What is leprosy?

What is the history of leprosy (Hansen's disease)?

What causes leprosy?

What are the symptoms and signs of leprosy?

Are there different forms (classifications) of leprosy?

How is leprosy transmitted?

How is leprosy diagnosed?

How is leprosy treated?

How is leprosy prevented?

Where can I find more information on leprosy?

Leprosy (Hansen's Disease) At A Glance

What is leprosy?

Leprosy is a disease caused by the bacteria Mycobacterium leprae that causes damage

to the skin and the peripheral nervous system. The disease develops slowly (from six

months to 40 years!) and results in skin lesions and deformities, most often affecting the

cooler places on the body (for example, eyes, nose, earlobes, hands, feet, and

testicles). The skin lesions and deformities can be very disfiguring and are the reason

that infected individuals were considered outcasts in many cultures. Although human-to-

human transmission is the primary source of infection, three other species can carry

and (rarely) transfer M. leprae to humans; chimpanzees, mangabey monkeys, and nine-

banded armadillos. The disease is termed a chronic granulomatous disease because it

produces inflammatory nodules (granulomas) in the skin and nerves over time.

Picture of a person with leprosy (Hansen's disease)

What is the history of leprosy (Hansen's disease)?

Unfortunately, the history of leprosy and its interaction with man is one of suffering and

misunderstanding. The newest research suggests that at least as early as 4000 B.C.

individuals had been infected with M. leprae (studies are ongoing to prove this by

genetic analysis), while the first known written reference to the disease was found on

Egyptian papyrus in about 1550 B.C. The disease was well recognized in ancient China,

Egypt, and India. Because the disease was poorly understood, very disfiguring, slow to

show symptoms, and had no known treatment, many cultures thought the disease was

a curse or punishment from the gods. Consequently, leprosy was left to be "treated" by

priests or holy men, not physicians.

Since the disease often appeared in family members, some people thought it was

hereditary; other people noted that if there was little or no contact with infected

individuals, the disease did not infect others. Consequently, some cultures considered

infected people (and occasionally their close relatives) as "unclean" or as " lepers" and

ruled they could not associate with uninfected people. Often infected people had to

wear special clothing and ring bells so uninfected people could avoid them.

The Romans and the Crusaders brought the disease to Europe, and the Europeans

brought it to the Americas. In 1873, Dr. Hansen discovered bacteria in

leprosy lesions, suggesting leprosy was an infectious disease, not hereditary or a

punishment from the gods. However, patients with the disease were still ostracized by

many societies and cared for only at missions by religious personnel. Patients with

leprosy were encouraged or forced to live in seclusion up to the 1940s, even in the U.S.

(for example, the leper colony on Molokai, Hawaii, and at Carville, La.), often because

no effective treatments were available. Because of Hansen's discovery of M. leprae,

efforts were made to find treatments that would stop or eliminate M. leprae; in the early

1900s to about 1940, oil from Chaulmoogra nuts was used with questionable efficacy by

injecting it into patients' skin. At Carville in 1941, Promin, a sulfone drug, showed

efficacy but needed many painful injections. Dapsone pills were found to be effective in

the 1950s, but soon (1960s-70s), M. leprae developed resistance to dapsone.

Fortunately, drug trials on the island of Malta in the 1970s showed that a three-drug

combination (dapsone, rifampicin, and clofazimine [Lamprene]) was very effective in

killing M. leprae. This multi-drug treatment (MDT) was recommended by the WHO in

1981 and remains, with minor changes, the therapy of choice. MDT, however, does not

alter the damage done to an individual by M. leprae before MDT is started.

Leprosy is often termed "Hansen's disease" by many clinicians in an attempt to have

patients forgo the stigmas attached to being diagnosed with leprosy.

What causes leprosy?

Leprosy is caused by Mycobacterium leprae, a rod-shaped bacillus that is an obligate

intracellular (only grows inside of certain human and animal cells) bacterium. M.

leprae is termed an "acid fast" bacterium because of its chemical characteristics. When

special stains are used for microscopic analysis, it stains red on a blue background due

to mycolic acid content in its cell walls. The Ziel-Nielsen stain is an example of the

special staining techniques used to view the acid-fast organisms under the microscope.

Currently, the organisms cannot be cultured on artificial media. The bacteria take an

extremely long time to reproduce inside of cells (about 12-14 days as compared to

minutes to hours for most bacteria). The bacteria grow best at 80.9 F-86 F, so cooler

areas of the body tend to develop the infection. The bacteria grow very well in the

body's macrophages and Schwann cells (cells that cover and protect nerve axons). M.

leprae is genetically related to M.tuberculosis (the type of bacteria that cause

tuberculosis) and other mycobacteria that infect humans. As with malaria, patients with

leprosy produce anti-endothelial antibodies (antibodies against the lining tissues of

blood vessels), but the role of these antibodies in these diseases is still under

investigation.

What are the symptoms and signs of leprosy?

Unfortunately, the early signs and symptoms of leprosy are very subtle and occur slowly

(usually over years). Numbness and loss of temperature sensation (cannot sense very

hot or cold temperatures) are some of the first symptoms that patients experience. As

the disease progresses, the sensation of touch, then pain, and eventually deep

pressure are decreased or lost. Signs that occur, such as relatively painless ulcers, skin

lesions of hypopigmented macules (flat, pale areas of skin), and eye damage (dryness,

reduced blinking) are experienced before the large ulcerations, loss of digits, and facial

disfigurement develop. This long-time developing sequence of events begins and

continues on the cooler areas of the body (for example, hands, feet, face, and knees).

Are there different forms (classifications) of leprosy?

There are multiple forms of leprosy described in the literature. The forms of leprosy are

based on the person's immune response to M. leprae. A good immune response can

produce the so-called tuberculoid form of the disease, with limited skin lesions and

some asymmetric nerve involvement. A poor immune response can result in the

lepromatous form, characterized by extensive skin and symmetric nerve involvement.

Some patients may have aspects of both forms. Currently, two classification systems

exist in the medical literature: the WHO system and the Ridley-Jopling system. The

Ridley-Jopling system is composed of six forms or classifications, listed below

according to increasing severity of symptoms:

Indeterminate leprosy: a few hypopigmented macules; can heal spontaneously,

persists or advances to other forms

Tuberculoid leprosy: a few hypopigmented macules, some are large and some

become anesthetic (lose pain sensation); some neural involvement in which nerves

become enlarged; spontaneous resolution in a few years, persists or advances to

other forms

Borderline tuberculoid leprosy: lesions like tuberculoid leprosy but smaller and more

numerous with less nerve enlargement; this form may persist, revert to tuberculoid

leprosy, or advance to other forms

Mid-borderline leprosy: many reddish plaques that are asymmetrically distributed,

moderately anesthetic, with regional adenopathy (swollen lymph nodes); the form

may persist, regress to another form, or progress

Borderline lepromatous leprosy: many skin lesions with macules (flat lesions)

papules (raised bumps), plaques, and nodules, sometimes with or without

anesthesia; the form may persist, regress or progress to lepromatous leprosy

Lepromatous leprosy: Early lesions are pale macules (flat areas) that are diffuse and

symmetric; later many M. leprae organisms can be found in them. Alopecia(hair

loss) occurs; often patients have no eyebrows or eyelashes; as the disease

progresses, nerve involvement leads to anesthetic areas and limb weakness;

progression leads to aseptic necrosis (tissue death from lack of blood to area),

lepromas (skin nodules), and disfigurement of many areas including the face; the

lepromatous form does not regress to the other less severe forms.

The Ridley-Jopling classification is used globally in evaluating patients in clinical

studies. However, the WHO classification system is more widely used; it has only two

forms or classifications of leprosy. The 2009 WHO classifications are simply based on

the number of skin lesions as follows:

Paucibacillary leprosy: skin lesions with no bacilli (M. leprae) seen in a skin smear

Multibacillary leprosy: skin lesions with bacilli (M. leprae) seen in a skin smear

However, the WHO further modifies these two classifications with clinical criteria

because "�of the non-availability or non-dependability of the skin-smear services. The

clinical system of classification for the purpose of treatment includes the use of number

of skin lesions and nerves involved as the basis for grouping leprosy patients into

multibacillary (MB) and paucibacillary (PB) leprosy." Investigators state that up to about

four to five skin lesions constitutes paucibacillary leprosy, while about five or more

constitutes multibacillary leprosy.

Mulitdrug therapy (MDT) with three antibiotics (dapsone, rifampicin, and clofazimine) is

used for multibacillary leprosy, while a modified MDT with two antibiotics (dapsone and

rifampicin) is recommended for paucibacillary leprosy. Paucibacillary leprosy usually

includes indeterminate, tuberculoid, and borderline tuberculoid leprosy from the Ridley-

Jopling classification, while multibacillary leprosy usually includes the double (mid-)

borderline, borderline lepromatous, and lepromatous leprosy.

How is leprosy transmitted?

Researchers suggest that M. leprae are spread person to person by nasal secretions or

droplets. They speculate that infected droplets reach other peoples' nasal passages and

begin the infection there. Some investigators suggest the infected droplets can infect

others by entering breaks in the skin. M. leprae apparently cannot infect intact skin.

Rarely, humans get leprosy from the few animal species mentioned above. Routes of

transmission are still being researched for leprosy.

How is leprosy diagnosed?

The majority of cases of leprosy are diagnosed by clinical findings, especially since

most current cases are diagnosed in areas that have limited or no laboratory equipment

available. Hypopigmented patches of skin or reddish skin patches with loss of

sensation, thickened peripheral nerves, or both clinical findings together often comprise

the clinical diagnosis. Skin smears or biopsy material that show acid-fast bacilli with the

Ziel-Nelson stain or the Fite stain (biopsy) can diagnose multibacillary leprosy, or if

bacteria are absent, diagnose paucibacillary leprosy. Other tests can be done, but most

of these are done by specialized labs and may help a clinician to place the patient in the

more detailed Ridley-Jopling classification and are not routinely done (lepromin test,

phenolic glycolipid-1 test, PCR, lymphocyte migration inhibition test or LMIT). Other

tests such as CBC test, liver function tests, creatinine test, or a nerve biopsy may be

done to help determine if other organ systems have been affected.

How is leprosy treated?

The majority of cases (mainly clinically diagnosed) are treated with antibiotics. The

recommended antibiotics, their dosages and length of time of administration are based

on the form or classification of the disease and whether or not the patient is supervised

by a medical professional. In general, paucibacillary leprosy is treated with two

antibiotics, dapsone and rifampicin, while multibacillary leprosy is treated with the same

two plus a third antibiotic, clofazimine. Usually, the antibiotics are given for at least six to

12 months or more. Each patient, depending on the above criteria, has a schedule for

their individual treatment, so treatment schedules should be planned by a clinician

knowledgeable about that patient's initial diagnostic classification.

Antibiotics can treat paucibacillary leprosy with little or no residual effects on the patient.

Multibacillary leprosy can be kept from advancing, and living M. leprae can be

essentially eliminated from the person by antibiotics, but the damage done before

antibiotics are administered is usually not reversible. Recently, the WHO suggested that

single-dose treatment of patients with only one skin lesion with

rifampicin, minocycline (Minocin), orofloxacin (Floxin) is effective. Studies of other

antibiotics are ongoing.

The role for surgery in the treatment of leprosy occurs after medical treatment

(antibiotics) has been completed with negative skin smears (no detectable acid-fast

bacilli) and is often only needed in advanced cases. Surgery is individualized for each

patient with the goal to attempt cosmetic improvements and, if possible, to restore limb

function and some neural functions that were lost to the disease.

How is leprosy prevented?

Prevention of contact with droplets from nasal and other secretions from patients with

untreated M. leprae infection currently is a way to avoid the disease. Treatment of

patients with appropriate antibiotics stops the person from spreading the disease.

People that live with individuals that have untreated leprosy are about eight times as

likely to develop the disease, because investigators speculate that family members

have close proximity to infectious droplets. Leprosy is not hereditary.

Many people get exposed to leprosy throughout the world, but the disease in not highly

contagious; researchers suggest that over 95% of exposures result in no disease. In the

U.S., there are about 200-300 new cases diagnosed per year, with most coming from

exposures during foreign travel. The majority of worldwide cases are found in the tropics

or subtropics (for example, Brazil, India, and Indonesia). The WHO reports about

500,000 to 700,000 new cases per year worldwide, with curing of about 14 million cases

since 1985.

There is no vaccine available to prevent leprosy. Animals (chimpanzees, mangabey

monkeys, and nine-banded armadillos) rarely transfer M. leprae to humans;

nonetheless, handling such animals in the wild is not advised.

Where can I find more information on leprosy?

http://www.cdc.gov/nczved/dfbmd/disease_listing/leprosy_ti.html

http://www.who.int/lep/classification/en/index.html

http://www.who.int/lep/mdt/en/

http://emedicine.medscape.com/article/1104977-overview

http://www3.niaid.nih.gov/topics/leprosy/Understanding/today.htm

Leprosy (Hansen's Disease) At A Glance

Leprosy is a slowly developing, progressive disease that damages the skin and

nervous system.

Leprosy is caused by an infection with Mycobacterium leprae bacteria.

Early symptoms begin in cooler areas of the body and include loss of sensation.

Signs of leprosy are painless ulcers, skin lesions of hypopigmented macules (flat,

pale areas of skin) and eye damage (dryness, reduced blinking). Later, large

ulcerations, loss of digits, skin nodules, and facial disfigurement may develop.

The infection is spread person to person by nasal secretions or droplets.

Antibiotics are used in the treatment of leprosy.

Leprosy Index

Featured: Leprosy Main ArticleLeprosy (Hansen's disease) is a disfiguring disease caused by infection with Mycobacterium leprae bacteria. The disease is spread from person to person through nasal secretions or droplets. Symptoms and signs of leprosy include numbness, loss of temperature sensation, painless ulcers, eye damage, loss of digits, and facial disfigurement. Leprosy is treated with antibiotics and the dosage and length of time of administration depends upon which form of leprosy the patient has.Medications

ofloxacin, Floxin dapsone - oral clofazimine-oral, Lamprene minocycline - injection, Minocin

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Glossary

Leprosy Glossary

Terms related to Leprosy:

Hansen's Disease

Leprosy

Leprosy is an infectious disease that has been known since biblical times. It is characterized by disfiguring skin sores, nerve damage, and progressive debilitation.

Causes

Leprosy is caused by the organism Mycobacterium leprae. It is not very contagious (difficult to transmit) and has a long incubation period (time before symptoms appear), which makes it difficult to determine where or when the disease was contracted. Children are more susceptible than adults to contracting the disease.

Leprosy has two common forms, tuberculoid and lepromatous, and these have been further subdivided. Both forms produce sores on the skin, but the lepromatous form is most severe, producing large, disfiguring lumps and bumps ( nodules).

All forms of the disease eventually cause nerve damage in the arms and legs, which causes sensory loss in the skin and muscle weakness. People with long-term leprosy may lose the use of their hands or feet due to repeated injury resulting from lack of sensation.

Leprosy is common in many countries worldwide, and in temperate, tropical, and subtropical climates. Approximately 100 cases per year are diagnosed in the United States. Most cases are limited to the South, California, Hawaii, and U.S. island possessions.

Effective medications exist, and isolation of victims in "leper colonies" is unnecessary. The emergence of drug-resistant Mycobacterium leprae , as well as increased numbers of cases worldwide, has led to global concern about this disease.

Symptoms

Symptoms include:

Skin lesions  that are lighter than your normal skin coloro Lesions have decreased sensation to touch, heat, or paino Lesions do not heal after several weeks to months

Numbness  or absent sensation in the hands, arms, feet, and legs Muscle weakness

Exams and Tests

Lepromin skin test  can be used to distinguish lepromatous from tuberculoid leprosy, but is not used for diagnosis

Skin lesion biopsy Skin scraping  examination for acid fast bacteria

Treatment

A number of different antibiotics are used to kill the bacteria that cause the disease.

Aspirin, prednisone, or thalidomide are used to control inflammation.

Outlook (Prognosis)

Early recognition is important. Early treatment limits damage by the disease, renders the person noninfectious (you can't catch the disease from them), and allows for a normal lifestyle.

Possible Complications

Cosmetic disfigurement Permanent nerve damage

When to Contact a Medical Professional

Call your health care provider if you have symptoms of leprosy, especially if you've had contact with someone who has the disease. Cases of leprosy in the United States need to be reported to the Centers for Disease Control and Prevention.

Prevention

Prevention consists of avoiding close physical contact with untreated people. People on long-term medication become noninfectious (they do not transmit the organism that causes the disease).

Alternative Names

Hansen's disease

Leprosy

Leprosy (Hansen's disease) is a chronic infection caused by the bacteria Mycobacterium leprae. It results in damage primarily to the peripheral nerves (the nerves outside the brain and spinal cord), skin, testes, eyes, and mucous membrane of the nose.

Leprosy ranges from mild (with one or a few skin areas affected) to severe (with many skin areas affected and damage to many organs).

Rashes and bumps appear, the affected areas become numb, and muscles may become weak.

The diagnosis is suggested by symptoms and confirmed by a biopsy of the affected tissue.

Antibiotics can stop leprosy from progressing but cannot reverse any nerve damage or deformity.

Because without treatment, people with leprosy are visibly disfigured and

often have significant disability, they have long been feared and shunned

by others. Although leprosy is not highly contagious, rarely causes death,

and can be effectively treated with antibiotics, it still causes anxiety. As a

result, people with leprosy and their family members often suffer

psychologic and social problems.

During 2007, over 250,000 new cases were reported. About 90% of these

cases occurred in the following eight countries (from the most cases to

the least): India, Brazil, Indonesia, Congo, Bangladesh, Nigeria, Nepal,

and Ethiopia. In 2006, 137 new cases were reported in the United States.

Cases occurred in 30 states, but over half occurred in six states:

California, Florida, Louisiana, Massachusetts, New York, and Texas.

Almost all cases of leprosy in the United States involve people who

emigrated from developing countries.

Leprosy can develop at any age but appears to develop most often in

people aged 5 to 15 years or over 30.

How leprosy is spread is unclear. However, it may be passed from

person to person through droplets expelled from the nose and mouth of

an infected person and breathed in or touched by an uninfected person.

But even after contact with the bacteria, most people do not contract

leprosy. About half of the people with leprosy probably contracted it

through close, long-term contact with an infected person. Casual and

short-term contact does not seem to spread the disease. Leprosy cannot

be contracted by simply touching someone with the disease, as is

commonly believed. Health care workers often work for many years with

people who have leprosy without contracting the disease. Armadillos are

the only confirmed source other than people, although other animal and

environmental sources may exist.

About 95% of people who are infected with Mycobacterium leprae do not

develop leprosy because their immune system fights off the infection.

People who develop leprosy may have genes that make them susceptible

to the infection once they are exposed.

Classification: Leprosy can be categorized by the type and number of

skin areas affected. Those with 5 or fewer affected skin areas have

leprosy that is called paucibacillary. People should have no bacteria

detectable on samples from those areas. Those with 6 or more affected

areas have leprosy that is called multibacillary. People may or may not

have bacteria detected on samples from those areas.

Leprosy can also be classified as tuberculoid, lepromatous, or borderline

according to the symptoms people have and other findings. People with

tuberculoid leprosy typically have few skin areas affected (paucibacillary),

and the disease is milder, less common, and less contagious. People

with lepromatous and borderline typically have more skin areas affected

(multibacillary), and the disease is more severe, common, and

contagious.

In both classifications, the type of leprosy dictates the long-term

prognosis, likely complications, and how long antibiotic treatment is

needed.

Tuberculoid Leprosy

Symptoms

Because the bacteria that cause leprosy multiply very slowly, symptoms

usually do not begin until at least 1 year after people have been infected.

On average, symptoms appear 5 to 7 years after infection. Once

symptoms begin, they progress slowly.

Leprosy affects mainly the skin and peripheral nerves Characteristic

rashes and bumps develop. Infection of the nerves makes the skin numb

or the muscles weak in areas controlled by the infected nerves.

Tuberculoid leprosy: A rash appears, consisting of one or a few flat, whitish areas. Areas affected by this rash are numb because the bacteria damage the underlying nerves.

Lepromatous leprosy: Many small bumps or larger raised rashes of variable size and shape appear on the skin. There are more areas of numbness than in tuberculoid leprosy, and certain muscle groups may be weak. Much of the skin and many areas of the body, including the kidneys, nose, and testes, may be affected.

Borderline leprosy: Features of both tuberculoid and lepromatous leprosy are present. Without treatment, borderline leprosy may become less severe and more like the tuberculoid form, or it may worsen and become more like the lepromatous form.

The most severe symptoms result from infection of the peripheral nerves,

which causes deterioration of the sense of touch and a corresponding

inability to feel pain and temperature. People with peripheral nerve

damage may unknowingly burn, cut, or otherwise harm themselves.

Repeated damage may eventually lead to loss of fingers and toes. Also,

damage to peripheral nerves may cause muscle weakness that can result

in deformities. For example, the fingers may be weakened, causing them

to curve inward (like a claw). Muscles may become too weak to flex the

foot—a condition called footdrop. Infected nerves may enlarge so that

during a physical examination, doctors can feel them.

Skin infection can lead to areas of swelling and lumps, which can be

particularly disfiguring on the face.

Other areas of the body may be affected:

Feet: Sores may also develop on the soles of the feet, making walking painful.

Nose: Damage to the nasal passages can result in a chronically stuffy nose and nosebleeds and, if untreated, complete erosion of the nose.

Eyes: Damage to the eyes may lead to glaucoma or blindness.

Sexual function: Men with lepromatous leprosy may have erectile dysfunction (impotence) and become infertile. The infection can reduce the amount of testosterone

and sperm produced by the testes.

Kidneys: The kidneys may malfunction. In severe cases, kidney failure may occur.

During the course of untreated or even treated leprosy, the immune

system may produce inflammatory reactions. These reactions can cause

fever and inflammation of the skin, peripheral nerves, and, less

commonly, the lymph nodes, joints, testes, kidneys, liver, and eyes. The

skin around bumps may swell and become red and painful, and the

bumps may form open sores. People may have a fever and swollen

lymph glands.

Diagnosis

Symptoms (such as distinctive rashes that do not disappear, enlarged

nerves, loss of the sense of touch, and deformities that result from

muscle weakness) provide strong clues to the diagnosis of leprosy.

Examination of a sample of infected skin tissue under a microscope

(biopsy) confirms the diagnosis. Because leprosy bacteria do not grow in

the laboratory, culture of tissue samples is not useful. Blood tests to

measure antibodies to the bacteria have limited usefulness because

antibodies are not always present.

Did You Know...

Leprosy is not easily spread.

If leprosy is severe, people may have to take antibiotics for the rest of their life.

Prevention

Because leprosy is not very contagious, risk of spread is low. Only the

untreated lepromatous form is contagious, although even then the

infection is not easily spread. Once treatment has begun, leprosy cannot

be spread. Avoiding contact with bodily fluids from and the rash on

infected people is the best prevention. The BCG (bacille Calmette-

Guérin) vaccine, used to prevent tuberculosis, provides some protection

against leprosy, but it is not often used to prevent leprosy.

Treatment

Antibiotics can stop the progression of leprosy but do not reverse any

nerve damage or deformity. Thus, early detection and treatment are

vitally important. Because some leprosy bacteria are resistant to certain

antibiotics, doctors prescribe more than one drug. The drugs chosen

depend on the type of leprosy:

Multibacillary: The standard combination of drugs is dapsone 

, rifampin 

, andclofazimine 

. People take rifampin 

and clofazimine 

once a month under a health care practitioner's supervision. They take dapsone 

plus clofazimine 

once a day on their own. This regimen is continued for 12 to 24 months, depending on the severity of the disease.

Paucibacillary: People take rifampin 

once a month with supervision and dapsone 

once a day without supervision for 6 months. People who have only a single affected skin area are given a single dose of rifampin 

, ofloxacin 

, and minocycline 

.

Dapsone 

is relatively inexpensive and generally safe to use. It occasionally causes

allergic rashes and anemia. Rifampin 

, which is more expensive, is even more effective than dapsone 

. Its most serious side effects are damage to the liver and flu-like

symptoms. Clofazimine 

is extremely safe. The main side effect is temporary skin pigmentation.

Because the bacteria are difficult to eradicate, antibiotics must be

continued for a long time. Depending on the severity of the infection and

the doctor's judgment, treatment continues from 6 months to many years.

Some doctors recommend lifelong treatment withdapsone 

for people with lepromatous leprosy

Mortality/Morbidity

If severe and left untreated, leprosy can cause clinically significant and debilitating deformity. Since 1943, when sulfone was introduced as the first effective treatment for leprosy, antibiotic treatment has dramatically improved patients' outcomes. Early diagnosis and effective antimicrobial treatment can arrest and even cure leprosy.

Race

Leprosy occurs in persons of all races. African blacks have a high incidence of the tuberculoid form of leprosy. People with light skin and Chinese individuals tend to contract the lepromatous type of leprosy. Leprosy is endemic in Asia, Africa, the Pacific basin, and Latin America (excluding Chile). Leprosy is more a rural than urban disease.

Sex

In adults, the lepromatous type of leprosy is more common in men than in women after puberty, with a male-to-female ratio of 2:1. In children, the tuberculoid form of leprosy predominates and no sex preference is reported. Women tend to have a delayed presentation, which increases rates of deformity.

Age

Leprosy has a bimodal age distribution, with peaks at ages 10-14 years and 35-44 years. Leprosy is rare in infants. Children appear to be most susceptible to leprosy and tend to have the tuberculoid form.

Leprosy (Hansen's disease)

Last Reviewed: November 2006

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Versión en español

What is leprosy?

Leprosy is a chronic bacterial disease of the skin and nerves in the hands and feet and, in some cases, the lining of the nose. Leprosy is a rare disease in the United States.

Who gets leprosy?

Anyone can get leprosy, but children seem to be more susceptible than adults.

How is leprosy spread?

It is not clear how the leprosy germ is spread, but household and prolonged close contact is important. The germs probably enter the body through the nose and possibly through broken skin. The germs get in the air through nasal discharge of untreated lepromatous patients.

What are the symptoms of leprosy?

Tuberculoid leprosy symptoms are a few well-defined skin lesions that are numb. Lepromatous leprosy symptoms are a chronically stuffy nose and many skin lesions and nodules on both sides of the body.

How soon after exposure do symptoms appear?

It usually takes about four years for tuberculoid leprosy symptoms to appear and about eight years for lepromatous leprosy symptoms to appear.

When and for how long is a person able to spread leprosy?

In most cases, a person will not infect others after about three months of starting treatment.

What is the treatment for leprosy?

Patients with leprosy should be treated by a doctor who has experience with the disease. Treatment is with multiple drugs for six months to two years.

How can leprosy be prevented?

The best way to prevent the spread of leprosy is the early diagnosis and treatment of people who are infected. For household contacts, immediate and annual examinations are recommended for at least five years after last contact with a person who is infectious.