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Infectious Diseases > MEDICAL TOPICS
Leprosy
Article Last Updated: Jul 24, 2006
AUTHOR AND EDITOR INFORMATION
Section 1 of 10
Author: D Scott Smith, MD, MSc, DTM&H, Adjunct Assistant Professor, Department of Microbiology and Immunology, Stanford University; Chief of Infectious Diseases and Geographic Medicine, Department of Internal Medicine, Kaiser Redwood City Hospital
D Scott Smith is a member of the following medical societies: American Medical Association, American Society of Tropical Medicine and Hygiene, Infectious Diseases Society of America, and International Society of Travel Medicine
Coauthor(s):
Tara Ramachandra, BS, Stanford University School of Medicine
Editors: Fred A Lopez, MD, Vice-Chair, Department of Internal Medicine, Division of Infectious Diseases, Assistant Professor, Louisiana State University School of Medicine; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Charles V Sanders, MD, Edgar Hull Professor and Chairman, Department of Internal Medicine, Professor of Microbiology, Immunology and Parasitology, Louisiana State University School of Medicine at New Orleans; Medical Director, Medicine Hospital Center, Charity Hospital and Medical Center of Louisiana at New Orleans; Consulting Staff, Ochsner Medical Center; Eleftherios Mylonakis, MD, Clinical and Research Fellow, Department of Internal Medicine, Division of Infectious Diseases, Massachusetts General Hospital; Burke A Cunha, MD, Professor of Medicine, State University of New York School of Medicine at Stony Brook; Chief, Infectious Disease Division, Winthrop-University Hospital
Author and Editor Disclosure
Synonyms and related keywords:
Hansen's disease, Hansen disease, Mycobacterium leprae, M leprae, tuberculoid leprosy, TT leprosy, lepromatous leprosy, LL leprosy, BT leprosy, midborderline leprosy, BB leprosy, borderline lepromatous leprosy, BL leprosy, paucibacillary leprosy, PB leprosy, multibacillary leprosy, MB leprosy
Background
Leprosy is a chronic infection caused by the acid-fast, rod-shaped bacillus Mycobacterium leprae. Leprosy can be considered 2 connected diseases that primarily affect superficial tissues, especially the skin and peripheral nerves. First, a mycobacterial infection causes a wide array of cellular immune responses. These immunological events elicit the second part of the disease: a peripheral neuropathy with potentially long-term consequences. The social and psychological effects of leprosy, as well as its highly visible debilities and sequelae, have resulted in a historical stigma associated with leprosy (see Image 1). To minimize the prejudice against those afflicted with leprosy, the condition is also known as Hansen disease, named after G.A. Hansen, who is credited with the 1873 discovery of M leprae. This mycobacterium grows extremely slowly and has not been successfully cultured in vitro. In the 1990s, the World Health Organization (WHO) launched a campaign to eliminate leprosy as a public health problem by 2000. Elimination, as defined by the WHO, meant a reduction of the prevalence of patients with leprosy requiring multidrug therapy to fewer than 1 per 10,000 population. This goal was achieved in terms of global prevalence by 2002, but 15 of the 122 countries where leprosy was endemic in 1985 still have prevalence rates of greater than 1 per 10,000 population. Although multidrug regimens have been used globally to cure nearly 14 million patients since 1985, the number of new cases of leprosy remained relatively unchanged from 1980 to 2000, ranging from 500,000-700,000 worldwide per year. Access and delivery of antibiotics continues to be a problem in the most endemic nations. With the precise transmission mechanism still unknown and a lack of an effective vaccine, the disease will probably continue to pose an ongoing public health problem in the coming decades.
Pathophysiology
Leprosy can express itself in different forms, depending on the host response to the organism. Individuals who have a vigorous cellular immune response to the organism have the tuberculoid form of the disease that usually involves the skin and peripheral nerves. The number of skin lesions is limited, and they tend to be dry and hypoesthetic. Nerve involvement is usually asymmetric. This form of the disease is also referred to as paucibacillary leprosy because of the low number of bacteria in the skin lesions (ie, <5 skin lesions, with absence of organisms on smear). Results of skin tests with antigen from killed organisms are positive in these individuals. Individuals with minimal cellular immune response have the lepromatous form of the disease, which is characterized by extensive skin involvement. Skin lesions often are described as infiltrated nodules and plaques, and nerve involvement tends to be symmetric in distribution. The organism grows best at 27-30°C; therefore, skin lesions tend to develop in the cooler areas of the body, with sparing of the groin, axilla, and scalp. This form of the disease is also referred to as multibacillary leprosy because of the large number of bacteria found in the lesions (ie, > 6 lesions, with possible visualization of bacilli on smear). Results of skin tests with antigen from killed organisms are nonreactive. Patients may also present with features of both categories; however, over time, they usually evolve to one or the other (indeterminate or borderline leprosy). Interestingly, most individuals who are exposed to leprosy never develop the disease. Classification of leprosy: Leprosy has 2 classification schemas: the 5-category Ridley-Jopling system and the simpler and more commonly used WHO standard.
- Ridley-Jopling: Depending on the host response to the organism, leprosy can manifest itself clinically along a spectrum bounded by the tuberculoid (TT) and lepromatous (LL) forms of the disease. Most patients fall into the intermediate classifications, which include borderline tuberculoid (BT), midborderline (BB), and borderline lepromatous (BL). Typically, the classification of the disease may change as the disease evolves during its progression or management. The Ridley-Jopling system is used globally and forms the basis of clinical studies of leprosy. It may also be more useful in guiding treatment regimens and assessing risk of acute complications. Physical findings in each subtype are presented in the Clinical section.
- WHO system: The WHO recommends classifying leprosy according to the number of lesions and the presence of bacilli on a skin smear. This method is useful in countries where biopsy analysis in unavailable.
- Paucibacillary (PB) leprosy is characterized by 5 or fewer lesions with absence of organisms on smear. Paucibacillary leprosy generally includes the tuberculoid and borderline lepromatous categories from the Ridley-Jopling system.
- Multibacillary (MB) leprosy is marked by 6 or more lesions with possible visualization of bacilli on smear. Lepromatous, borderline lepromatous, and midborderline on the Ridley-Jopling scale are included in the multibacillary category.
Frequency
United States
An average of 150 cases are diagnosed each year, with 69 new cases detected and 131 prevalent cases in 2004, according to the WHO. Endemic foci exist in parts of Louisiana, Florida, and Texas along the Gulf of Mexico; in Mexican and Asian California populations; and in Spanish Americans in New York City. Around 85% of these detected cases involve patients who have lived in foreign countries, primarily Asia, Africa, and Latin America.
International
According to WHO figures, the global registered prevalence of leprosy at the start of 2005 was 286,063 cases. Global annual detection rates have declined from 2001 to 2004, when 763,262 and 407,791 new cases were reported, respectively. Leprosy is still deemed a public health problem in 9 countries: Angola, Brazil, Central African Republic, Democratic Republic of the Congo, India, Madagascar, Mozambique, Nepal, and the United Republic of Tanzania. These countries account for 84% of the detection rates. Furthermore, more than 94% of new cases in Latin America are reported in Brazil.
Mortality/Morbidity
Leprosy is rarely fatal, and the primary consequence of infection is nerve impairment and debilitating sequelae. According to estimates, 3 million people who have completed multidrug therapy have sustained disability due to nerve damage. Although both the lepromatous and tuberculoid forms of the disease involve the skin and peripheral nerves, the tuberculoid form of the disease has more severe manifestations. Nerve involvement results in loss of sensory and motor function, which may lead to frequent trauma and amputation. The ulnar nerve is most commonly involved.
- Damage in the following nerves is associated with characteristic impairments in leprosy:
- Ulnar and median - Clawed hand
- Posterior tibial - Plantar insensitivity and clawed toes
- Common peroneal - Foot drop
- Radial cutaneous, facial, and greater auricular nerves (may also be involved; see Image 2)
- Infiltration by bacteria may lead to destruction of nasal cartilage (lepromatous form), ocular involvement, and diffuse thickening of the skin. Advanced cases involve the loss of eyebrows and lashes, but these deformities are less common today.
- Worldwide, leprosy is considered the most frequent cause of crippling of the hand, which is caused by ulnar nerve involvement. Peroneal nerve involvement can lead to foot drop, posterior tibial nerve involvement, and claw toes.
Race
Leprosy was once endemic worldwide, and no racial predilection is known. In the late 1800s, the incidence of leprosy in northern Europe and North America dropped dramatically, and the disease is now reported primarily in tropical areas.
Sex
Leprosy is generally more common in males than in females, with a male-to-female ratio of 1.5:1. In some areas in Africa, the prevalence among females is equal to or greater than that in males.
Age
Leprosy can occur at any age, but, in developing countries, the age-specific incidence peaks in children younger than 10 years, who account for 20% of cases. Leprosy is very rare in infants; however, they have a relatively high risk of developing leprosy from the mother, especially in cases of lepromatous or midborderline disease.
History
- Symptoms
- Painless skin patch accompanied by loss of sensation but not itchiness (Loss of sensation is a feature of tuberculoid leprosy, unlike lepromatous leprosy, in which sensation is preserved; see Image 3.)
- Loss of sensation or paresthesias where the affected peripheral nerves are distributed
- Wasting and muscle weakness
- Foot drop or clawed hands (Image 4)
- Ulcerations on hands or feet (Image 5)
- Symptoms in reactions
- Type 1 (reversal) - Sudden onset of skin redness and new lesions
- Type 2 (erythema nodosum leprosum [ENL]) - Many skin nodules, fever, redness of eyes, muscle pain, and joint pain
- Clawed hands or foot drop - May result from neuritic pain and rapid peripheral nerve damage
- Travel: The diagnosis should be considered in anyone who has lived in the tropics or who has traveled for prolonged periods to endemic areas.
- Exposure
- The incubation period is long, ranging from a few months to 20-50 years. The mean incubation time is estimated to be 10 years for lepromatous and 4 years for tuberculoid leprosy. The organism's slow dividing time (once every 2 wk) contributes to the challenge of epidemiologically linking exposures to the development of disease.
- Because of immunologic reasons, only around 5-10% of the population is estimated to be susceptible to infection.
Physical
The cardinal signs of leprosy include hypoesthesia, skin lesions, and peripheral neuropathy. The first physical signs of leprosy are usually cutaneous. The subtype of leprosy often determines the degree of skin involvement.
- Physical examination should include the following:
- Evaluation of skin lesions
- Careful sensory and motor examination
- Palpation of peripheral nerves for pain or enlargement. Particular attention should be paid to the following locations:
- Elbows - Ulnar nerve
- Wrist - Superficial radial cutaneous and median nerves
- Popliteal fossa - Common peroneal nerve
- Neck - Great auricular nerve
- Physical findings in specific leprosy subtypes include the following:
- Tuberculoid leprosy
- The initial lesion is often a sharply demarcated hypopigmented macule that is ovoid, circular, or serpiginous. The lesions can be somewhat elevated with a dry scaly center and erythematous borders.
- Common lesion sites include the buttocks, face, or extensor surfaces of limbs. The perineum, scalp, and axilla are not normally involved because of the temperature differential in these zones, as predilection is toward cooler zones.
- As the disease progresses, lesions tend to destroy the normal skin organs such as sweat glands and hair follicles.
- Superficial nerves that lead from the lesions tend to enlarge and are sometimes palpable. The patient may experience severe neuropathic pain. Nerve involvement can also lead to trauma and muscle atrophy.
- Lepromatous leprosy
- This form is characterized by extensive bilaterally symmetric cutaneous involvement, which can include macules, nodules, plaques, or papules (see Image 6).
- Unlike lesions in tuberculoid leprosy, those in lepromatous leprosy have poorly defined borders and raised and indurated centers. As in all forms of leprosy, lepromatous lesions are worst on cooler parts of the body. Common areas of involvement include the face, ears, wrists, elbows, buttocks, and knees.
- Hoarseness, loss of eyebrows and eyelashes, and nasal collapse secondary to septa perforation may be seen in advanced cases of disease. Involvement of the eye may include keratitis, glaucoma, or iridocyclitis (see Image 7).
- The leonine facies associated with leprosy develop as the disease progresses, and the skin of the face becomes thickened and corrugated.
- Systemically, axillary and inguinal adenopathy may develop, in addition to scarring of the testes and subsequent gynecomastia and sterility.
- Nerve involvement is not as severe as in the tuberculoid form of the disease, since nerves, although visibly thickened and highly infected, still function reasonably well in early stages of the disease.
- Borderline tuberculoid leprosy: The lesions are few or moderate and asymmetric with almost complete anesthesia. Peripheral nerves are often involved and thickened asymmetrically, and cutaneous nerves are sometimes enlarged.
- Midborderline leprosy: The number of skin lesions is moderate, and they are asymmetrical and somewhat anesthetic. Peripheral nerves may be somewhat symmetrically enlarged, but cutaneous nerves are not.
- Borderline lepromatous leprosy: Moderate to numerous slightly asymmetrical skin lesions appear with minor or no anesthesia. Peripheral nerves are often enlarged symmetrically, but cutaneous nerves are not.
- Indeterminate leprosy: Skin lesions are typically either hypopigmented or hyperpigmented macules or plaques. Patients may note that these lesions are anesthetic or paresthetic.
Causes
- M leprae is the causative agent associated with leprosy, which has been recognized as an infectious disease for the last 2 millennia. M leprae was discovered as the causative agent in 1873. The acid fast, gram-positive bacillus is an obligate intracellular organism with a predilection for Schwann cells and macrophages. M leprae has not been successfully grown using artificial media.
- The route of transmission has not been definitively established, although human-to-human aerosol spread of nasal secretions is thought to be the most likely mode of transmission in most cases. The disease is not spread by touch, since the mycobacteria are incapable of crossing intact skin. Living near people with leprosy is associated with increased transmission. Among household contacts, the relative risk for leprosy is increased 8- to 10-fold in multibacillary and 2- to 4-fold in paucibacillary forms. Animal reservoirs do exist (armadillos, certain nonhuman primates), and cases of suspected zoonotic transmission have been reported.
Other Problems to be Considered
Sensory loss (hypoesthesia) or neuropathy
Diabetic neuropathy
Sarcoidosis
Neuropathies due to medications (ie, stavudine, didanosine, acetazolamide, vincristine, gabapentin [Neurontin], isoniazid)
Vitamin B-12 or folate deficiency
Skin lesions - Flat and hypopigmented
Tinea corporis
Contact dermatitis
Seborrheic dermatitis
Localized scleroderma
Onchocerciasis
Pityriasis alba
Pityriasis versicolor
Post–kala azar dermal leishmaniasis
Vitiligo
Yaws
Skin lesions - Raised and pigmented
Syphilis
Atypical necrobiosis of the face
Cutaneous leishmaniasis
Follicular mucinosis
Granuloma annulare
Granuloma multiforme
Kaposi sarcoma
Lupus vulgaris
Lupus erythematosus
Mycobacterium marinum infection
Neurofibromatosis
Pityriasis rosea
Psoriasis
Wegener granulomatosis
Generalized thickening of skin
Myxoedema
Pachydermoperiostitis
Scleroderma
Lab Studies
- Skin biopsy, nasal smears, or both for acid-fast bacilli using Fite stain
- Laboratory tests related to drug treatment follow-up s include the following:
- Complete blood cell count
- Creatinine level
- Liver function tests
Other Tests
- Immunologic tests include the following:
- Lepromin skin test (not available in the United States): Although not diagnostic of exposure or infection with M leprae, this test assesses a patient's ability to mount a granulomatous response against a skin injection of killed M leprae. Patients with tuberculoid or borderline lepromatous leprosy typically have a positive response (>5 mm). Patients with lepromatous leprosy typically have no response.
- PGL-1: This is A specific serologic test based on the detection of antibodies to phenolic glycolipid-1 (PGL-1). This test has a sensitivity of 95% for the detection of lepromatous disease but only 30% for tuberculoid disease.
- Polymerase chain reaction (PCR): PCR and recombinant DNA technology have allowed for the development of gene probes with M leprae–specific sequences. This technology can be used to identify the mycobacterium in biopsy samples, skin and nasal smears, and blood and tissue sections.
- Lymphocyte migration inhibition test (LMIT): As determined by a lymphocyte transformation and LMIT, cell-mediated immunity to M leprae is absent in the lepromatous form of disease but present in the tuberculoid form of disease.
- Contact or family screening for history of leprosy
Procedures
- Skin biopsy samples stained with hematoxylin-eosin and Fite-Faraco are the primary basis for laboratory diagnosis and categorization. A full-thickness skin biopsy sample should be taken from an advancing border of an active lesion and should include dermis and epidermis. Skin smears that demonstrate acid-fast bacilli strongly suggest the diagnosis, but the bacilli may not be demonstrable in the tuberculoid (paucibacillary) form of the disease.
- A nerve biopsy can be beneficial in ruling out diseases such as hereditary neuropathies or polyarteritis nodosa. They may also help identify abnormalities in subclinical leprosy and may be the only way to diagnose definitively in people with completely neuropathic forms of leprosy.
Histologic Findings
Findings vary but can include dermatitis, giant cells, infiltration of nerve bundles with mononuclear cells, and granulomas Lepromatous lesions generally contain numerous acid-fast bacilli and fat-laden macrophages with a paucity of lymphocytes (see Image 8). In contrast, tuberculoid lesions contain few-to-no acid-fast bacilli but manifest granulomatous changes with epithelial cells and lymphocytes. The immunopathologic spectrum of leprosy has been delineated in the Leprosy topic in eMedicine's Neurology section.
Medical Care
In response to increased incidence of dapsone resistance, the WHO introduced a multidrug regimen in 1981 that includes rifampicin, dapsone, and clofazimine. Some clinical studies have also shown that certain quinolones, minocycline, and azithromycin have activity against M leprae. The WHO recently recommended single-dose treatment with rifampin, minocycline, and ofloxacin for paucibacillary cases with a single skin lesion. However, the WHO still recommends use of the long-term multidrug regimens whenever possible because they have been found to be more efficacious.
- The WHO recommends the following multidrug therapy plan:
| Type of Leprosy | Daily, Self-Administered | Monthly Supervised | Months of Treatment |
|---|
| Paucibacillary | Dapsone 100 mg | Rifampicin 600 mg | 6-12 | | Multibacillary | Dapsone 100 mg, Clofazimine 50 mg | Rifampicin 600 mg, Clofazimine 300 mg | 24 | | Pediatric | Dapsone 2 mg/kg, Clofazimine 1 mg/kg | Rifampicin 10 mg/kg, Clofazimine 6 mg/kg | Same as in adults |
- US regimens emphasize the use of rifampin, which is the most bactericidal drug used to treat leprosy. Although a single dose of 600 mg once monthly (the WHO standard) is considered bactericidal, treatment plans in the United States may include 600-mg/day doses.
- Patients with paucibacillary leprosy should receive dapsone 100 mg/day unsupervised plus rifampin 600 mg/day supervised for 6-12 months. This regimen should be followed by treatment with dapsone as monotherapy for 3 years for I and tuberculoid leprosy and 5 years for borderline lepromatous leprosy.
- Patients with multibacillary leprosy should receive (1) dapsone 100 mg/day plus clofazimine 50 mg/day unsupervised or (2) rifampin 600 mg/day plus clofazimine 300 mg every month supervised for 24 months.
Surgical Care
The goals of surgical treatment in leprosy are to prevent further deterioration, to improve motor function, and, in some cases, to improve sensation.
- Preoperative requirements: First, a full sensory and motor appraisal with functional and occupational assessment must be completed to determine the extent of damage. Additionally, patients must have completed the multidrug therapy and should have negative skin smear results. The patient should not use steroids a few months before surgery, and acute neuritis should not be evident. Stiffness of hands and feet should be minimized through preoperative therapy.
- Neural surgery
- Attempts to restore autonomic function and sensation are rarely undertaken since little evidence shows that function is significantly regained. Draining of acute nerve abscesses and fascicular dissection can reduce the pressure on nerves and may improve sensation. In some cases, longitudinal epineurotomy may relieve sensory loss to some extent. Considerable nerve function can be regained in the posterior tibial nerve with neurovascular decompression through release of the flexor retinaculum. Calcaneal bands can be slit to relieve distal compression of branches on the sole of the foot.
- Nerve grafts may be of some benefit in those with localized lesions. Neural surgery may also be indicated in cases of unremitting nerve pain.
- Reconstruction and functional restoration
- In leprosy management, most surgery aims to remedy motor paralysis due to primary nerve impairment. The claw finger and Z-thumb caused by ulnar nerve paralysis are some of the most common deformities. Claw hands are repaired with arthrodesis or with a tendon transfer to 1 of 4 insertion sites on the finger: interosseus tendons, proximal phalanx, dorsal extensor expansion, or flexor sheath annular pulleys. The palmaris longus, flexor digitorum superficialis, extensor carpi radialis longus, and extensor indices are tendons that can be used for transfer. Tendon transfers are also used to repair abduction and opposition of the thumb, dorsiflexion of the foot, and flexion and extension of the metacarpophalangeal and proximal interphalangeal joints, respectively.
- Contractures of the hand, such as the thumb web contracture, can be repaired with Z-plasty, and joint stability can be improved with tenodesis.
- The constrictions caused by repetitive injury and healing in leprosy can be treated with several methods. Possible treatment options include removal of the carpal tunnel roof, ulnar nerve transposition anteriorly, and epicondylectomy.
- Procedures that limit hyperextension of the metacarpophalangeal joint or keep it in flexion are not indicated in the insensate hands of patients with leprosy, which suffer from continued weakness.
- Amputation is a last resort and is reserved for cases of extremely diseased tissue.
- Eye procedures: Loss of eyelid function may be treated with passing a strip from the temporalis muscle through the eyelid and connecting it to the inner canthus. Tarsorrhaphy may help narrow the opening of the eyelid, and canthoplasty reduces sagging of the eyelids.
- Cosmetic surgery: After the disease is controlled medically, the following cosmetic procedures may also be considered:
- Nasal reconstruction
- Removal of excess skin
- Replacement of eyebrows using transplants of scalp hair
- Removal of breast tissue formation due to gynecomastia
Consultations
Consultations may include an orthopedic surgeon, dermatologist, neurologist, and physical therapist, based on the needs of the individual patient.
The goals of pharmacotherapy are to eradicate the infection, to prevent complications, and to reduce morbidity.
Drug Category: Antitubercular agents
These agents have bactericidal and bacteriostatic activity against mycobacteria.
| Drug Name | Dapsone (Avlosulfon) |
| Description | Bactericidal and bacteriostatic against mycobacteria; mechanism of action is similar to that of sulfonamides, in which competitive antagonists of PABA prevent formation of folic acid, inhibiting bacterial growth. Part of a 2-drug regimen for treatment of paucibacillary leprosy; part of a 3-drug regimen for treatment of multibacillary leprosy. |
| Adult Dose | Paucibacillary leprosy: 100 mg/d PO for 6-12 mo Multibacillary leprosy: 100 mg/d PO for 24 mo |
| Pediatric Dose | 1-2 mg/kg/d PO; not to exceed 100 mg/d |
| Contraindications | Documented hypersensitivity; known G-6-PD deficiency; porphyria; anemia |
| Interactions | May inhibit anti-inflammatory effects of clofazimine; hematologic reactions may increase with folic acid antagonists, eg, pyrimethamine (monitor for agranulocytosis during second and third mo of therapy); probenecid increases dapsone toxicity; trimethoprim with dapsone may increase toxicity of both drugs; because of increase in renal clearance, dapsone levels may significantly decrease when administered concurrently with rifampin |
| Pregnancy | C - Safety for use during pregnancy has not been established.
|
| Precautions | Obtain weekly blood counts (first mo), then obtain WBC counts monthly (6 mo), then semiannually; discontinue upon significant reduction in platelets, leukocytes, or hematopoiesis Caution in methemoglobin reductase deficiency, G-6-PD deficiency, or hemoglobin M because of the high risk of hemolysis and Heinz body formation; caution in patients exposed to other agents or conditions (eg, infection, diabetic ketosis) capable of producing hemolysis Peripheral neuropathy can occur (rare) Phototoxicity may occur when exposed to UV light |
| Drug Name | Rifampin (Rifadin, Rimactane) |
| Description | For use in combination with at least 1 other antituberculous drug; inhibits DNA-dependent bacterial but not mammalian RNA polymerase. Most bactericidal drug used against M leprae. Cross-resistance may occur. Treat for 6-9 mo or until 6 mo have elapsed from conversion to sputum-culture negativity. Part of 2-drug regimen for treatment of paucibacillary leprosy; part of 3-drug regimen for treatment of multibacillary leprosy. |
| Adult Dose | Paucibacillary leprosy: 600 mg/mo PO/IV for 6 mo Multibacillary leprosy: 600 mg/mo PO/IV for 24 mo |
| Pediatric Dose | 10-20 mg/kg PO/IV; not to exceed 600 mg/d |
| Contraindications | Documented hypersensitivity; reversal reactions or ENL; liver disease; jaundice; lactation |
| Interactions | Induces microsomal enzymes, which may decrease effects of acetaminophen, oral anticoagulants, barbiturates, benzodiazepines, beta-blockers, chloramphenicol, oral contraceptives, corticosteroids, mexiletine, cyclosporine, digitoxin, disopyramide, estrogens, hydantoins, methadone, clofibrate, quinidine, dapsone, tazobactam, sulfonylureas, theophyllines, tocainide, and digoxin; blood pressure may increase with coadministration of enalapril; coadministration with isoniazid may result in higher rate of hepatotoxicity than with either agent alone (discontinue one or both agents if alterations in LFTs occur) |
| Pregnancy | C - Safety for use during pregnancy has not been established.
|
| Precautions | Obtain CBC count and baseline clinical chemistries prior to and throughout therapy; in liver disease, weigh benefits against risk of further liver damage; interruption of therapy and high-dose intermittent therapy are associated with thrombocytopenia that is reversible if therapy is discontinued as soon as purpura occurs; if treatment is continued or resumed after appearance of purpura, cerebral hemorrhage or death may occur; may cause red-orange discoloration of urine, feces, saliva, sweat, sputum, and tears |
| Drug Name | Clofazimine (Lamprene) |
| Description | Inhibits mycobacterial growth, binds preferentially to mycobacterial DNA. Has antimicrobial properties, but mechanism of action is unknown. Part of 3-drug regimen for treatment of multibacillary leprosy. |
| Adult Dose | 50 mg/d PO for 24 mo in combination with dapsone and rifampin |
| Pediatric Dose | 1 mg/kg/d PO qd in combination with dapsone and rifampin (when self-administered) and 6 mg/kg/d PO if supervised |
| Contraindications | Documented hypersensitivity |
| Interactions | Dapsone may inhibit anti-inflammatory activity of clofazimine |
| Pregnancy | C - Safety for use during pregnancy has not been established.
|
| Precautions | Patients should be warned that clofazimine may discolor skin, body fluids, and excrement; color ranges from pink to brownish-black; severe abdominal symptoms may require exploratory laparotomies; caution in patients with GI problems (eg, abdominal pain, diarrhea); skin discoloration due to drug may result in depression or suicide; apply oil to skin for dryness and ichthyosis |
Further Outpatient Care
- The WHO recommends that the monthly doses of rifampin be administered under direct observation during the visit.
- Monthly outpatient follow-up is recommended during treatment, although weekly visits may be necessary if the patient experiences a leprosy reaction.
- Follow-up laboratory studies during treatment include the following:
- Urinalyses
- Blood count
- Creatinine
- Liver function tests
- Yearly skin scrapings taken from the 3 or 4 most active lesions are recommended.
- Response to treatment
- Successful treatment can result in flattening and elimination of nodules, papules, and plaques, as well as improved nerve function. Bacillary load is rarely a convenient method of assessing response to treatment. Noncompliance or drug resistance should be suspected if intact organisms are present after several months of treatment.
- Once treatment is completed, the patient should be monitored for the next 5-10 years to evaluate for signs of relapse. To date, the relapse rate with multidrug therapy has been 1% for both types of leprosy. In such cases, new bacillus-positive lesions may develop and should be treated with a thorough US regimen that incorporates once-daily rifampin (see Treatment).
- Patients who have been successfully treated occasionally develop reversal reactions and further neuropathy. If skin biopsy samples are bacillus-negative, these patients are deemed to have a reversal reaction as described below.
Complications
- Careful attention to the development of reversal reactions during treatment and prompt and proper management will minimize long-term neurologic sequelae.
- Type 1 reaction
- Reversal reaction, or lepra type 1 reaction, is a delayed-type hypersensitivity reaction that arises when a borderline case shifts toward borderline lepromatous with treatment. These types of reactions reflect the development of an appropriate immune response and the local generation of tumor necrosis factor-alpha and interferon-gamma. The reaction is characterized by edema and erythema of existing skin lesions, the formation of new skin lesions, neuritis, and additional sensory and motor loss.
- Treatment includes nonsteroidal anti-inflammatory drugs (NSAIDs) and high-dose steroids. Prednisone is given at a dose of 40-60 mg/day with a decreasing taper of 5 mg every 2-4 weeks.
- Type 2 reaction
- Erythema nodosum leprosum (ENL), also known as lepra type 2 reaction, is a complication of the lepromatous form of the disease. It is characterized by the development of inflamed subcutaneous nodules accompanied at times by fever, lymphadenopathy, and arthralgias. Treatment includes prednisolone, clofazimine, or thalidomide (see Images 9-10).
- Mild ENL reactions are treated with aspirin 600-1200 mg/day in 4-6 doses per day
- Severe ENL reactions are treated with prednisone 60-80 mg/day with a slow taper, reducing by 5-10 mg every 2-4 weeks, depending on response and severity, to prevent residual deformity and nerve damage.
- Alternatively, thalidomide 100 mg PO 4 times per day(if available and if no contraindications) can be used in cases that involve large subcutaneous plaques, arthritis, and temperature of more than 38.8°C.
- Lucio phenomenon is a severe complication of multibacillary leprosy that is marked by blue hemorrhagic plaques and necrotic ulcerations. The bacilli may extend to the endothelial cells along with the appearance of necrotic epidermis and vasculitis with thrombus formation and endothelial proliferation.
Prognosis
- Recovery from neurologic impairment is limited, but skin lesions generally clear within the first year of therapy. Discoloration and skin damage typically persist.
- Physical therapy, reconstructive surgery, nerve and tendon transplants, and surgical release of contractures all have contributed to increasing the functional ability of patients with leprosy. A common residual deformity is insensitive feet, as seen in persons with diabetes.
Patient Education
- Regional ambulatory clinics: The National Hansen's Disease Programs (NHDP) provide outpatient services and medical care to patients with leprosy in the United States and Puerto Rico. With the goals of prevention and early detection, the program supports delivery of services in areas with considerable populations of patients with leprosy. For additional information about these free services, contact the NHDP directly at 1-800-642-2477. The NHDP Center in Baton Rouge, La, provides free histopathologic services to facilitate diagnosis. Eleven outpatient HD clinics are located at hospitals, universities, and public health departments in Arizona, California, Florida, Illinois, Massachusetts, New York, Puerto Rico, Texas, and Washington. These clinics provide the following services:
- Skin biopsy diagnostic confirmation
- Additional medical care
- Hospitalization for treatment complications
- Consultations
- Materials for professional and patient education
- Patients should be advised about the importance of continuing long-term therapy until the course of antibiotics is completed. The WHO recommends that the monthly administration of rifampin be directly observed.
- In cases of leprosy with advanced nerve damage, self-care techniques are of utmost importance in maintaining function and preventing further disability. The use of visual input to regulate activity, self-inspection, hygiene, and proper footwear can help prevent ulcer formation and tissue damage.
- The WHO recommends examination of all household contacts, with careful instructions to seek medical care if signs and symptoms of leprosy appear.
- Pregnancy in patients with leprosy can result in hormonal changes that lead to suppression of cell-mediated immunity, which may exacerbate symptoms of leprosy. Furthermore, pregnant women with leprosy have a greater risk of developing reactions and relapses. Type I reactions are more often seen during the first few months after childbirth, whereas type II reactions typically occur during the third trimester of pregnancy and during lactation.
| Media file 1:
Hands with Z-thumbs, clawing, contractures, and shortening of fingers due to repetitive injury and healing. Ho Chi Minh City, Vietnam. (Courtesy of D. Scott Smith, MD) |
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Patient with facial nerve palsy and contractures of the hand. Daloa, Ivory Coast. (Courtesy of D. Scott Smith, MD) |
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Chronic insensate patch due to leprosy infection. Ho Chi Minh City, Vietnam. (Courtesy of D. Scott Smith, MD) |
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Characteristic clawed hand deformity caused by ulnar involvement in leprosy. Daloa, Ivory Coast. (Courtesy of D. Scott Smith, MD) |
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Chronic nonhealing ulcer at the metatarsal head resulting from loss of sensation in the feet. Karigiri, Tamil Nadu, India. (Courtesy of Tara Ramachandra) |
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Multiple flat hypopigmented lesions on shoulder and neck, suggestive of multibacillary leprosy. Note ulceration of hypothenar area of hand, indicative of ulnar neuropathy. Redwood City, California, United States. (Courtesy of D. Scott Smith, MD) |
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Man with advanced deformities caused by unmanaged leprosy. Keratitis, loss of eyebrow, thickened skin, and typical hand impairments. Ho Chi Minh City, Vietnam. (Courtesy of D. Scott Smith, MD) |
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Histopathology of leprosy: Large numbers of acid-fast bacilli (in clusters) in histiocytes and within nerves. Fite-Faraco stain 500 X. (Courtesy of Tara Ramachandra and D. Scott Smith, MD) |
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Patient with multibacillary leprosy showing subsequent erythema nodosum leprosum reaction. Santa Clara, California. (Courtesy of D. Scott Smith, MD) |
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Patient with erythema nodosum leprosum type 2 leprae reaction several weeks after initiation of drug therapy. This photograph was taken after tendon release. Redwood City, California. (Courtesy of D. Scott Smith, MD) |
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Leprosy excerpt Article Last Updated: Jul 24, 2006
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