# Acute-Onset Type 1 Diabetes in a Patient With Autoimmune Polyendocrine Syndrome Type 3A Following Influenza A Infection: A Case Report

## TL;DR

A 63-year-old woman with Hashimoto’s disease developed type 1 diabetes after an influenza A infection, leading to a diagnosis of autoimmune polyendocrine syndrome type 3A.

## Contribution

This case highlights the rare but possible link between influenza A infection and acute-onset type 1 diabetes in patients with autoimmune thyroid disease.

## Key findings

- The patient developed diabetic ketoacidosis following an influenza A infection.
- She was diagnosed with autoimmune polyendocrine syndrome type 3A due to coexisting Hashimoto’s disease and type 1 diabetes.
- The case suggests clinicians should consider type 1 diabetes in patients with autoimmune thyroid disease after viral infections.

## Abstract

Type 1 diabetes is characterized by autoimmune destruction of pancreatic β-cells, driven by a combination of genetic susceptibility and environmental triggers. Influenza A virus infection has been reported to increase the risk of developing type 1 diabetes.

A 63-year-old Japanese woman with underlying Hashimoto’s disease contracted influenza one month prior. After contracting influenza A, she experienced persistent dry mouth and fatigue and presented to our outpatient clinic. She was diagnosed with diabetic ketoacidosis (DKA) caused by acute-onset type 1 diabetes. Given the coexistence of Hashimoto’s thyroiditis, she was diagnosed with autoimmune polyendocrine syndrome (APS) type 3A. DKA resolved with intravenous insulin and fluid therapy, and the patient was discharged on a basal-bolus insulin regimen. Clinicians should consider the possibility of type 1 diabetes in patients with autoimmune thyroid disease who develop hyperglycemic symptoms, such as polydipsia, polyuria, or weight loss, following influenza infection.