Differential Diagnosis for Cough, Runny Nose, Sore Throat, Diarrhea, Vomiting with Fever

Single Most Likely Diagnosis

• Viral Gastroenteritis: This diagnosis is the most likely due to the combination of gastrointestinal symptoms (diarrhea, vomiting) and respiratory symptoms (cough, runny nose, sore throat) along with fever, which is commonly seen in viral infections such as norovirus or rotavirus.

Other Likely Diagnoses

• Influenza: Influenza can present with both respiratory (cough, runny nose, sore throat) and systemic symptoms (fever), and while less common, gastrointestinal symptoms can also occur, especially in children.
• Respiratory Syncytial Virus (RSV) Infection: RSV can cause a range of symptoms from mild upper respiratory tract symptoms to severe lower respiratory tract disease, and it's known to occasionally cause gastrointestinal symptoms, particularly in young children.
• Adenovirus Infection: Adenoviruses can cause a variety of clinical syndromes, including upper respiratory tract infections, gastroenteritis, and conjunctivitis, making them a plausible diagnosis for this constellation of symptoms.

Do Not Miss Diagnoses

• Pertussis (Whooping Cough): Although less common due to vaccination, pertussis can present with severe cough and can be associated with gastrointestinal symptoms due to the forceful coughing spells. It's crucial to consider this diagnosis to prevent outbreaks and to treat appropriately.
• Meningitis: While the primary symptoms don't directly suggest meningitis, in the early stages, especially in children, gastrointestinal symptoms can precede the more classic symptoms of meningitis (e.g., neck stiffness, severe headache). Missing this diagnosis could be catastrophic.
• Septicemia: Systemic infection leading to sepsis can present with a wide range of symptoms including fever, gastrointestinal symptoms, and respiratory symptoms. Early recognition is critical for effective management.

Rare Diagnoses

• Cytomegalovirus (CMV) Infection: CMV can cause a wide range of symptoms, including fever, sore throat, and gastrointestinal symptoms, particularly in immunocompromised individuals. It's less likely but should be considered in specific contexts.
• Myocarditis: Although primarily affecting the heart, myocarditis can present with systemic symptoms such as fever and might be accompanied by gastrointestinal or respiratory symptoms in some cases, making it a rare but potential diagnosis to consider.