Differential Diagnosis
- Single most likely diagnosis
- Pharyngeal diphtheria: The presence of a gray-dirty coating on the tonsils that is difficult to remove and bleeds upon removal is highly suggestive of a diphtheric membrane, which is characteristic of pharyngeal diphtheria. The acute onset of illness, high fever, and the epidemiological link to another case also support this diagnosis.
- Other Likely diagnoses
- Infectious mononucleosis: The symptoms of fever, sore throat, and enlarged lymph nodes could be consistent with infectious mononucleosis, especially in a young adult. However, the presence of a gray-dirty coating on the tonsils is not typical.
- Tularemia oropharyngeal form: Although less common, tularemia can present with pharyngitis and a history of exposure to infected animals or contaminated water. The symptoms and signs could fit, but the epidemiological history provided does not strongly support this diagnosis.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Pharyngeal diphtheria (also listed as the most likely diagnosis due to its severity and the need for prompt treatment): It's crucial not to miss this diagnosis due to its potential for severe complications and high mortality if not treated promptly with antitoxin and antibiotics.
- Rare diagnoses
- Yersiniosis respiratory form: This is a rare cause of pharyngitis and would be less likely without specific exposure history (e.g., to contaminated food or water).
- Tularemia oropharyngeal form (also listed under other likely diagnoses): While it's considered in the differential for its severity, it's relatively rare and would require specific exposure risks.
- Chronic tonsillitis: The acute presentation and specific findings (e.g., the gray-dirty coating) make chronic tonsillitis an unlikely diagnosis for this acute illness.