Is a rare condition characterized by hypocalcemia due to reduced production of parathormone.
- Primary (Congenital)
- Secondary (Acquired)
- Iatrogenic (Surgery)
- Autoimmune:
- Adrenal insufficiency
- Hashimoto’s
- Pernicious anemia
Causes
- Post-thyroid or parathyroid surgery (‘hungry bone syndrome’) or neck irradiation.
- Idiopathic (often autoimmune and presents in children or young adults).
- Congenital enzymatic deficiencies (numerous syndromes).
- Metal overload (e.g., iron (hemochromatosis or thalassemia), copper (Wilson’s disease), magnesium).
- Pseudohypoparathyroidism (reduced sensitivity to parathormone).
Clinical features:
-
Tetany—due to hypocalcemia; carpopedal spasm, fasciculation, and cramps Perioral paresthesia, Periorbital, fingertips cramps
-
Laryngismus stridulus—spasm of the vocal cord leading to dyspnea
Subclinical cases
-
Trousseau’s sign—flexion at Meta carpophalangeal joint and extension at interphalangeal joint on tying the tourniquet at the upper arm and raising the blood pressure above to 20 mmHg systolic pressure Prolonged QT interval on ECG.
-
Chvostek’s sign—on taping over the preauricular region, twitching of facial muscles
Diagnosis:
- Blood levels of ionized Calcium and PTH are low,
- Reduced serum calcium increases neuromuscular excitability.
- Also measure vitamin D and magnesium.
- ECG: shows a lengthened Q–T interval
Treatment:
Asymptomatic
- Calcium supplements PO
Symptomatic:
- IV Calcium supplement, you have to correct magnesium as well