(1998; 28 pages)
Treatment of lepra reactions
During the course of leprosy, immunologically mediated episodes of acute or subacute inflammation known as reactions may occur in up to 25% of patients with paucibacillary leprosy and as much as 40% in multibacillary leprosy. Clinical indications of a reaction are nerve pain, loss of sensation and loss of function. The reactions may rapidly cause severe and irreversible nerve damage and must always be treated promptly. If a patient does not respond to lepra reaction treatment within 4 weeks or his/her condition deteriorates at any time during lepra reaction treatment, send that patient immediately to the nearest specialist centre. During a lepra reaction, do not interrupt leprosy multidrug therapy. Treatment with multidrug therapy reduces the frequency and severity of lepra reactions.
Type 1 lepra reactions or reversal reactions are associated with the development of M. leprae antigenic determinants. They are delayed hypersensitivity reactions and may occur in both paucibacillary leprosy and multibacillary leprosy. In type 1 lepra reactions, there is a high risk of permanent damage to the peripheral nerve trunks. If the reaction is mild and there is no evidence of neuritis (pain, loss of sensation or function), the reaction should be treated with analgesics, such as acetylsalicylic acid or paracetamol. However, if there is nerve involvement, treat type 1 reactions with analgesics and corticosteroids, such as oral prednisolone. The usual course begins with 40 - 60 mg daily (up to a maximum of 1 mg/kg), and the reaction is generally controlled within a few days. The dose is then gradually reduced weekly or fortnightly and eventually stopped. Most reversal reactions and neuritis can be treated successfully under field conditions with a standard 12-week course of prednisolone but some authorities claim that corticosteroids need to be continued for much longer periods of time.
Type 2 lepra reactions (erythema nodosum leprosum), are associated with circulation and tissue deposition of immune complexes. They are an antibody response or immune complex response to M. leprae antigenic determinants which occur only in multibacillary leprosy. Therapy for type 2 reactions may include analgesics, such as acetylsalicylic acid or paracetamol, and corticosteroids, such as oral prednisolone.
In patients with severe type 2 reactions, who do not respond to corticosteroids or in whom corticosteroids are contraindicated, clofazimine at high doses or thalidomide may be used under close medical supervision. Clofazimine often requires 4-6 weeks before an effect is seen, and therefore must never be used as the sole drug for treatment of severe type 2 reactions. However, it may be useful for reducing or withdrawing corticosteroids from patients who have become dependent on corticosteroids. The clofazimine dose for treatment of severe type 2 reactions is 300 mg daily, which should be given in 3 doses of 100 mg each. The total duration of this high dose of clofazimine should not exceed 12 months. Thalidomide should be avoided in women of childbearing age since it is a proven teratogen. If this is not possible, it is imperative that pregnancy is excluded before this treatment is initiated. Effective contraception must be used during the 4 weeks preceding and following treatment as well as during the treatment period. Should pregnancy occur despite these precautions, there is a high risk of severe malformation of the fetus.