Primary hyperparathyroidism in children

Introduction to primary hyperparathyroidism in children Hyperparathyroidism (hyperparathyroidism) is caused by excessive synthesis and release of PTH, causing hypercalcemia and hypophosphatemia. Clinically divided into primary and secondary. Generally, the onset is slow, the symptoms are diverse, and the early stages are ignored. basic knowledge The proportion of illness: 0.002% Susceptible people: children Mode of infection: non-infectious Complications: constipation, coma, kidney stones, dehydration, fracture, headache

The cause of primary hyperparathyroidism in children

(1) Causes of the disease

Most of them are parathyroid adenomas, parathyroid hyperplasia and parathyroid carcinoma are rare. Some patients have a family history of familial parathyroidism, which is autosomal dominant, and can occur in adults, children and newborns. Mainly hyperplasia of the parathyroid gland, autosomal recessive inheritance, common in infants, can occur after birth, can die due to severe hypercalcemia, this type is parathyroid gland clear cell proliferation, such as mother long-term Low persistent hypocalcemia can cause temporary parathyroidism in newborns.

(two) pathogenesis

It is due to the proliferation of parathyroid tissue or the occurrence of tumors, resulting in increased secretion of PTH, the cause of which is still unclear.

Prevention of primary hyperparathyroidism in children

Primary hyperparathyroidism is caused by a single parathyroid adenoma (90%), less due to multiple adenomas or hyperplasia of the parathyroid glands, rarely due to adenocarcinoma, and some patients are Autosomal dominant inheritance, therefore, should pay attention to the prevention of genetic diseases, and for unexplained bone pain, pathological fractures, urinary calculi, hematuria, urinary tract infections, etc., should consider the disease, do the appropriate check as soon as possible Diagnosis, to give early reasonable treatment, such as early surgical removal of adenoma, or choose the right medication.

Primary complications of primary hyperparathyroidism in children Complications constipation coma kidney stone dehydration fracture headache

Can be complicated by intractable constipation, drink more urine, mental abnormalities, and even convulsions, coma, kidney stones, kidney calcification, joint calcification can limit activity. Osteolytic, osteoporosis, various bone deformities, such as "O" or "X" shaped legs, multiple spontaneous fractures can occur. When a parathyroid crisis occurs, headache, vomiting, convulsions, coma, heart block, renal failure, dehydration, electrolyte imbalance, heart and kidney failure, cerebral hemorrhage and infection occur.

Primary symptoms of hyperparathyroidism in children Common symptoms Polyuria constipation fatigue, abdominal distension, drinking, urinary calculi, bone pain, loss of appetite, convulsions, hematuria

1. Hypercalcemia group: loss of appetite, nausea, vomiting, bloating, intractable constipation, fatigue, weakness, muscle pain, polydipsia, abnormal mental disorders, such as emotional instability, personality changes, slow motion, lethargy, and even In shock, coma.

Such as calcification of internal organs can cause symptoms, such as kidney stones, kidney calcification. Joint calcification has joint pain, rigidity, and limited mobility. It is also seen that the ocular membrane is calcified.

2. Skeletal system: due to long-term PTH elevation of osteolysis, bone pain, can not stand, loose bones, various bone deformities, such as the spine, limb deformities, such as "O" or "X" shaped legs, Multiple spontaneous fractures occur in severe cases.

3. Parathyroid crisis: the incidence is mostly in childhood, there is also a disease in the first year of age, parathyroid crisis, when the blood calcium is as high as 3.85mmol / L (15mg / dl), headache, vomiting, and serious mental Symptoms, such as drowsiness, paralysis, coma, low blood pressure, unexplained high fever, heart block, kidney failure and other symptoms, if not treated in time due to dehydration, electrolyte imbalance, heart and kidney failure, cerebral hemorrhage and infection, and death .

Examination of primary hyperparathyroidism in children

1. Increased serum calcium: After repeated determination of blood calcium >2.5mmol / L (10mg / dl), the diagnosis can be confirmed, blood free calcium 1.28mmol / L (5.12mg / dl), the latter is more sensitive and accurate.

2. Serum phosphorus reduction: often 0.969mmol / L (3mg / dl), but normal or elevated in renal insufficiency, Ca / P ratio > 3.3.

3. Serum alkaline phosphatase: blood alkaline phosphatase can be normal when hyperplasia, adenoma increases, and is proportional to the severity of bone lesions, the more serious the bone lesions, the higher the enzyme value.

4. Determination of blood PTH: 80% to 90% of patients with elevated blood PTH, the degree of increase is consistent with blood calcium concentration, tumor size, and severity of disease, blood calcitonin is normal.

5. Urine examination: 24h urinary calcium excretion discharge>0.10.15mmol/kg (46mg/kg), 24h urinary phosphorus excretion>70% of phosphorus intake, urinary amino acid and cAMP excretion increased.

6. Calcium load PTH inhibition test: For suspicious cases, give calcium 4mg/kg per hour, intravenous infusion for 2h, regularly take blood to measure total calcium, free calcium and PTH, normal human blood iPTH (immunoreactive parathyroid hormone) Being suppressed, or even not detected, the patient's blood iPTH does not decrease or is slightly reduced.

7. The renal tubular absorbing rate (TRP) was lower than 84%, and the phosphorus clearance test (CP) was increased by more than 15%.

8. X-ray examination: the bone is extensively decalcified, osteoporosis, refers to the subperiosteal absorption of the phalanges, visible bone cyst formation and fracture, deformation, visible signs of active rickets in infants and young children, calcifications in the abdomen, such as kidney Stones, kidney calcification.

The skull showed a frosted glass or granules, and a few of the localized translucent areas disappeared.

9. Radionuclide scanning: mainly to detect parathyroid adenoma, and positioning.

Diagnosis and diagnosis of primary hyperparathyroidism in children

diagnosis

According to the clinical manifestations and laboratory tests, the auxiliary examination confirmed that hyperparathyroidism is easily overlooked in the clinic, but when there are unexplained bone pain, pathological fracture, urinary calculi, hematuria, urinary tract infection, intractable digestion In the case of ulcers, etc., the disease should be thought of and the corresponding examination should be done to confirm the diagnosis.

Differential diagnosis

1. Idiopathic hypercalcemia: often accompanied by congenital facial deformities and cardiovascular malformations.

2. Familial hypocalciuria and hypercalcemia: an autosomal dominant genetic disease with mild hypercalcemia but no clinical symptoms, mild hypercalcemia and low urinary calcium, serum iPTH decreased or normal, Endogenous or exogenous PTH caused an increase in renal cAMP, and the response was significantly higher than that in normal subjects and hyperparathyroidism.

3. Vitamin A, D poisoning: long-term use of vitamin A and D can cause hypercalcemia, the toxic dose varies with each person's sensitivity to drugs, generally considered to be 10 to 20 times higher than the physiological requirements of vitamin A can cause Poisoning, vitamin D dosage of 50,000 to 100,000 U per day can cause poisoning in a short time.

4. Malignant tumors: such as liver cancer, kidney cancer, lung cancer, etc. The liver tumor tissue contains ectopic parathyroid tissue, which can secrete parathyroid hormone and prostaglandins. It can also form high blood calcium when metastasis of malignant tumors. , neuroblastoma, lymphosarcoma, etc. can increase blood calcium.

5. Others: such as bed rest, post-burn and low alkaline phosphatase often have hypercalcemia.

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