Leprosy Symptoms, Treatment, Types, Causes, Diagnosis

The slow-growing bacteria Mycobacterium leprae causes the infection known as leprosy, also called Hansen's disease. The nerves, skin, eyes, and nasal mucosa could all be affected. With proper treatment and early detection, the illness is curable..

Leprosy was once believed to be a serious and highly contagious disease, but today we know it is not contagious and that treatment is quite effective. But if the nerve damage is left untreated, it can cause blindness, paralysis, and paralysis of the hands and feet.

Read this blog further to get a quick overview of this important topic for dermatology  and ace your NEET PG exam preparation.

CAUSES OF LEPROSY:

Leprosy is caused by a kind of bacteria called Mycobacterium leprae, which has a slow pace of growth. Hansen's disease is another term for leprosy; Hansen was the name of the scientist who discovered M. leprae in 1873.

The precise mode of leprosy transmission is unknown. A person with leprosy may cough or sneeze up droplets that are breathed in by another person and contain the M. leprae bacteria. Close personal contact with a leprous individual increases the risk of infection. It cannot be spread through routine encounters like handshakes, embraces, or sitting next to an infected person while riding the bus or eating at a table.

Pregnant women cannot spread leprosy to their unborn offspring. Additionally, sexual contact cannot spread.

TYPES OF LEPROSY:

The quantity and type of skin sores you have are indicators of leprosy. The type of leprosy determines the specific symptoms and course of treatment. They include:

• Tuberculoid. a milder, less serious variety of leprosy. Only one or a few spots of their skin are flat and light in color (paucibacillary leprosy). Due to nerve damage, the affected  area  feels numb. Compared to other kinds, tuberculoid leprosy is less contagious.

• Lepromatous. a more serious variation of the illness. In this we can find  multibacillary leprosy with extensive skin lumps and rashes, numbness, and muscle weakness. Male reproductive organs, the nose, and the kidneys may also be impacted. It spreads more quickly than tuberculoid leprosy does.

• Borderline. Those who have this kind of leprosy experience both tuberculoid and lepromatous forms.

SIGNS AND SYMPTOMS OF LEPROSY:

Facial deformities

In this we can find :

• Madarosis - loss of eyebrows
• Sagging face
• Buddha's ears
• Rat bitten ears
• Collapsed Pinna
• Saddle nose deformities
• Looks like a lion called Leonine Facies. 

Ocular Involvement

• Lagophthalmos - lower eyelid
• Corneal hypoesthesia
• Superficial punctate keratitis - malaria lepromata (chalk-like clusters)
• Iris pearls: These are clusters of M.leprae.
• The most common cause of blindness in leprosy: cataract

Sanctuary sites 

• Warmer area axilla, groin scalp
• CNS
• Post chamber of the eye
• Lower resp tract
• Female reproductive tract

Unusual presentations of leprosy

• Histoid leprosy 

Comes from spindle-shaped cells in histopathology. nodular discrete lesions on clinically involved skin. This happens because of focal loss of immunity. AFB is longer and more slender. Patients were given Dapsone and monotherapy, which led to this.

Deformities in Leprosy

• WHO classification and grinding
• Hands and feet
• Grade 0: no anesthesia, no visible deformity or damage
• Grade 1: anesthesia present, but no visible deformity or damage
• Grade 2: visible deformity or damage present
• Eyes
• Grade 0: no eye problem due to leprosy, no evidence of visual loss
• Grade 1: eye problem due to leprosy present, but vision not severely affected as a result of these (vision: 6/60 or better, can count fingers at 6m)
• Grade 2: severe visual impairment (vision: worse than 6/60; inability to count fingers at 6 m also includes lagophthalmos, iridocyclitis, and corneal opacities.

Motor Nerve Defects

• Ulnar n-partial claw hand
• Median total claw hand
• Radial wrist drop
• Common peroneal n-foot drop
• Post tibial n-claw toes/ hammer toes
• Facial n-lagophthalmos, facial palsy

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Contact with leprosy

In 95% of cases, there will be no disease. In 5 % of cases, the body is in the indeterminate phase.In 70% of cases, the body will heal. 30% will go to a determinate form of leprosy. If the immune system is high, it will be TT (polar); if the immune system is low, it will be LL (polar). But if an immune system is in between, one can have other unstabilized leprosy called borderline leprosy. The most unstable phase is borderline borderline (BB).

Nerve Involvement in Leprosy

Sensory abnormalities are the most common. First there is Loss of temp followed by loss of  fine touch followed by  pain.  deep touch, vibration, proprioception are not affected.

Q. What nerve can you identify here?

Greater curricular nerve - This nerve is not palpated but seen. 

Q. Most common cranial nerve involved in leprosy? 

Facial and trigeminal 

Q. Most common peripheral nerve involved?

Ulnar

Q. Type of palsy 

Ulnar (High ulnar)

Median (Low median)

DIAGNOSIS OF LEPROSY:

• Slit Skin Smear- Take a 15 mm blade and make an incision 5 mm long and 3 mm deep. Rotate the blade and scrape out of the tissue. Smear the tissue and do ZN staining. These bacilli being acid-fast, do not get colorized, so it appears pink on a blue background.

On Slit Skin Smear: 3 types of bacilli

• Solid M. leprae - It is living once it gets killed, and it remains in the tissue.
• Fragmented - These dead bacilli are fragmented.
• Granular - This dead bacillus can also be in granular form. 

Identification criteria

• Site: Ear lobe
• The density of bacilli in tissue: 10⁴ bacilli/ gm
• Bacteriological Index (BI): density or concentration of bacilli, living and dead bacilli. 

If BI is 1+, then bacillary concentration is very, whereas, in 6+, it is high.So, high BI means the patient has much more bacilli. Bacilli often form clumps, and it is not possible to count. These clusters are called globi, and if these are seen, they are 6+.

• Lepromin Test- It is Delayed type of hypersensitivity reaction. First described by Mitsuda in 1919. It is not for diagnosing leprosy and  it is obsolete now. It is Positive in tuberculoid poles. Early reaction is known as Fernandez and Late reaction is known as  Mitsuda

Treatment of Leprosy

Multi-drug therapy

Same treatment in both Lepromatous and Tuberculoid leprosy. This is to reduce the chances of resistance.

•  One dose of Rifampicin kills 99.9% of bacilli
• Clofazimine
• Dapsone
• Patients are given blister packs to ensure compliance
• Blister pack-  It has medicine for one month, and everything is clearly written. This ensures compliance.The pink blister pack is for adults, and the yellow blister pack is for the child.
• Rifampicin - 600 mg monthly dose / 450 mg monthly for child
• Clofazimine - 300 mg monthly dose / 50 mg alternate for child
• Dapsone - 100 mg of daily dose / 50 mg alternate for child

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