Lepra reactions

dermatology in general medicine

1. LEPRA REACTIONSINTRODUCTION- Reactions occur due to abrupt change in immunological response of the body against M. leprae.Leprosy reaction can develop at anytime, at Onset of the disease before starting the treatment During treatment After completion of the treatmentPersons with following features are more likely to develop reactions:  Multiple lesions  Lesions close to the peripheral nerve (predisposes to neuritis)  Lesions on the face  People with nerve thickening with / without functional impairment (including thickening) Reaction precipitating factors:  Infections and infestations  Vaccination  Hormonal changes: Puberty, Pregnancy & Childbirth  Psychological stress TYPES OF REACTIONSThere are two types of Leprosy reactions. (1) Type 1 Reaction: Also called Reversal Reaction can occur in any patient with unstable CMI (2) Type 2 Reaction: Also called Erythema Nodosum Leprosum (ENL) occurs in patients with MB leprosy having a heavy load of bacilli

2. Type 1 reactions ( TYPE IV HS)Occur both in PB and MB leprosy. Cause: It occurs as a result of increased activity of the body’s immune system, particularly cell mediated immune response Clinical presentation Reaction may be the first presenting sign of the disease .Signs of inflammation are seen in the existing skin lesions i.e. skin lesions become red, more prominent, swollen, shiny and warm. Appearance of new skin lesions: Some previously unnoticed or non visible patches may become visible, giving an impression of appearance of new skin lesions. Inflammation of nerves: Nerves are frequently affected in type 1 reaction

3. Acute Neuritis: Existing involved or new nerves become enlarged, painful/tender and their sensory, autonomic and motor functions get affected. Silent neuropathy /quiet nerve paralysis: Sometimes, nerve function may get affected without any pain or tenderness of the nerve or inflammation of skin lesions these patients need to be identified early and treated with corticosteroids.
TYPE 2 REACTIONS OR ENL (TYPE III HS)Patients having high load of leprosy bacilli as in Multi- bacillary/ infiltrative type of leprosy get type 2 reaction. Type-2 reaction can involve multiple organs & systems, causing generalized symptoms. Cause: It occurs when large numbers of leprosy bacilli are killed, followed by release of their antigens. These antigens from the dead bacilli provoke an arthus type allergic reaction General condition: fever, headache and body ache Skin lesions: Type 2 reactions exhibit the typical signs of erythema nodosum - red, firm, painful, tender evanescent cutaneous and subcutaneous Rarely they can break down and suppurate / necrose producing Erythema Nodosum Necroticans (ulcerative ENL). Inflammation of nerves: Nerves may also get affected in type 2 reactions.Eyes-iritis , iridocyclitisOrchitisArthritisSwelling of hands and feetDactylitisGlomerulonephritisRarely- hepatitis endocarditis

4. Diagnosis1) Clinical-Consider Reaction on  Sudden appearance of symptoms  Inflammation of existing skin lesions (type-1 reaction) or appearance of painful tender nodules (type-2 reaction)  Inflammation of nerves  Involvement of ocular tissue  Swelling of hands, feet and pain in small joints2) Slit skin smear3) HistopathologyTreatment 1) reassurance2) bed rest3) rest to affected nerve- splint may be required4) continue MBMDT5) NSAIDS in mild cases6) oral steroids in severe cases For Type 2 reactions- apart from above medications, clofazimine, thalidomide also given