| Page updated 8/1/09 |
 |
| |
 |
| |
 |
Lymphland International Lymphedema Online
| http://www.pon.nic.in/fil-free/Disease.html What is Lymphatic filariasis? Lymphatic Filariasis is the common term for a group of disease caused by lymph dwelling nematode worms such as Wuchereria bancrofti, Brugia malayi and Brugia timori termed as Bancroftian filariasis, Brugian (Malayan) filariasis and Timorian filariasis. Since these parasites affect primarily the lymphatic system of man, the disease caused is also commonly termed as Lymphatic filariasis. Filariasis is mostly a hidden disease. Individuals with filarial infection may be Asymptomatic or Symptomatic Asymptomatic condition: Asymptomatic individuals are those infected but without any detectable clinical symptoms and signs.They may have detectable microfilaraemia or antigenaemia. They may be immune or partially immune to infection. Still others in this group may have subclinical infections(without microfilaraemia), as indicated by the presence of filarial antigens in the blood. Asymptomatic individuals are of two types: Asymptomatic without sub clinical damage Asymptomatic with subclinical damage Sub clinical changes include Haematuria and Lymphatic changes Symptomatic individuals are classified based on the clinical manifestations into ACUTE FILARIASIS The Acute clinical manifestations of lymphatic filariasis are characterized by episodic attacks of lymphadenitis and lymphangitis associated with fever and malaise.Sometimes fever precedes the adenolymphangitis by a few days.Although the fever sometimes precedes adenolymphangitis, fever alone, in the absence of adenolymphangitis, should not be ascribed to filariasis, even when microfilaraemia is present. The main clinical manifestations of acute filariasis are: FILARIAL FEVER Filarial fever is an acute recurrent fever with haedache, malaise, chills, rigors, low to high grade (38-40°),subsiding with sweating and it may closely resemble malaria.Fever persists for 3-5 days. It is usually accompanied by symptomatic lymphangitis and other early signs of filariasis but may occur as fever alone. LYMPHANGITIS AND LYMPHADENITIS Acute lymphadenitis and lymphangitis are characteristic of Bancroftian and Malayan filariasis. The onset is acute, involving a single gland or group of glands within the inguinal, axillary, cervical or epitrochlear regions. This is accompanied by fever; 6-8 hours later retrograde (centrifugal) lymphangitis starts in the glands and spreads peripherally. The lymphatic trunks become painful and cord-like with characteristic red streaks running down the arms or legs. The distal affected limb becomes swollen and oedematous during the attack which may continue for several days accompanied by the fever. Lymphangitis may be confined to the groin glands, testis, spermatic cord (endemic funiculitis) or abdominal varix ruptures, symptoms of peritonitis rapidly develop and may be fatal (abdominal filariais) FILARIAL FUNICULITIS AND EPIDIDYMITIS This is an acute painful inflammation of the spermatic cord and epididymis. This is usually associated with fever and inflammation of testis and painful glands in the groins. Lymphangitis of the spermatic cord gives rise to funiculitis which has been called 'endemic funiculitis'.It is usually accompanied by filarial fever and orchitis. Fluid aspirated from the runica vaginalis is cloudy and contains a number of polymorphonuclear cells and occasional red cells, together with microfilariae. The acute symptoms last a few days but recur at intervals. In sections dead and efferentia causing extensive fibrotic change are found and it is possible, although not yet proved, that this may result in sterility. The end result is a thickened spermatic cord. EPIDIDYMO-ORCHITIS Epididymo-orchitis is an acute painful condition involving the testis and epididymis resulting in some degree of scrotal swelling and redness. It is usually associated with fever, funiculitis and lymphnode elargement in the groin. The onset is sudden with pain radiating to the groin and tendernesss of the testis which may swell to twice its usual size with a boggy feeling on palpation. Orchitis is associated with filarial fever,and recurrent attacks lead sooner or later to hydrocele. FILARIAL ABSCESS Filarial abscesses develop within superficial lymphatics on the limbs or scrotum and at first the symptoms resemble an attack of lymphangitis but the pain and swelling continue, to be followed after some weeks by rupture and a discharge of pus. Pus may be sterile or contain bacteria particularly Beta haemolytic streptococci. Fragments of dead adult worms may be discharged. CHRONIC FILARIASIS Chronic stage of filariasis usually develop 10-15 years from the onset of the first acute attack. The incidence and severity of chronic clinical manifestations tends to increase with age. The main characteristic feature of chronic filariasis is: CHRONIC LYMPHANGITIS Great enlargement of the lymphatic glands with fibrotic changes is common in chronic filariasis. The glands (groin glands usually but, in the Pacific, epitrochlear glands) are enlarged to 5-7.5cm in diameter and may form permanent 'tumours'. On section they resemble an unripe pear, the central portion being fibrotic and the peripheral, glandular. They may contain numerous coiled up adult worms. Varicous groin glands are frequently associated with lymph scrotum chylocele or chyluria. Then a sense of tension or an attack of lymphangitis draws attention to the area where soft swelling are discovered. These swelling may be of insignificant size or they may be as large as a fist. They may be noted on groin and affect the inguinal or femoral glands alone or together. THICKENED LYMPHATIC TRUNK After the initial swelling and inflammation of lymphangitis have subsided a line of induration remains. On excising this thickened tissue and dissecting it, minute cyst-like dilations of the lymphatics have been found containing live or dead adult filariae (but this surgical treatment is not recommended) CHRONIC LYMPHOEDEMA AND ELEPHANTIASIS Swelling of the distal parts of the body appears during acute attacks of filarial lymphangitis and consists of pitting edema which at first subsides completely. After each attack edema increases and subsides more slowly until it finally becomes permanent. The edema eventually ceases to pit and after a period of time becomes firm.The lymphoedema of lower limb is classified into four grades. Grade1: Early oedema completely reversible on elevation. Grade2: Oedema of the limb which is partially reversible on elevation of the limb without thickening of the skin Grade3: Irreversible oedema of the limb with thickening of the skin Grade4: Irreversible oedema of the limb with papillary and nodular growth. When the skin becomes chronically thickened it can be called elephantiasis and this is associated with hypertrophy and fibrous hyperplasia of the subcutaneous tissues. In 95% of cases the lower extremities, either one or both, alone or in combination with the scrotum, or arms are affected. The foot and ankle only, the foot, leg and thigh may each or all be involved, and more rarely the breast, vulva and circumscribed portions of the integuments of the limbs or trunk. LYMPH SCROTUM The scrotum is thickened and the lymphatic varicosities, in the skin are discharging serous serosangineous or milky fluid. Many cases have an associated inguinal or femoral adenopathy. HYDROCELE Hydrocele is the commonest manifestation of bancroftian filariasis among males. Pathologically it is characterized by a distended, generally thickened tunica, vaginalis with hyalinization and fibrosis of the subserosal layer, disorganization of the muscle layers, lymphoid and foreign-body giant cell infiltration, and, in extreme cases, calcification. The hydrocele fluid itself is amber in colour and the sediment shows a characteristic predominance of vacuolated mesothelial cells, fibrin, old blood clots, cholesterol clefts, and calcium dust. Such findings, when associated with epididymal changes, are highly suggestive of a filarial etiology for the hydrocele even without the recovery of W. bancrofti microfilariae from the fluid or adult worms from the cord and epididymal tissues. A majority of these patients do not give any history of ADL attacks in their life time therefore, the progression seems to be a passive phenomenon. CHYLURIA AND LYMPHURIA Chyluria is a condition where the patient complains of passing milky white urine, caused by admixture of lymph with urine due the rupture of lymphatics into the urinary system. Prolonged chyluria may result in the loss of fat in the urine amounting to 15% of lymphatic drainage of the gut. Chyluria will have the same metabloic effects as malabsorption and cause considerable loss of weight with vitamin, electrolyte and other deficiencies. The protein loss in lymphuria may lead to oedema secondary to hypoalbuminaemia. Loss of lymphocytes in prolonged chyluria may lead to low lymphocyte levels which when associated with immunosuppression from drugs may encourage opportunist infections. Chyluria results in pain in the back and aching sensations about the pelvis and groins probably caused by distension of the pre-existing varix. Retention of urine from the presence of chylous or lymphatic clots may be the first indication of trouble. The patient then suddenly becomes aware that he is passing milky urine which may be pink or red; sometimes it is white in the morning and red in the evening or vice versa. Chyluria is likely to occur for the first time, or as a relapse, in pregnancy or after childbirth. The presence of blood is caused by the rupture of small blood vessels into the dilated lymphatics when microfilariae may appear in urine passed during the night time only. OCCULT FILARIASIS The term Occult Filariasis is commonly used to designate filarial infections in which mf are not found in the periphral blood although they may be seen in tissues. However, it has now been shown that in some cases with occult filariasis, mf may actually be found after more careful blood examination despite their low density. Occult filariasis is believed to result from a hypersensitivity reaction to filarial antigens derived from microfilariae.Only a very small proportion of individuals in a community where filariasis is endemic develop occult forms of the disease. The clinical manifestations of Occult filariasis are: TROPICAL MULMONARY EOSINOPHILIA TPE was first described by Frimodty Moller and Barton in 1940. Its main clinical manifestations are: Severe Cough and wheezing (specially at night) Frequent weight loss and fatigue but with minimal or no fever. Restrictive or obstructive lung abnormalities. Abnormal chest radiographs that frequently show diffuse mottled pulmonary interstitial infiltrate. Peripheral blood eosinophilia > 3000 cell/µl Extreme elevation of immunoglobin (IgE) Extreme elevation of anti-filarial antibodies Detection: Using IFAT(Indirect flourescent Antibody Test) Filarial Antibodies are detected. Treatment: Dramatic clinical improvement in response to specific anti-filarial chemotherapy with (DEC) GLOMERULOPATHIES(GLOMERULONEPHRITIS) Glomerulonephritis is associated with lymphatic filariasis. Filarial antibodies have been detected in 2 of 5 children with filariasis and acute glomerulonephritis. Renal biopsy showed diffuse messangial proliferative glomerulonephritis with C3 deposition on the basement membrane. The condition responds well to DEC therapy. ENDOMYOCARDIAL FIBROSIS Endomyocardial fibrosis is a rare diseasee seen in the equatorial belts. The incrimination of filarial infection in its causation is based largely on circumstantial evidence. The geographic distribution of the disease in areas endemic for filariasis, the detection of antibodies to Loa loa in patients with EMF, certain clinical features resembling fialrial infection and the occurance of eosiniphilia and EMF with Loeffler's syndrome have led to the hypothesis of EMF being filarial in origin. Further, Filarial antibodies have been detected in patients with EMF supporting the theory that EMF may be of fialrial origin. FILARIAL ARTHRITIS This is a form of arthritis which usually affects the knee joints and is fairly common in filarial endemic areas. Two types of filarial arthritis have been desbribed clinically 1.Oligoarticular filarial arthritis 2.Filarial pseudo-rheumatism Oligoarticular filarial arthritis: Typically affects just one large joint, most commonly a knee. Synovial fluid from the afffected joint does not contain microfilariae, adult worms or pyogenic organisms. Monoarticular inflammation may reflect a tissue reaction to a filarial worm in the vicinity of the joint. Rarely, lymphatic fistulation into the synovial sac causes chylous arthritis. Filarial pseudo-rheumatism: Less common in lymphatic filariasis than in onchocerciasis. Its pathogenesis involves intra-articular deposition of immune complexes. Intact microfilariae have been detected intra-articularly in some patients with filarial polyarthritis and the local release of proteases by the worms may directly damage synovial tissue. Majority of patients with filarial arthritis do not have fever but a painless swelling of one or more joints (usually the knee). Sometimes the affected joint may be painful, warm and tender with restriction of movement. The symptoms may recur, often in the same joint but occasionally in some other joint and may be mistaken for rhematoid arthritis. It is found that 90% of the patients with filarial arthritis tested are positive for filarial antibodies when tested with mf of W.bancrofti in a fluorescent antibody test These patients show normal or moderately elevated eosiniphil counts and erythtocyte sedimentation rates; X-rays of the involved joints show soft tissue swelling but no bony abnormalities. The antistreptolysin O titre is generally normal. FILARIAL GRANULOMAS IN THE BREAST This manifestaion is particularly prevalent in India and Srilanka where W.bancrofti is the predominant species. It has not been reported from areas endemic for Brugian filariasis. Filarial granulomas present as hard breast lumps attached to the overlying skin and are at times difficult to distinguish from malignant tumours. A histological examination can confirm the diagnosis by the finding of an eosinophilic granulomatous reation around the filarial parasites which are in varying stages of degeneration. Both adult worms and mf have been found in the granulomas. Filarial antibodies have been demonstrated in these patients and the condition responds to DEC therapy which, in many instances, can lead to complete disappearance of the lump. |
