What is leprosy (Hansen's disease)?

From the Guidelines

Leprosy, also known as Hansen's disease, is a chronic infectious disease caused by Mycobacterium leprae that primarily affects the skin, peripheral nerves, and mucous membranes. This condition is characterized by a spectrum of clinical forms, reflecting the cellular immune response to the bacteria, as described in the study by 1. The major forms of the disease include lepromatous, tuberculoid, and indeterminate lesions, with distinct features such as erythematous papules, nodules, or infiltration of the skin, as noted in the studies by 1 and 1.

Key Characteristics of Leprosy

• A chronic bacterial disease that primarily affects the skin, peripheral nerves, and mucous membranes
• Characterized by a spectrum of clinical forms, including lepromatous, tuberculoid, and indeterminate lesions
• Lepromatous form is marked by a number of erythematous papules and nodules or an infiltration of the face, hands, and feet with lesions in a bilateral and symmetrical distribution
• Indeterminate form is characterized by early lesions, usually hypopigmented macules, without developed tuberculoid or lepromatous features

Diagnosis and Treatment

Diagnosis of leprosy can be confirmed by demonstrating acid-fast bacilli in skin or dermal nerve, obtained from the full-thickness skin biopsy of a lepromatous lesion, as stated in the study by 1. Treatment requires a multidrug therapy (MDT) approach to effectively cure the disease, although the specific regimen is not mentioned in the provided studies. It is essential to note that leprosy is not highly contagious, requiring prolonged close contact with untreated patients for transmission, and that early diagnosis and complete treatment are crucial to prevent disability and stop disease transmission.

Importance of Early Diagnosis and Treatment

• Early diagnosis and complete treatment are crucial to prevent disability and stop disease transmission
• Leprosy is not highly contagious, requiring prolonged close contact with untreated patients for transmission
• The disease damages nerves, leading to loss of sensation that can result in injuries and deformities if left untreated
• Regular follow-up during and after treatment is essential to monitor for complications, relapse, or drug side effects

From the Research

Definition and Overview of Leprosy

• Leprosy, also known as Hansen's disease, is a chronic infectious disease caused by Mycobacterium leprae that primarily affects the skin and peripheral nerves 2, 3.
• It is a specific infection that has been reported for more than 2000 years, with a global prevalence rate of less than 1 patient per 10,000 population achieved in the year 2000, but still more than 200,000 new cases are reported each year 2.
• The disease has various presentations, including paucibacillary and multibacillary forms, which are correlated with the patient's immune response, bacillary load, and delay before diagnosis 2.

Characteristics and Transmission

• Leprosy is a chronic infection that primarily affects the skin and peripheral nerves, and Mycobacterium leprae is one of the last bacterial species of medical interest that cannot be cultured in vitro 2.
• The transmission and pathophysiological data of leprosy are still limited, but it is known to be prevalent in tropical countries 3.
• The disease can cause significant morbidity, including skin lesions, nerve damage, and disability, if left untreated or poorly managed 4, 5.

Treatment and Management

• Multidrug therapy (MDT) is the recommended treatment for leprosy, which includes a combination of dapsone, rifampin, and clofazimine for paucibacillary and multibacillary forms of the disease 4, 2, 5.
• The treatment regimen typically lasts for 6 months for paucibacillary leprosy and 12 months for multibacillary leprosy, and is available free of cost at government health facilities 5.
• Alternative regimens, such as rifampin, moxifloxacin, and minocycline (RMM), have been studied and shown to be effective in treating leprosy, with improved safety profiles and treatment adherence 4.
• The World Health Organization (WHO) recommends MDT as the standard treatment for leprosy, and it has been shown to be safe and effective in reducing the prevalence of the disease 2, 5, 6.