# Hypocalcemia Following Thyroidectomy in a Patient With COVID-19: A Case Report and Literature Review

## TL;DR

A woman who had thyroid surgery developed hypocalcemia during a COVID-19 infection, showing that the virus can cause this condition in post-thyroidectomy patients.

## Contribution

This case report highlights a novel association between post-thyroidectomy recovery and hypocalcemia triggered by a subsequent COVID-19 infection.

## Key findings

- The patient developed asymptomatic hypocalcemia 90 days post-thyroidectomy during a first COVID-19 infection.
- Severe tetany occurred 127 days post-surgery during a second SARS-CoV-2 infection, despite normal PTH levels.
- Treatment with calcium and vitamin D analogs resolved hypocalcemia and symptoms without long-term supplementation.

## Abstract

COVID-19 can lead to various complications, including severe respiratory symptoms. Both viral infections and total thyroidectomy are known to cause hypocalcemia, making a history of thyroidectomy a potential risk factor for hypocalcemia in COVID-19 patients. We present the case of a 34-year-old woman with Graves’ disease who developed hypocalcemia due to COVID-19 following a total thyroidectomy. The patient underwent an uneventful total thyroidectomy, with preservation of at least three of the four parathyroid glands. Postoperatively, her parathyroid hormone (PTH) levels were normal, and she was discharged without tetany. However, on postoperative day 90, she experienced mild hypocalcemia during a COVID-19 infection, although it was asymptomatic. By postoperative day 127, she presented with severe tetany and general malaise. Testing confirmed a reinfection with SARS-CoV-2 and hypocalcemia, while PTH levels remained normal. Treatment with intravenous calcium gluconate, oral calcium lactate, and alfacalcidol effectively resolved the hypocalcemia and tetany. The patient was subsequently discharged without tetany and has since been monitored without the need for calcium or vitamin D supplementation. This case highlights that the COVID-19 infection following a total thyroidectomy can cause hypocalcemia. Postoperative hypocalcemia is a common issue in head and neck surgery, and viral infections like COVID-19 should be considered in the differential diagnosis of hypocalcemia.