This case is of interest in understanding the cause of hypocalcaemia that led to the presenting tetany.
First, we note that hypomagnesaemia with secondary hypocalcaemia is a rare condition, most often seen in children.1
Mild hypomagnesaemia induces a resistance to parathormone action, but severe hypomagnesaemia leads to reduced secretion of parathormone. We also note that severe hypermagnesaemia has an important effect on calcium homeostasis due to the suppression of parathormone secretion. In this case, hypomagnesaemia was due to reduced intestinal absorption and was exacerbated by major diarrhoea that occurred during the 3 weeks prior to hospitalisation.
Vitamin D is also important in calcium homeostasis. There are many conditions that can lead to reduced vitamin D2
and secondary hypocalcaemia (). In this case, we noted reduced intestinal absorption due to celiac disease. But its also important to keep in mind that hypovitaminosis D may also be due to a lack of exposure to sunshine3 4
; this was certainly the case with our patient, who, as a Muslim, always wore a veil outdoors. Finally, we point out that during breast feeding there is an increased vitamin D requirement.3 5
There are many conditions that could lead to hypocalcaemia (). There may be an increased loss of calcium, as in the case of pancreatitis or osteoblastic bone metastases; it can be the result of a reduction in intake, as in acquired hypoparathyroidism (acquired during surgery, radiotherapy or multiple endocrine neoplasia); or it may be secondary to high dose bisphosphonate treatment.
Celiac disease is most often diagnosed in young children. It is recognised in all ethnic groups with a worldwide prevalence of 1% to 2%.6
The classic symptoms are diarrhoea, anorexia, abdominal pain, weight loss and a failure to thrive. In adults, there are two modes of presentation7
: the classic mode, with diarrhoea, abdominal pain and weight loss; and the silent mode, with no symptoms and an atypical presentation (ie, ferriprive anaemia or reduced bone density). Celiac disease rarely presents with a crisis of tetany.8–10
In our case, the diarrhoea accompanying this tetany was suggestive of celiac disease.11
- Hypomagnesaemia and hypermagnesaemia can lead to hypocalcaemia. The calcium levels cannot be corrected until magnesium has reached a standard level.
- Women who wear veils are at risk for developing hypovitaminosis D.
- Tetany is a rare presenting symptom of celiac disease.
- The association of major diarrhoea and tetany is suggestive of celiac disease.