Acute thyroiditis, also recognized as microbial inflammatory thyroiditis, is an uncommon inflammatory disease preceded by an infection, usually bacterial or less commonly fungal or parasitic, while the most common infectious agent is Staphylococcus aureus.
With the appearance and increased utilization of antibiotics, acute thyroiditis has become less common. Additionally, the disorder is rare due to the inherent resistance of the thyroid gland to infection. Nevertheless, it is most common in women aged 20-40 years old and most patients with the condition present with a pre-existing thyroid disorder such as a nodular goiter.
Common symptoms include anterior neck pain and tenderness, that radiates locally and may be worse with swallowing. Other symptoms include fever, pharyngitis, tachycardia and dermal erythema. Laboratory testing reveal leukocytosis and an elevated erythrocyte sedimentation rate (ESR) level while thyroid stimulating hormone (TSH), thyroxine (T4) and triiodothyronine (T3) remain normal.
Management of the condition is aimed at treating the root cause of the infection, identified by fine-needle aspiration, with appropriate antibiotics or medication. In some cases, patients may present with cold nodules and abscess formation which require surgical drainage and perhaps a thyroid lobectomy. The disease is usually self-limited but may last for weeks to months. For symptomatic relief, patients may rely on heat, rest and aspirin.
Written by Michelle Sveistrup, M.Sc., Director of Education and Publications, reviewed by Dr. Deric Morrison, Medical Advisor, MD FRCPC, Div. of Endocrinology, Dept. of Medicine, University of Western Ontario