Differential Diagnosis
- Single most likely diagnosis
- Infected thyroglossal duct cyst: The location of the pain and tenderness over the midline of the neck, in the region of the thyroid isthmus, along with the exacerbation of pain by swallowing or extending the neck, strongly suggests an infected thyroglossal duct cyst. This condition is a congenital anomaly that can become infected, presenting with symptoms similar to those described.
- Other Likely diagnoses
- Cat-scratch disease: Given the history of scratches from a cat, cat-scratch disease (caused by Bartonella henselae) is a plausible diagnosis. However, it typically presents with lymphadenopathy near the site of the scratch, which doesn't perfectly match the midline neck tenderness described.
- Tonsillitis: Although tonsillitis could cause neck pain and fever, the specific location of the tenderness over the thyroid isthmus and the exacerbation by neck movements are less typical for tonsillitis.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Retropharyngeal abscess: This is a serious condition that can present with neck pain, fever, and difficulty swallowing. Although the location of the tenderness is more suggestive of a thyroglossal duct cyst, retropharyngeal abscess is a potentially life-threatening condition that requires prompt diagnosis and treatment.
- Epiglottitis: Another potentially life-threatening condition, epiglottitis can cause severe throat pain, difficulty swallowing, and fever. The location of the pain and the presence of lymphadenopathy could potentially fit this diagnosis, making it crucial not to miss.
- Rare diagnoses
- Branchial cleft cyst: While a branchial cleft cyst could become infected and cause neck pain, the location is typically more lateral than the midline, making this a less likely diagnosis.
- Viral syndrome: A viral syndrome could cause fever and lymphadenopathy but would be less likely to cause localized tenderness over the thyroid isthmus. This diagnosis seems less specific to the symptoms described.