Differential Diagnosis for Sore Throat
- Single Most Likely Diagnosis
- Viral pharyngitis: This is the most likely diagnosis given the patient's recent exposure to a friend with strep, but the rapid strep test was negative. The onset of symptoms after exposure to someone with strep could suggest a viral etiology, especially since the patient has been on recent antibiotics and steroids, which might have altered her immune response or the bacterial flora in her throat.
- Other Likely Diagnoses
- Bacterial pharyngitis (streptococcal or non-streptococcal): Although the rapid strep test was negative, it's possible that the patient could still have strep throat, especially with the recent exposure. The pending PCR results will help confirm or rule out this diagnosis. Other bacteria could also be responsible.
- Tonsillitis (recurrent): Given the patient's history of recent antibiotics and steroids for tonsillitis, it's possible that she is experiencing another episode, potentially due to a different pathogen or incomplete resolution of the previous infection.
- Do Not Miss Diagnoses
- Epiglottitis: Although rare, epiglottitis is a life-threatening condition that requires immediate attention. It can present with sore throat, difficulty swallowing, and shortness of breath. The patient's recent use of steroids might mask some symptoms, making it crucial not to miss this diagnosis.
- Lemierre's syndrome: This is a rare but serious condition that can occur after a bacterial pharyngitis infection, leading to jugular vein thrombosis and septicemia. It's essential to consider this in patients with severe or recurrent pharyngitis.
- Infectious mononucleosis: Caused by Epstein-Barr virus, this condition can present with sore throat, fever, and lymphadenopathy. It's crucial to diagnose as it can lead to complications like splenic rupture if not properly managed.
- Rare Diagnoses
- Diphtheria: Although rare in developed countries due to vaccination, diphtheria can cause severe sore throat and should be considered in patients with significant exposure history or incomplete vaccination.
- Gonococcal pharyngitis: This is a rare cause of pharyngitis but should be considered in sexually active individuals, especially if they have a history of sexually transmitted infections.
- Tuberculous pharyngitis: This is a rare form of tuberculosis that affects the pharynx. It should be considered in patients with risk factors for tuberculosis or those who have been exposed to someone with TB.