Kikuchi-Fujimoto disease co-occuring with Hashimoto thyroiditis: A case report and literature review

Area of Science:

• Internal Medicine
• Pediatrics
• Rheumatology

Background:

• Prolonged fever of unknown origin (FUO) with lymphadenopathy presents a diagnostic challenge.
• Kikuchi-Fujimoto disease (KFD) is a rare, self-limiting condition characterized by fever and lymphadenopathy.

Observation:

• A 16-year-old female presented with tender cervical lymphadenopathy, prolonged fever, and hypothyroidism.
• Exclusion of common FUO causes led to cervical lymph node biopsy, confirming KFD.
• The patient improved with non-steroidal anti-inflammatory drugs (NSAIDs).

Findings:

• Subsequent diagnosis of Hashimoto's thyroiditis was made due to elevated thyroperoxidase antibodies.
• This case highlights a potential association between KFD and autoimmune thyroid disease.

Implications:

• KFD should be considered in the differential diagnosis of FUO with lymphadenopathy, especially in younger patients.
• Vigilance for hypothyroidism is crucial during long-term follow-up of KFD patients.
• This association warrants further investigation into shared etiological or pathogenetic mechanisms.