, paucibacillary HD1), with additional consideration to the three major disease subtypes mentioned earlier: TT, which is treatable; BB, which is considered unstable; and LL, which is resistant to treatment. NHDP and WHO recommendations for treatment differ slightly but address the same goals: complete elimination of the pathogen, preservation of muscle and nerve function, prevention of secondary infections, and management of the adverse effects of medication.1,21 Adhering to universal precautions is important.
In the US, the multidrug treatment regimen for paucibacillary (TT or BT) leprosy comprises one year of oral rifampin 600 mg/d and oral dapsone 100 mg/d21; WHO, in deference to cost containment in developing countries, recommends a six-month regimen of these agents (ie, rifampin 600 mg/mo and dapsone 100 mg/d).1 A third drug sometimes given to allay active neuritis is oral clofazimine 50 mg/d for one year21 (per WHO recommendations, a monthly dose of 300 mg, plus 50 mg/d1). In patients with preexisting or subsequent anemia, dapsone dosing should be lowered to 50 mg, the minimally effective level. Of note, clofazimine is no longer commercially available in the US and is held by the NHDP as an investigational new drug for treatment of US patients.21
According to US recommendations,21 use of this three-agent regimen is extended to two years for patients with multibacillary (LL, BL, BB) leprosy. For these patients, WHO recommends its regimen for 12 months.1
Rifampin is a powerful antibiotic used for effective treatment of tuberculosis, methicillin-resistant Staphylococcus aureus, gonorrhea, Listeria, and Haemophilus influenzae. However, its use has been shown to reduce the efficacy of anticoagulants, oral contraceptives, and prednisone, possibly requiring therapeutic adjustments.22 Recommended alternatives for rifampin include (in the order of preference) minocycline 100 mg/d, ofloxacin 400 mg/d, levofloxacin 500 mg/d, or twice-daily clarithromycin 500 mg.13
Patient compliance with the regimen is facilitated by convenient blister packs that contain standard weekly and monthly doses of these medications, all clearly marked. Many local health departments make these medications available at no cost to patients.
Patient Education
Informing patients what to expect regarding their medications, necessary lab work, and avoiding transmission of HD can ease worry, protect others from illness, and increase the likelihood of an excellent prognosis. Patients with lepromatous (multibacillary) HD should be urged to limit their interactions with others at work or school (particularly preventing exposure to their nasal excretions) until a low bacterial index is achieved. For close contacts of patients recently diagnosed with HD, single-dose rifampin has been shown to provide effective prevention for two years.23
Emphasizing adherence to daily multidrug therapy minimizes the chance that bacterial resistance will develop. Patients should be given complete information about the individual agents used:
Rifampin 600 mg is the maximum daily dose for an adult. Hepatotoxicity is a concern, and liver enzyme levels (ie, aspartate aminotransferase, alanine aminotransferase) should be measured at three-month intervals. It is important to obtain a history of previous liver disease, exposure to hepatitis, and drug and alcohol use. In otherwise healthy adults, rifampin has the curious effect of turning bodily fluids such as urine and tears bright red. Forewarning patients of this benign development may prevent anxious reactions. Contact lenses may be irreversibly stained.24
Dapsone, for many years the first-line monotherapy for leprosy, is a bacteriostatic, sulfa-based antibiotic that only prevents the multiplication of bacteria, but it is still worthy of respect. Before dapsone is initiated, a screening test for glucose-6-phosphate dehydrogenase deficiency should be performed to determine the risk for dapsone-associated hemolysis.24 Dapsone use is contraindicated in women who are breastfeeding. In patients with severe heart conditions, dapsone can reduce oxygen flow, as evidenced by a bluish discoloration of the lips and fingertips. Mild anemia, headache, gastrointestinal upset and nausea are all common adverse effects.