Leprosy in Children - A Complete Guide

Introduction

Hansen’s disease, popularly known as leprosy, is a contagious disease that occurs due to the bacterial antigen Mycobacterium leprae. The major problem with this kind of infectious disease is the spread of infection throughout society. Hence, it always remains a concern to maintain public health when there is an outbreak of leprosy. Leprosy is also thought of as an infectious disease that attacks adults. However, the incidence of Mycobacterium leprae infection among kids also remains high, with the most common age group being 10 to 14 years.

What Is Childhood Leprosy?

Infection due to Mycobacterium leprae, which thrives in and around tropical regions, can cause serious clinical manifestations in children and is known as childhood leprosy. This infectious agent is known to infect at least 10 to 15 percent of young kids globally.

Etiopathogenesis:

• Mycobacterium leprae reaches the kids through droplets from people who are infected around them. This means that close contact with infectious people can make the child contract leprosy infection very easily. This happens to children in endemic areas who remain in contact with people who have undiagnosed leprosy. Since kids have an underdeveloped immune system, the probability of getting a leprosy infection easily is very high.

• When the bacterium reaches the child’s body, it has a greater affinity for regions of low or cool temperature. Since skin and nerves have low temperatures, they are the most commonly involved sites in leprosy infection.

• The clinical manifestations of leprosy largely depend on how well the child’s immune system combats this bacterial antigen. If the child’s cell-mediated immunity is good, a milder version of the disease only manifests, and in such cases, the bacterial load in the body is also very minimal. However, in children with weak immunological defenses or excessive humoral immunity, the body may not be able to control the bacterial load, which can lead to widespread dermatological and neurological involvement.

• In advanced cases, the bacterium can escape all kinds of defense mechanisms and infect Schwann cells of the nerve.

What Are the Clinical Manifestations of Childhood Leprosy?

Clinical Features Noted in Children:

Varied clinical manifestations affecting the skin and nerve can be noted based on how well the immunological system of the affected kids functions.

Skin Manifestations:

• The first sign a parent or a caregiver can notice in a child is the presence of such hypopigmented areas.

• The skin may exhibit a hypopigmented (discolored) patch or macular or papular growth. In advanced cases, even nodules caused by the bacterium are noted. Such areas appear red. In rare cases, the region may ulcerate completely.

• If left untreated, the leprae bacteria can infiltrate deep into the layers of the skin and cause thick plaque formation. When such infiltration and plaque formation occurs in the face, the child may exhibit a “leonine facies” appearance.

• Eyebrows and eyelashes will be lost, which can cause significant facial disfigurement.

Nerve Manifestations:

• The first step the bacteria takes is infiltrating peripheral nerves in the body and subsequent thickening. Once a nerve thickens, the areas supplied by the nerve can become extremely painful and weak.

• This later causes loss of sensation. Thus, localized loss of sensation, along with the presence of skin lesions, is one of the first clinical features noted in children.

• Once the bacteria multiplies in the body, it can start to invade the motor nerves as well. This can result in extreme weakness of the muscles and resultant paralysis.

• Children in such cases begin to have claw hand deformity and foot drop (as the motor nerve supply to hands and feet is highly compromised).

• In advanced cases, autonomic nerves can become involved, causing the child to have persistent dry and cracked skin.

Other Manifestations:

• Inability to close eyelids.

• Ulcers within the cornea.

• Inflammation of the iris and surrounding structures.

• Fever.

• Lymph node enlargement.

• Malaise.

• Generalized fatigue.

• Lepra reactions (acute exacerbation of chronic lepromatous lesions).

• Delayed growth in children.

Types of Leprosy Seen in Children:

Based on the varied manifestations and severity of this infection, leprosy in children is of two types.

• Paucibacillary Type - In this leprosy, the bacterial load is minimal, and skin involvement is limited to superficial hypopigmented patches. Nerve involvement is limited to lack of sensation and localized weakness only. Among children, the paucibacillary type is the most commonly observed.

• Multibacillary Type - This is a severe version, and there is extensive cutaneous and nervous system involvement.

How to Diagnose Leprosy in Children?

The road to diagnosing leprosy in children can be very challenging as they present with bizarre or atypical symptoms and one can easily misinterpret such lesions as eczema or vitiligo. This is also accompanied by a lack of knowledge about the signs in endemic areas, where the disease is most prevalent. The following ways can be used in diagnosing leprosy in kids.

• A close look into the skin lesions along with neurological manifestations should be correlated through physical general examination.

• A smear can be obtained from the skin lesions by a test called slit-skin-smear. Once the dermatological sample is obtained, the Ziehl-Neelsen technique of acid-fast bacilli staining will be performed. The lepra bacteria appear as red rod-like structures against a bluish background.

• Skin biopsy can also be performed.

• A test commonly used to evaluate the immune response in affected children is the lepromin test. In this test, inactivated bacteria are injected into the child through an intradermal route. If new skin lesions form around the injection site, the test is said to be positive and confirms the presence of a tuberculoid type of leprosy.

• Nerve involvement will be checked thoroughly through nerve conduction tests.

• Hematological tests that can confirm the presence of M.leprae include anti-PGL-1 antibodies test and polymerase chain reaction.

How to Manage Childhood Leprosy?

The type of leprosy decides the type of management strategy.

Medications:

• Children with paucibacillary leprosy will receive Dapsone and Rifampicin for six months.

• For multibacillary leprosy, an additional drug, Clofazimine, will be added, and the total duration for all three drugs will be 12 months.

Auxiliary Support:

• Physiotherapy for weakened muscles.

• Skin moisturizers to prevent scaling.

• Frequent ocular examination to identify eye manifestations early.

• Psychological support (for kids and caregivers).

Available Vaccine and Associated Data:

The Bacillus Calmette-Guerin (BCG) vaccine is mainly given for immunity against tuberculosis. It can also have some protective effects against leprosy, particularly in children. However, this portion has not yet been studied extensively to give a clear picture of the role of the BCG vaccine against leprosy.

Conclusion

Leprosy is a very preventable disease if people who are in contact with kids are aware of the condition. Children should also be made aware of the clinical signs of leprosy and should be taught to avoid contact with people who are infected around them, specifically in endemic areas. Education should empower such children with adequate knowledge about infectious diseases so that prevention and cure become possible from a very nascent stage.