Differential Diagnosis for Influenza-like Illness with Unexplained Tachycardia
- Single most likely diagnosis
- Influenza: The most common cause of influenza-like illness, which can present with tachycardia due to fever, dehydration, or the body's immune response.
- Other Likely diagnoses
- Respiratory Syncytial Virus (RSV) infection: Common in children and older adults, RSV can cause influenza-like symptoms and tachycardia.
- Adenovirus infection: Adenoviruses can cause a range of respiratory symptoms, including influenza-like illness, and may lead to tachycardia.
- Pneumonia: Bacterial or viral pneumonia can present with influenza-like symptoms and tachycardia due to infection and inflammation.
- Bronchitis: Acute bronchitis, often caused by viral infections, can lead to influenza-like symptoms and tachycardia.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Sepsis: A life-threatening condition that can present with influenza-like symptoms and tachycardia, requiring prompt recognition and treatment.
- Myocarditis: Inflammation of the heart muscle, which can be caused by viral infections, and may present with tachycardia and influenza-like symptoms.
- Pulmonary embolism: A blockage of an artery in the lungs, which can cause tachycardia and may be preceded by influenza-like symptoms.
- Meningitis: A severe infection of the meninges, which can present with influenza-like symptoms and tachycardia, especially in children and young adults.
- Rare diagnoses
- Hantavirus infection: A rare viral infection that can cause severe respiratory symptoms, including influenza-like illness and tachycardia.
- Lymphocytic choriomeningitis (LCMV) infection: A rare viral infection that can cause influenza-like symptoms and tachycardia, often in immunocompromised individuals.
- Tick-borne illnesses (e.g., Rocky Mountain spotted fever): Rare infections that can cause influenza-like symptoms and tachycardia, often with a history of tick exposure.