coli and klebsiella. Staphylococcus, bacillus cereus, clostridium difficile

infants are seldom rachitic, but as soon as the infant begins to put on weight rickets is likely to develop Dark-skinned infants more prone, lack of adequate exposure to sunlight. Classification of rickets 1. Dietary deficiency of vitamin D (commonest). 2. Absorption and metabolic defects - (a) Malabsorption. (b) Chronic liver disease (Poor conversion of vitamin D3 to 25-OH-Cole-calciferol) (c) Renal osteodystrophy (Poor conversion of 25. OH-D3 to 1.25-dihydroxy D3 - active principle of vitamin D3) in chronic renal failure. (d) Calcium wasting - Renal tubular acidosis. (e) Hereditary forms - (i) Vitamin D-dependent rickets (VDDR) - deficiency of 1 -hydroxylase enzyme, autosomal recessive, low calcium type. (ii) Vitamin D Resistant Rickets (VDRR) - Primary defect is phosphorus wasting by proximal tubule (low phosphorus type). Also called type II rickets due to end organ defect. Inherited as X-linked dominant, autosomal dominant or recessive. (iii) Increased turn over of vitamin D metabolites - chronic phenobarbitone and diphenyl hydantoin therapy. Clinical features 1. Head - apparently larger than normal in horizontal diameters, forehead prominent (frontal bosses) and occiput and vault flattened out, hot-cross bun appearance, anterior fontanelle larger than normal and closing delayed, posterior portion of the skull, in the first year may have demonstrable softening on pressure (ping-pong resilience, cranio-tabes). Frequent rocking movements of the head common, face appears small upper jaw being narrow, temporary teeth usually appear late. Excessive sweating over forehead. 2. Thorax- Beading of ribs at the junction of ribs with costal cartilages, best developed in the 4th, 5th and 6th ribs just external to the nipple - rachitic rosary. Sternum unduly prominent producing a "pigeon breast". Horizontal depression corresponding to insertion of the diaphragm below which there is a flaring of the ribs (Harrison's groove), occasionally funnel shaped depression of lower part of sternum. 3. Spinal column - Kyphosis due to weakness of muscles, which disappears if child is suspended from armpits In severe cases after weight bearing - scoliosis. 4. Extremities - Metaphyseal enlargement at wrists and ankles, knock-knee and bow legs, coxa-vara, curving of bones of forearm outwards. Upper to lower segment ratio retarded for age, dwarfism in severe cases. Multiple green stick fractures in severe rickets. Deformities may occur due to malunion "Double-malleolus" at ankle. 5. Ligaments and muscles - relaxed and weak hence deformity of spine, late standing and walking and over extension of knee joints - "acrobatic rickets" 6. Digestive system -Pot-belly due to weakness of abdominal muscles, and ptosis of liver and spleen. 7. Nervous symptoms - Restlessness at night with rocking of head on the pillow. Predisposition to tetanic convulsions. 8. Respiratory system - Adenoid and tonsillar hypertrophy, rhinitis, pharyngitis, bronchitis and bronchopneumonia common. In severe cases, tachypnoea with largely diaphragmatic breathing. 9 .Spasmophilia - Triad of tetany, laryngismus stridulus, and convulsions may be expected in the low calcium type of rickets. Diagnosis Early signs of rickets - (a) Restlessness and irritability. (b) Sweating of head. (c) Head rolling (d) Craniotabes. (e) Beading of ribs. (f) Anterior fontanelle noticeably big. (g) Enlargement of metaphyses at the wrists. (h) Delay in dentition X-ray - (i) Fraying and cupping of distal ends of radius and ulna earliest change. (ii) Diminution in density of bone shaft. (iii) Increased distance between distal ends of bones of forearm and metacarpal bones because of non-calcification of the large rachitic metaphysis. On treatment, Mullers lines seen in the widened space at the site of zone of preparatory calcification is first sign of healing deficiency. (v) Intestinal tuberculosis. (vi) Ulcerative colitis. (vii) Antibiotic-induced diarrhoea and pseudo-membranous entero-colitis. (viii) Chronic liver disease. (ix) Vitamin and trace metal deficiency e. g. vitamin C, zinc. (x) Food allergy e.g. cow's milk, coeliac disease allergy to wheat protein gliadin. (xi) Immunodeficiency and HIV infection. I. Dietetic diarrhoea - (a) Excessive quantity of food - overfeeding. (b) Excess of carbohydrates - Osmotic diarrhoea loose, sour smelling stools Lactase deficiency - Green, frothy, acid stools. (c) Allergy to certain foods or milk intolerance or milk protein allergy (more common with cow's milk). II. Infective diarrhoea - (i) Viruses - Rotavirus - winter diarrhoea preceded by respiratory symptoms and vomiting. Self-limiting. Others - Norwalk virus, astraviruses, Echovirus, Cocksackie, polio, calcivirus. (ii) Bacteria - (a) Pathogenic Enteropathogenic: E. Coli (EPEC), Salmonella, Yersinia, Campylobacter. (b) Toxigenic -V cholera, enterotoxigenic, E. coli and klebsiella. Staphylococcus, bacillus cereus, clostridium difficile. (c) Invasive - E coli, Shigella, Salmonella. (iii) Parasitic - Amoebiasis, giardiasis, algid malaria Cryptosporidium in HIV. (iv) Fungal in PEM, superinfection SYMPTOMS Mild case - Onset with loose diarrhoeal type of stools with sometimes vomiting Gradual increase in frequency of stools, greenish, slightly offensive with mucus, varying in number from 2-3 to 10-12 per day. Slight fever Severe case - Onset moderately severe with or without vomiting. Stools soon become watery and odourless Rapid dehydration as evidenced by thirst, dry tongue,