Hypervitaminosis d

Hypervitaminosis D is almost always iatrogenic, due to erroneous ingestion of large doses of vitamin D during treatment of rickets. Rare cases may be related to prolonged formula feeding in preterms.

Serum vitamin D levels gt;100 ng/mL are considered as toxic, though levels between 50-100 ng/ml should also alert the physician to avoid further vitamin D supplementation.

Clinical manifestations develop after 1-3 months of overdose, with:

• Hypercalcemia, leading to:

- Irritability, anorexia, vomiting, and constipation,

- Cloudy cornea, retinopathy and aortic stenosis.

[**] Hypercalciuria, leading to:

- Impaired urinary concentration with polyuria, polydipsia, dehydration and failure to thrive,

- Nephrocalcinosis with pallor, hypertension and progressive renal failure.

Diagnosis depends on history, hypercalcemia, hyper- calciuria and radiological abnormalities, e.g. generalized osteoporosis and metastatic calcifications in soft tissues. X-ray knee shows deposits of dense bone, producing the typical spectacle sign. ECG may suggest myocardial damage with ST elevation.

[††] Decreased absorption in:

- Acrodermatitis enteropathica

- Chronic diarrhea and malabsorptive states

• Increased urinary excretion in:

- Chronic renal or liver disease

- Hypoalbuminic states, e.g. kwashiorkor

- Massive tissue injury, e.g. burns

- Iron chelation therapy, e.g. in hemolytic anemia Clinical features of zinc deficiency include:

• Failure to thrive, IUGR and hypogonadism

• Chronic diarrhea and anorexia

• Eczematous skin lesions and alopecia

• Increased infections and delayed wound healing.

Acrodermatitis enteropathica is an autosomal recessive defect in zinc absorption due to defective zinc transporter protein (ZIP4), which usually manifests during or after weaning with: (a) growth failure, (b) chronic diarrhea, (c) eczematous skin lesions, mainly on acral (hands/feet), inguinal and/or flexural parts of body, and (d) alopecia.

Fluid therapy in children requires precise calculations of fluid/electrolyte requirements, as the volume, composition and rate of administration for parenteral fluids varies with indication, circulatory status and laboratory values of electrolytes. Important determinants for initial fluid therapy include:

• Whether patient is dehydrated or requires only maintenance therapy?

• If dehydrated, what is its severity and type?

• What is the source of fluid loss?

• Whether and which electrolyte abnormalities are present?

[§§] What is the state of renal and cardiac functions?

Standard fluid therapy is based on the type and severity of the dehydration as follows:

Isonatremic dehydration, the commonest type of dehydration, is characterized by fluid loss from both ECF and ICF in a ratio of ~60:40. More acute is the dehydration, greater is the proportion of ECF losses.

Parenteral fluid therapy in these cases aims for: (a) rapid correction of ECF-deficit and restoration of plasma volume in first few hours followed by, (b) slower correction of remaining deficit plus infusion of maintenance and concomitantly lost fluids, till oral rehydration (ORS) is possible. Though different protocols are followed in different institutions, a simple one is as follows:

Step I. Infuse 20 ml/kg of Ringer lactate or normal saline as bolus over 20 minutes to restore the intravascular volume, which may be repeated in cases of severe dehydration or shock. However, maximum rate of infusion should never exceed 30 ml/kg/hr to avoid volume overload. Potassium is usually withheld in this

Fever with petechial/purpuric lesions indicates serious life-threatening infections, often associated with bacteremia, sepsis and meningitis. Common causes of hemorrhagic fevers in Indian children, excluding co­existing bleeding disorders, are as follows:

[†††] Viral fevers

Dengue (DHS/DSS)

Other arboviruses: Chikungunya, West-Nile virus, Kyasanur Forest disease

Non-polio enteroviral infections

Hemorrhagic measles or chickenpox

Bacterial infections

- Meningococcemia,

- Others: Anthrax, DIC

Spirochetal infections:

- Leptospirosis

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