lesion but mostly will have changes of structural damage to the kidneys

pregnancy, allergic reactions to insect bites, pollens and vaccines, renal artery stenosis Pathology - The kidneys are large, pale and soft. Biopsy studies show a wide variety of histopathological changes - (a) Minimal change nephropathy is common in very young children. (b) Focal glomerulosclerosis. (c) Membranous nephropathy. (d) Proliferative glomerulosclerosis - accounts probably for the largest group of adults with idiopathic nephrotic syndrome. Clinical features - 1. Age and sex - Two to three times more common in childhood with peak incidence at 2-3 years. In this age group there is a male: female ratio of 2. 5: 1, in adults, sex incidence is equal. 2. Oedema - Oedema is peripheral involving the limbs, particularly lower limbs. In children oedema may be more obvious in the face and abdomen. Usually massive generalised anasarca, the patient almost weighing double his true weight. Intense oedema of the scrotum or vulva may occur. There may be bilateral hydrothorax. Oedema may persist for many weeks or months. Spontaneous subsidence with diuresis (nephrotic crisis) may occur, to be followed again by increase of oedema. 3. Gastro-intestinal symptoms-Anorexia causes severe malnutrition. Diarrhoea and vomiting due to oedema of intestinal wall. 4. General symptoms - Prolonged protein loss causes anorexia, lethargy, tiredness, frequent infections and muscle wasting Dyspnoea may occur if there is fluid in the pleural cavity. 5. Blood pressure - There may be periods of hypertension; ultimately with development of chronic nephritis permanent hypertension may develop. Laboratory findings - 1. Urine - (i) Oliguria while oedema is forming, diuresis or normal amount of urine during period of subsidence of oedema. (ii) Proteinuria - Massive, usually more than 5 g/day though variable from time to time, urine becomes almost solid on boiling. Daily loss of protein may be 20-50 g. (iii) Red blood cells absent or few. (iv) Casts - Fatty casts, tubular cells, oval fat bodies, doubly refractile bodies. 2. Blood - (i) Anemia -slight, normochromic. (ii) Hypoalbuminemia - Serum albumin usually less than 3 g/100 ml. Total serum globulin concentration frequently lowered with often elevation of 2 and globulins. (iii) Hyperlipoproteinemia (LDL level in particular) and hyperfibrinoginemia (contributing to raised ESR). s 3. Renal biopsy - of value in diagnosing the cause and in judging prognosis. Indications - (a) Usually necessary in patients over the age of 10 years. Majority of childhood nephrosis below 10 show minimal change pattern. (b) Presence of hematuria. (c) Hypertension. (d) Reduced renal function in absence of severe hypovolemia. (e) Lowered serum complement level. (f) Non-selective differential protein clearances. If one or more of these signs is present it is very unlikely that the patient has a 'minimal change' lesion but mostly will have changes of structural damage to the kidneys. Differential Diagnosis - 1 From acute nephritic syndrome - Acute nephritic syndrome 2. Of conditions causing nephrotic syndrome - Cases due to diabetes, anaphylactoid purpura, drug therapy or irradiation of the kidneys can be diagnosed from the history or other typical findings Amyloid disease - history of chronic suppuration; factors in plasma including fibrinogen and factor VIII. 3. Impaired resistance to infection - Cellulitis, primary peritonitis with pneumococci, urinary tract infection. 4. Acute hypovolemia - may occasionally be severe enough to precipitate renal failure. 5. Hyperlipidemia - probably increased atherogenesis. Prognosis - With minimal lesion nephrotic syndrome about 90% of children respond to prednisolone In adults the response rate is about