Leprosy/Hansen Disease: Management of reactions and prevention of disabilities

Overview

Leprosy is an uncommon but widespread disease, with over 200 000 new cases per year, globally. Leprosy is unusual in that many of the most problematic complications occur as a result of the host’s immune response to the infecting organism, Mycobacterium leprae. These intermittent and recurring inflammatory episodes are known as leprosy reactions. They appear in two distinct forms, with differing underlying immuno-pathology, clinical features and treatment requirements. The involvement of certain peripheral nerves (neuritis) often leads to disability and devastating psychosocial consequences.

Reactions occur with varying frequency and severity. In some settings, as many as 50% of patients may be affected. Because leprosy is a disease of poverty, access to expert care in referral centres is often not possible.

Several important tasks remain, however, in the fight to prevent disability from leprosy. The first priority remains early case detection, so that treatment can begin as early as possible after symptoms appear. Secondly, it is important to recognize and manage leprosy reactions and neuritis effectively, so that nerve function is preserved. A third task is the primary prevention of leprosy, which is gradually being developed as a working possibility. All of these tasks must be carried out at the peripheral level if they are to be of worthwhile benefit to the at-risk population.

The objective of this Technical Guidance document is to review current management practices for leprosy reactions and neuritis and to describe ways in which they can be improved, so that national programmes can achieve their goals of preventing and minimizing disability due to leprosy.

Reactions are acute exacerbations of the signs and symptoms of leprosy occurring during the natural course of the disease as well as during or after treatment. They result from the body’s immune response to M. leprae. They can affect the skin, nerves, eyes or limbs. Left untreated or improperly managed, reactions can lead to severe nerve function impairment and subsequently to disabilities. Reactions constitute the main pathway by which leprosy causes nerve damage and disability. Effective management of reactions is thus the key to preventing disability. The diagnosis of reactions requires certain clinical skills; effective treatment requires careful judgement, as the clinical course is rarely straightforward.

Managing reactions typically involves the four following steps:

• (1) Recognizing that a reaction is occurring in a person known to have leprosy, remembering that a reaction may already be present at the time of diagnosis.
• (2) Assessing the situation accurately, in particular testing nerve function.
• (3) Prescribing and starting the correct treatment.
• (4) Follow-up, monitoring and adjusting the treatment, according to the response.

This document presents updated guidance on the diagnosis and management of reactions in different settings. The focus should be on the peripheral nerves and their functioning. The goal for national programmes should be to improve the level of nerve function assessment across all facilities where leprosy is treated, including in remote areas, where standards are likely to be lower.

Other languages:
Lèpre / Maladie de hansen: Prise en charge des réactions et prévention des infirmités