Most children who have hypoparathyroidism occurs in the first years of life, it has autoimmune nature. Some patients with acquired hypoparathyroidism were found antibodies to the extracellular domain of a calcium receptor.
The symptoms of hypoparathyroidism in children
Hypoparathyroidism may be asymptomatic or have all the signs of complete and chronic insufficiency of parathyroid glands. Light of their failure can be detected only by laboratory studies. Early symptoms include muscle pain and spasms, and then there are sensations of numbness, tingling, and rigidity of the muscles of the arms and legs. Sometimes there are symptoms Chvostek, trousseau, or spasms of the larynx, hands and feet. Interval in days, weeks and months sweep to cause convulsions with loss of consciousness or without it. Such attacks start with pain in the abdomen, followed by developing the tonic rigidity of the body with the crowding of the head and cyanosis, which are often confused with epileptic seizure. Cramps can be accompanied by headache, vomiting, increase of intracranial pressure and oedema of the optic disc nerve, i.e., the signs of a brain tumor.
In children with prolonged hypocalcemia teeth erupt late and are irregular in shape. Disturbed formation of dental enamel, resulting in teeth are too soft. The skin is dry and rough, and the nails of the hands and feet appear horizontal stripes. Concomitant candidiasis of skin, mucous membranes usually precede development of hypoparathyroidism in children, the infection most often affects the nails, mucous membranes shell mouth and corners of lips, at least — the skin.
A direct consequence of prolonged hypoparathyroidism in children — cataracts. Sometimes there are other lesions of the eye (e.g., keratoconjunctivitis), which are of an autoimmune nature. Hypoparathyroidism in children may also be accompanied by adrenal insufficiency, chronic lymphocytic thyroiditis, Addison's disease—Barmera, or total alopecia areata, hepatitis, and primary insufficiency of sex glands.
Without timely treatment, impaired physical and mental development become irreversible.
Recorded low level of calcium (5-7 mg%) and high content of phosphorus (7-12 mg%) in serum. The concentration of ionized calcium in the blood (approximately 45 % of the total concentrations and more accurately reflect the state of calcium metabolism) is also reduced. The activity of alkaline phosphatase of the blood is normal or reduced. Usually there is a low level of 1,25(0H)203, but some children with severe hypocalcemia it can grow. The content of magnesium is normal, but if hypocalcemia is to be determined. When immunometrics the determination of PTH detected by the low level. The introduction of synthetic fragment (1-34) of human PTH (teriparatide acetate) leads to increase the content of camp and phosphate in the urine. This allows to distinguish hypoparathyroidism from psevdogipoparatireoz. The appearance of highly sensitive methods for the determination of PTH did this diagnostic test is optional. Radiography of the bones sometimes detects increased density metafit, characteristic of poisoning by heavy metals, solid plastics or bone. When x-ray or CT scan of the skull find calcification of the basal ganglia. The EEG is a widespread slow activity. In the absence of irreversible brain damage or epilepsy wave activity returns to normal a few weeks after normalization of calcium level. When concomitant adrenal insufficiency calcium in blood serum can not be reduced, but the treatment of this failure is manifested hypocalcemia.
Treatment of hypoparathyroidism in children
Emergency measures when tetany in newborns include intravenous injection of 5-10 ml of 10% calcium gluconate at 0.5-1.0 ml/min under control heart rate. Additionally prescribe calcitriol. The initial dose is 0.25 mcg/day, supporting of 0.01-0.1 µg/kg/day (maximum 1-2 mg/day). Calcitriol rapidly disappears from the blood, and it should be administered in fractional, in two equal doses. The advantage of calcitriol in the hypoparathyroidism in children is the rapid manifestation of the effect (1-4 days) and the rapid disappearance of hypercalcemia when the drug is removed in case of overdose (calcium level begins to decline by 3-4-th day). Currently, there are solutions, calcitriol (1 mg/ml) for introducing the inside (firm Roche Pharmaceuticals).
Upon reaching normocalcaemia you can continue the treatment of hypoparathyroidism in children a ergocalciferol, because it is much cheaper than calcitriol. The usual dose for infants and young children — 0.1-0.5 mg/day. 1 mg of ergocalciferol (vitamin D2) has the biological activity of 40 000 ME. At a later age is required to enter the 1.25-2.5 mg once a day. Ergocalciferol acts slowly, and hypercalcemia after its cancellation in case of overdose persists much longer. Its main advantage is low cost.
You must enter the patient with hypoparathyroidism enough calcium. You can assign calcium supplements in the form of gluconate or glubionate (Neo-Calglucon) in an amount equivalent to 800 mg of elemental calcium per day, but this is rarely necessary. In the diet should limit foods with a high content of phosphorus (milk, eggs, cheese).
In the early stages of treatment of hypoparathyroidism in children should determine the level of calcium in the blood serum, to assess the need for the use of calcitriol or ergocalciferol. With the development of hypercalcemia, the treatment is stopped, resuming it after normalization of calcium level. If hypocalcemia persists for a long time, rely on the elimination of brain damage and teeth is not necessary. Pigmentation, decreased blood pressure or loss of body weight indicate primary adrenal insufficiency, which requires special treatment. In patients with autosomal dominant hypercalciuria gipocalziemicescoe in the treatment of drugs of vitamin D may develop nephrocalcinosis with impaired renal function.