Leprosy (Hansen's Disease)

• Leprosy is a chronic infectious disease caused by the bacterium Mycobacterium leprae, which primarily affects the skin, peripheral nerves, respiratory system, and eyes.

• It has a long incubation period, sometimes taking years to manifest symptoms.

Leprosy (Hansen's Disease)

Signs and Symptoms

Early Signs:

• Skin Lesions: Pale or reddish patches that are numb to touch.

• Numbness: Loss of sensation in affected areas.

• Muscle Weakness: Often in the hands and feet.

Progressive Symptoms:

• Thickened Skin: Nodules and thickened dermal areas.

• Eye Problems: Reduced blinking reflex, dryness, potential blindness.

• Ulcers: Chronic skin ulcers, especially on the soles of the feet.

• Deformities: Claw-like hands or drop foot due to nerve damage.

• Loss of Eyebrows and Eyelashes: Common in advanced cases.

Types of Leprosy

Based on the Ridley-Jopling Classification:

1. Tuberculoid Leprosy (TT):

• Few skin lesions, high nerve involvement, strong immune response.

2. Borderline Tuberculoid Leprosy (BT):

• Intermediate between tuberculoid and borderline lepromatous.

3. Borderline Borderline Leprosy (BB):

• Intermediate form with more lesions and moderate immune response.

4. Borderline Lepromatous Leprosy (BL):

• Numerous lesions, weaker immune response.

5. Lepromatous Leprosy (LL):

• Many skin lesions and nodules, poor immune response, more severe.

Etiology

• Causative Agent: Mycobacterium leprae.

• Transmission: Likely through prolonged close contact with an untreated person, possibly via respiratory droplets.

Pathogenesis

• Entry: M. leprae enters the body, possibly through the skin or respiratory tract.

• Spread: Bacteria preferentially infect peripheral nerves, skin, upper respiratory tract, and eyes.

• Immune Response: Depending on the host's immune response, the disease can manifest as either paucibacillary (limited) or multibacillary (widespread).

Treatment

1. Multidrug Therapy (MDT):

• Paucibacillary Leprosy: Dapsone and rifampicin for six months.

• Multibacillary Leprosy: Dapsone, rifampicin, and clofazimine for 12 months.

2. Supportive Care:

• Physical Therapy: To prevent deformities and manage neuropathy.

• Surgical Interventions: To correct deformities and manage chronic ulcers.

• Eye Care: Regular check-ups to prevent blindness.

Prevention:

• Early Diagnosis and Treatment: To reduce transmission.

• Contact Tracing and Screening: Of household contacts.