Leprosy, which is now known as Hansen's disease (HD), still ravages many parts of the world, even in developed nations. It is caused by a slow-growing bacterium called Mycobacterium leprae. It affects the skin, the peripheral nerves, and the eyes. It presents in two forms depending on the immune response of the host, namely, paucibacillary and multibacillary leprosy.
The spectrum of clinical manifestations ranges from tuberculoid on the one end to lepromatous leprosy on the other. It is diagnosed by matching the examination findings with the results of a skin smear or biopsy which reveals the presence of the microbes.
Treatment of Leprosy
Early diagnosis and full antimicrobial courses, with prompt treatment of leprosy reactions, now makes a full cure possible in almost every case of leprosy. Thus the treatment of leprosy has evolved greatly from the former method of management i.e., isolation of the leprosy patient.
Early intervention in leprosy mandates widespread awareness of the often subtle manifestations of the disease, and provision of the right drugs at the right time under direct supervision with careful follow-up. Its importance lies in avoidance of serious or disfiguring complications. This not only prevents physical deformity but also future stigma.
Current medical treatment focuses on providing a combination of powerful drugs (multi-drug therapy, MDT) for a period ranging from six months to two years, based on the type and clinical severity of the disease. The establishment of MDT is based on the sound premise that MDT will effectively and rapidly eliminate the bacteria and slow, if not prevent, the development of resistance.
Continuing research has led to the WHO recommendation to reduce the period of therapy from 24 to 12 months.
Important precautions at the start of treatment include:
- awareness of any areas of numbness before starting the antibiotics, to prevent treatment-related nerve damage
- commitment to completing the regimen despite feeling fully recovered is required until the doctor agrees that further treatment is unnecessary.
MDT is supplied free by the World Health Organization (WHO) to all patients with leprosy in endemic countries.
The drugs used in the WHO’s MDT for multibacillary patients include 3 mycobactericidal drugs, namely:
A single dose of rifampicin, dapsone and minocycline has also emerged as a satisfactory therapy for paucibacillary leprosy cases which fulfil specific criteria. However, early recognition and initiation of treatment is required.
Serious side effects are uncommon, but some relatively minor adverse effects may cause social and emotional distress. For instance, clofazimine produces darkening of skin tone, and scaling, which can lead to social rejection, recognition of the diagnosis by other people, or lead to a perception that the person has some serious illness. In societies comprising a dominant white-skinned category, this change in skin tone may trigger racial discrimination as well, in terms of social and workplace interactions and opportunities.
Other drugs used in leprosy treatment, as in situations of drug allergy, include:
Monotherapy of leprosy is prohibited as it inevitably leads to the emergence of drug resistance, making further treatment difficult and prolonged, as well as having important public health consequences.
Management of Leprosy Reactions
HD shows typical immunologic reactions during which disease manifestations become much more intense.
They are classified into type 1 (reversal), and type 2 (erythema nodosum leprosum) reactions.
These are not confined to any specific period of treatment, and may precede its start.
They are not an indication for pausing therapy. They are treated by different agents, such as:
- corticosteroids which are first-line agents especially when nerve integrity is threatened by enlarging granulomas
- tumor necrosis factor inhibitors
- T lymphocyte inhibitors
Treating leprosy reactions in a timely and effective manner is crucial in avoiding sensory loss and mutilation.
Pain, inflammation, and neuritis, should all be managed in such as way as to reverse and prevent nerve damage.
Corticosteroids along with continued MDT are usually preferred. Non-steroidal anti-inflammatory drugs (NSAIDs) are used in mild reactions. Steroids should be tapered over 12-20 weeks to avoid rebound inflammation.
Clofazimine is a more long-term agent. Cyclosporine or methotrexate are immunosuppressants which may be substituted for steroids when required, as in cases of steroid allergy or when severe adverse effects develop with corticosteroid therapy.
Despite the general effectiveness of these regimens, late relapses or reactions may still occur in the paucibacillary form, while M. leprae has been known to persist, either dead or alive, in the multibacillary form.
Management of Sensorimotor Loss
When a peripheral nerve loses function for six months or more it is termed permanent nerve damage.
In such patients, care is taken to teach them how to cope and to prevent future harm as a result of sensory dysfunction. This involves measures such as:
- Helping to keep the eyes moist with artificial tears, frequent voluntary blinking, eyelid closure, and sunglasses
- Daily inspection of the extremities and the eyes for wounds, which should be covered by sterile cloths
- Skin care all over the body
- Daily exercises to maintain flexibility and prevent joint contractures
- Preventing or limiting ulceration of the lower limbs associated with Charcot joint (neuropathic joints) by keeping off the feet, using customized footwear, and daily inspection
- Watching for skin and soft tissue infections as a result of permanent nerve damage, and treating promptly with the right antibiotics
- Surgical intervention as required by debridement and pus drainage, and reconstruction of damaged tendons, corneal transplant, or release of contractures
- Recognizing and treating chronic leprosy reactions
It is essential to provide continuing vigorous education to patients and to their families, as well as to the community at large, about the causes, effects, and curable nature of the disease, as well as its low rate of transmission.
MDT, in fact, ensures that lepromatous patients lose all ability to transmit the bacilli within 72 hours of the start of treatment.
Community-based programs of socioeconomic rehabilitation are most effective among all measures in ensuring that the patient can enjoy as full a life as possible during and after treatment.
Again, deformity is not an inevitable part of the disease. It can, and in fact, should, be averted by timely presentation for diagnosis and treatment of leprosy patients.
This should become a community goal, with the treatment of patients being driven by compassion rather than fear.
Social integration of treated patients, whether they have suffered deformity or not, should be encouraged in every way since they are non-infectious.
The notion of hereditary, sexual, or social transmission should be vigorously debunked by repeated education. Most patients, in fact, have no history of contact with another leprosy patient.
Reviewed by Afsaneh Khetrapal BSc (Hons)