Reactions In Leprosy

REACTIONS IN LEPROSY DEFINATION: Reactions represent episodes of acute hypersensitivity to antigens of M.Leprae brought about by disturbance in the pre-existing immunological balance. CLASSIFICATION: 1. Type I reactions associated with cell mediated hypersensitivity

2.

Type II reactions associated with immune complexes.

TYPE I reactions:

• •

• • • •

Synonym: reversal reaction, borderline reactions, tuberculoid reactions, non lepromatous reactions. This is a delayed type hypersensitivity reaction which is an example of type IV hypersensitivity reaction. Mechanism: antigens from breaking down leprosy bacilli reacts with T lymphocytes and this is associated with a rapid change in the CMI. This typically occurs in borderline leprosy because of their immunological instability and if the reaction is associated with rapid increase in specific CMI, as in patients under treatment, we speak of upgrading reaction or reversal reaction. CLINICALLY THE MOST IMPORTANT SIGN IS A RAPIDLY DEVELOPING CHANGE IN THE APPEARANCE OF SOME OR ALL THE SKIN LESIONS. Skin lesions are -----

   

   

 

•

• • •

• •

Edges become more prominent ---- the LESIONS STAND OUT SHARPLY FROM THE SARROUNDING NORMAL SKIN. Often tender or even painful New lesions may appear. Usually they resemble the pre-existing ones, but sometimes they are numerous and small. IF THE REACTION IS VERY SEVERE, THE SKIN LESIONS MAY DESQUAMATE OR EVEN ULCERATE. As the skin reaction subsides, it becomes dry and scaly and ultimately flattens leaving a wrinkled hypo pigmented surface. If the reaction has been severe, there may be scarring.

Neuritis is the most important part of type I reaction. It presents as ----- Independently or with skin lesions  It is more common in men with BT lesions



•

More eythematous ---- sometimes purple or in white skin ---- coppery brown. Occasionally they are edematous and pale. Swollen Shiny Warm

   Severe    

It presents CLASSICALLY AS TENDER ENLARGEMENT OF NERVES AT THE SITES OF PREDILECTION. Sometimes grossly swollen especially ulner nerve which may develop a nerve abscess. Loss of function may be marked with sudden paralysis of the hand and foot, wrist drop, foot drop, lagopthalmos. Anesthesia develops rapidly in the distribution of the affected nerve. Sometimes there is almost no tenderness but slight increase in muscle weakness or anesthesia. reactions are accompanied by systemic illness characterized by ----low grade fever malaise anorexia Slight to severe edema of the face, hands and feet.

Reactions are most common in BT leprosy even without chemotherapy. They start within 2 weeks and 6 months of start of therapy. In BB leprosy also the reactions occur early. But longer intervals are recorded in BL leprosy. Untreated BT patients may suffer episodes of type I reaction in association with downgrading, presumably because the immunological balance is responding to an increasing antigenic stimulus. In this case, the reactions cease as the patients reaches BL but are likely to recur during chemotherapy. Other factors that upset the balance and precipitate the reactions are ---- Pregnancy  Intercurrent infections especially tuberculosis  Vaccination  Psychological stress. Untreated Type I reactions tend to last for months or years and may even relapse. Even with treatment, their potential to recur persists so that anti-inflammatory treatment must frequently be continued for several months. TREATMENT:  Remove any precipitating factors  Continue MDT

   

Reduce stress ------ mental and physical Sedatives Analgesics. Steroids are the treatment of choice



Chloroquine and antimonials have sometimes been used for mild reactions where neuritis and ulceration are not there. Only Aspirin may suffice in these in conditions



The dose depends on the severity of the reaction. Usually at least 60-80 mg daily as single morning dose should be given. If the symptoms are not controlled or markedly improved within 24-48 hours, the dose should be increased in 20-40 mg per day increments depending on the severity of the condition. The dose of prednisone should then be

maintained until the skin changes have completely resolved, neuritic pain has cleared and neural function has begun to return. At this point attempt to taper. This is usually done as reduction of 5 mg every 1-2 weeks. If the reaction is severe, then the tapering should be slow whereas if the reaction is of moderate severity, rapid tapering may be possible. Furthermore if an exacerbation is noticed at any point, the dose is raised to control it again and tapering later resumed on a slower schedule.



A trial of clofazimine should be considered in occasional patient whose type I reaction requires prolonged daily high dose prednisolone therapy. The patient is given as 300 mg daily and after 2-4 weeks an attempt is made to begin tapering the prednisolone again. If it is unsuccessful, it may be deferred for 2-4 more weeks and tried again. It may be possible to discontinue steroids in 6-12 months. MOST PATIENTS WILL HAVE SOME GI SIDE EFFECTS ON TAKING THIS MUCH CLOFAZIMINE. Its dose should be discreased if the GI complaints steadily increase in severity. Even if there are no serious complaints, the dose should be tapered to 100 mg per day within 1-2 years.

TYPE II lepra reaction: •

•

•

It occurs in multibacillary disease and It causes acute inflammation in any organ or tissue harboring M.Leprae. It differs from reversal reaction in several ways ------------ It is a type III hypersensitivity reaction and thus it is a humoral antibody response. Reversal reaction is a delayed type hypersensitivity reaction.  It occurs most exclusively in lepromatous leprosy, only occasionally appearing in BL.  The clinician sees no change in the pre existing lesions, but may see crops of brightly erythematous nodules which come and go.  Systemic disturbance is usual  It tends to occur later during the course of treatment when the skin lesions appear quiescent and all or most of the bacilli in the skin are granular. However the patients may be in reaction when first seen. One of the manifestations of type II reaction is the skin lesions of ENL ---- probably the most common. This presents as -------SMALL, 2-5 mm PAPULES OR LARGER NODULES WHICH ARE PAINFUL AND TENDER TO TOUCH. They may be superficial and stand out clearly from the skin or may be placed deeply and may be palpable rather than visible. THEY ARE DOME SHAPED WITH ILL DEFINED MARGINS AND PINK/RED/DUSKY BROWN. The red color is blanchable. The ENL lesions tend to recur in the same sites. The papules may turn into pustules and discharge white pus (containing PMN leucocytes and degenerate AFB) or may simply ulcerate. When ENL lesions fade, they leave a blue stain in the skin. THEY DIFFER CLINICALLY FROM THE TYPE OF ERYTEHMA NODOSUM SEEN IN CONITIONS LIKE TB, Sarcoidosis and acute rheumatism by the fact that -----

 

THEY ARE EVANESCENT -----LASTING ONLY 2-3 DAYS. If they do not resolve completely, a chronic painful panniculitis develops which may persist for months or years. Large areas of inflamed skin and SC tissue then becomes fixed to the underlying fascia, muscle, bone and may thus immobilize the part. The area ulcerates with the slightest trauma and HEALS WITH DIFFICULTY. They are more numerous



• • • •

They occur in areas besides the shin ------ mostly face and extensor surfaces of limbs. In fact it can occur in any area where there has been a lepromatous infiltrate except the hairy scalp, axillae, groins and perineum. ENL is more severe in Caucasians and Mongoloids ----- more severe and rapid ulceration. Unusual forms may be seen ------- e.g. blood filled blisters around the edges of soles and palms. Neuritis is often present. But it is less dramatic then type I. Other features include ---- iritis  episcleritis  orchitis  lymphadenopathy ---- rarely necrosis and discharge through the skin  epistaxis  palatal perforation  bone pain ------- usually confined to the tibia and there is exquisite tenderness and a boggy feel when palpated  oedema of the face, hands and feet.  Hands and feet may be acutely and painfully inflamed.

Signs and symptoms H/O trauma or irritation Blurring of vision photophobia

conjunctivitis common no no

Iridocyclitis No Yes Yes

Type of pain

No, only itchy or gritty sensation

Deep pain

Tint of redness Distribution of redness

Bright red Peripheral

Less central

exudate tender Pupil size and response

Usually present no normal

Nil Yes Small, sluggish

•

Systemic features------ Fever (40 degree) usually in the late afternoon and remits  Exhaustion by pain  Headache

  

Anorexia Insomnia Depression



Proteinuria

•

Factors        

•

TREATMENT :  Aspirin ---- alone effective in mild cases  Sedation





• • • •

•



that precipitate Type 2 reaction are -------Intercurrent infection Injury Surgical operation Physical stress Mental stress Immunization Pregnancy and parturition Ingestion of KI and of anti-leprosy drugs.

Prednisolone --- should always be used when a neuritis threatening permanent nerve damage is present. It is used for severe reactions but the doses are less than type I. 60 mg will control most reactions and tapering should be done more quickly. The problem is likely to be chronic especially in patients with high bacterial count. This may require therapy regularly or intermittently for years. In such cases, clofazimine is clearly useful if the patient can tolerate its side effects. Once control is achieved, the drug should be gradually lowered to 100 mg daily temporarily increasing it again if reaction exacerbates. Although clofazimine and prednisolone are the treatment of choice for ENL, thalidomide is the DOC ------- see drugs for details. Thalidomide may occasionally fail to control ENL. the explanations are ------

The reaction may not be ENL. It may be type I reaction which does not respond to thalidomide. The patient is non-complaint to treatment ENL occurring in borderline cases may not respond to thalidomide. In these cases response is observed if steroids are started initially.  Other drugs ---Chloroquin ------ controls mild to moderate ENL. It is started at a dose of 250 mg thrice daily which should be sufficient to control the reaction within a week. It is then lowered to 250 mg BD for a week followed by 250 mg daily. Even 250 mg every other day can control. Antimonials ---- Pottasium antimony tartrate must be given IV. The usual starting dose is 30 mg given as 0.5-1% solution IV. This may be repeated every other day and the dose may gradually be increased to 60 mg. the total dose should not exceed 500-600 mg. if no response is seen after 6 injections ---- discontinue. For intramuscular use, STIBOPHEN is preferable.

LUCIO PHENOMENON: • This is a type of reaction confined to the diffuse non-nodular form of LL which is chiefly encountered in Mexicans called Lucio leprosy. • It is seen only in untreated cases. • It was first described by Lucio and Alvarado in Mexico in 1852; they called it ‘lepra manchanda’.

• • • •

Initially painful and tender pink lesions appear on the skin, usually on one of the limbs ---- they become purpuric ---- the centre becomes necrotic and ulcerated and finally develops a brown or black crust (eschar) which falls off after a few days to leave a superficial atrophic scar. On the legs the lesions are larger and are more inflamed and develop bulla which burst leaving a deep ulcer with jagged edges which heal slowly if at all. Although steroids (relatively high doses are needed for initial control and tapering the patient off them may require several years) have good effect, thalidomide is of no use. Good results are obtained with dapsone and excellent with rifampicin. The feature that distinguishes Lucio phenomenon from ENL is ishaemic epidermal necrosis, NECROTIZING VASCULITIS OF THE SMALL BLOOD VESSELS OF THE UPPER DERMIS, severe focal endothelial proliferation of the mid dermal vessels and by the presence of large number of bacilli in endothelial cells.