Differential Diagnosis for a 22-year-old with Headache, Sore Throat, and Fever
- Single most likely diagnosis:
- Viral pharyngitis: This is the most likely diagnosis given the symptoms of headache, sore throat, and fever, especially with a negative rapid strep test. The presence of tonsillar swelling and difficulty swallowing also supports this diagnosis, as viral infections can cause significant inflammation of the throat.
- Other Likely diagnoses:
- Infectious mononucleosis (mono): Caused by Epstein-Barr virus, mono can present with sore throat, fever, and tonsillar swelling, similar to the patient's symptoms. A negative rapid strep test does not rule out mono.
- Acute bacterial pharyngitis (despite negative rapid strep): Although the rapid strep test was negative, it is not 100% sensitive, and a throat culture could still be positive for Group A beta-hemolytic streptococcus.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed):
- Epiglottitis: This is a life-threatening condition that requires immediate attention. Although less common in adults, especially with the introduction of vaccines, it can still occur and presents with severe sore throat, difficulty swallowing, and sometimes fever.
- Peritonsillar abscess: A complication of tonsillitis, a peritonsillar abscess can cause severe throat pain, difficulty swallowing, and fever. It is a medical emergency that requires prompt drainage.
- Lemierre's syndrome: A rare but serious condition that follows a throat infection, characterized by sepsis and thrombophlebitis of the internal jugular vein. It presents with fever, sore throat, and neck pain.
- Rare diagnoses:
- Diphtheria: Although rare in developed countries due to vaccination, diphtheria can cause severe sore throat, fever, and a characteristic pseudomembrane on the tonsils.
- Gonococcal pharyngitis: Caused by Neisseria gonorrhoeae, this infection can present with sore throat and fever, especially in sexually active individuals.
- HIV acute retroviral syndrome: Can present with sore throat, fever, and other flu-like symptoms, and should be considered in individuals at risk for HIV exposure.