Differential Diagnosis for a 75-year-old man with trismus, jaw stiffness, and difficulty swallowing

• Single most likely diagnosis
  • Clostridium tetani: This is the most likely diagnosis due to the presentation of trismus (lockjaw) and jaw stiffness, which are classic symptoms of tetanus infection. Tetanus toxin affects the nervous system, leading to muscle stiffness and spasms, which aligns with the patient's symptoms.
• Other Likely diagnoses
  • Clostridium botulinum: While botulism can cause difficulty swallowing, it typically presents with additional symptoms such as diplopia, ptosis, and weakness. However, it's still a possible diagnosis, especially if the patient has ingested contaminated food.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Stroke or other neurological emergencies: Although the patient's symptoms suggest a tetanus infection, it's crucial to rule out other life-threatening conditions, such as a stroke, that could present with similar symptoms.
  • Diphtheria: This bacterial infection can cause respiratory and neurological symptoms, including difficulty swallowing. While less common, it's essential to consider diphtheria as a potential diagnosis, especially if the patient has not been vaccinated.
• Rare diagnoses
  • Clostridium perfringens: This bacterium typically causes food poisoning or gas gangrene, and it's unlikely to cause the patient's specific symptoms. However, it's still a possible consideration, especially if the patient has a history of recent trauma or surgery.
  • Other rare conditions: Conditions like Eaton-Lambert syndrome, myasthenia gravis, or rabies could potentially cause similar symptoms, but they are much less likely and would require additional diagnostic testing to confirm.