A30.5 Lepromatous leprosy

Name of the Condition

• Lepromatous leprosy

Summary

Lepromatous leprosy is a severe form of leprosy caused by Mycobacterium leprae, characterized by widespread skin lesions, extensive nerve damage, and systemic involvement. It represents the polar end of the leprosy spectrum, with a weak immune response to the bacteria, leading to high bacterial loads and progressive tissue damage. The condition progresses slowly but can cause significant disability if left untreated, affecting the skin, peripheral nerves, mucous membranes, and other organs.

Causes

Lepromatous leprosy is caused by infection with Mycobacterium leprae, the bacterium responsible for leprosy. Transmission occurs through prolonged close contact with an untreated individual, typically via respiratory droplets. The bacteria invade the body and multiply slowly, primarily affecting cooler regions such as the skin and peripheral nerves. The host's impaired immune response allows the bacteria to spread widely, leading to the characteristic manifestations of this form.

Risk Factors

• Prolonged exposure to an untreated person with leprosy.
• Residence in or travel to regions with high leprosy prevalence (e.g., parts of Asia, Africa, and South America).
• Weakened immune system, which may increase susceptibility to severe disease.
• Genetic factors that influence the body's immune response to the bacteria.

Symptoms

• Diffuse, symmetric skin lesions (macules, papules, or nodules) with reduced sensation.
• Thickened nerves, particularly in the face, elbows, and knees.
• Nasal congestion, epistaxis, or ulceration of the nasal mucosa.
• Eye involvement, including lagophthalmos or corneal anesthesia.
• Muscle weakness or paralysis, especially in the hands and feet.
• Systemic symptoms such as fever, weight loss, or lymphadenopathy in advanced cases.

Diagnosis

Diagnosis is based on clinical evaluation, including the presence of characteristic skin lesions and nerve thickening, and confirmed by skin biopsy or slit-skin smear showing acid-fast bacilli. Histopathology typically reveals a diffuse infiltrate of foamy macrophages and numerous bacilli. Laboratory tests, such as PCR or serology, may support the diagnosis but are not definitive. The Ridley-Jopling classification helps distinguish lepromatous leprosy from other forms based on clinical and histological findings.

Treatment Options

Treatment involves multidrug therapy (MDT) with rifampin, dapsone, and clofazimine, administered for 12 months or longer. Adjunctive therapies, such as corticosteroids, may be used for nerve inflammation or reactions. Regular monitoring for treatment response and adverse effects is essential. Physical therapy and rehabilitation may be needed to manage nerve damage and prevent deformities.

Prognosis and Follow-Up

With early and consistent treatment, lepromatous leprosy can be controlled, but nerve damage and deformities may be irreversible. Long-term follow-up is required to monitor for relapse, reactions, or complications. Patients should be educated on self-care to prevent injuries and manage symptoms. Regular skin and nerve assessments help track disease progression and treatment efficacy.

Complications

• Permanent nerve damage leading to sensory loss, muscle weakness, or paralysis.
• Deformities of the hands, feet, or face due to untreated nerve involvement.
• Secondary infections from skin lesions or impaired sensation.
• Eye damage, including blindness, from corneal anesthesia or lagophthalmos.
• Respiratory complications from nasal mucosa involvement.

Lifestyle & Prevention

• Avoid prolonged close contact with untreated individuals in high-prevalence areas.
• Practice good hygiene and wound care to prevent secondary infections.
• Use protective measures, such as masks, in endemic regions.
• Seek early medical care for suspicious skin lesions or nerve symptoms.
• Follow public health guidelines for leprosy control and prevention.

When to Seek Professional Help

Seek immediate medical attention if you experience:

• New or worsening skin lesions with reduced sensation.
• Numbness, tingling, or weakness in the hands or feet.
• Nasal symptoms, such as bleeding or congestion.
• Eye pain, redness, or vision changes.
• Unexplained weight loss or systemic symptoms.

Tips for Medical Coders

When coding for lepromatous leprosy (A30.5), ensure documentation supports the diagnosis, including clinical findings (e.g., diffuse skin lesions, nerve thickening) and diagnostic tests (e.g., biopsy, slit-skin smear). Note the specific form of leprosy and any associated complications or treatments. Verify that the code aligns with the patient's clinical presentation and follow coding guidelines for infectious diseases.