# Infectious Thyroiditis in Children: A Challenging Diagnosis and Management

## TL;DR

This paper discusses a rare case of infectious thyroiditis in a child caused by a fourth branchial arch fistula and highlights the importance of thorough diagnosis and surgical treatment.

## Contribution

The paper presents a rare pediatric case of infectious thyroiditis with a fourth branchial arch fistula and emphasizes the need for surgical intervention.

## Key findings

- Infectious thyroiditis in children can be caused by anatomical malformations like fourth branchial arch fistulas.
- Surgical resolution is necessary to prevent complications and ensure proper thyroid function.
- Thorough imaging is crucial for diagnosing the underlying cause of infectious thyroiditis.

## Abstract

Infectious thyroiditis is a rare condition, and it is more prevalent in children due to anatomical abnormalities. The main cause is the presence of a pyriform sinus fistula derived from the remnants of the third or fourth branchial arch. This article presents a case of a five-year-old boy with infectious thyroiditis complicated by a cervical abscess. Despite temporary improvement with oral antibiotics, the complaints recurred, and a new course of intravenous antibiotic therapy was necessary. A cervical ultrasound, MRI, and direct laryngoscopy were performed in order to diagnose an anatomical malformation. It was only during surgery that the existence of a fourth branchial arch fistula was observed, complicated by an infected prethyroidal cyst and proximity thyroiditis. After surgery, the patient was discharged and followed up in the pediatric endocrinology consultation, with particular attention to growth, intellectual development, thyroid function, and imaging. This case underscores the importance of thorough imaging of infectious thyroiditis to find out the underlying cause and its surgical resolution to prevent complications and ensure proper thyroid function.