Differential Diagnosis for a 10-year-old Boy with Progressive Cough, Low-grade Fever, and Slight Dyspnea
- Single most likely diagnosis + C) Pneumonia due to Mycoplasma pneumoniae: This is the most likely diagnosis given the patient's age, symptoms (progressive cough, low-grade fever, slight dyspnea on exertion), and the radiographic findings (diffuse perihilar infiltrate). Mycoplasma pneumoniae is a common cause of community-acquired pneumonia in school-aged children, often presenting with these symptoms.
- Other Likely diagnoses + A) Pneumonia due to respiratory syncytial virus: Although more common in younger children, respiratory syncytial virus (RSV) can cause pneumonia in older children, especially during outbreaks. The symptoms and radiographic findings could fit, but the age makes it less likely than Mycoplasma. + B) Pneumonia due to Streptococcus pneumoniae: This bacterium is a common cause of pneumonia in children. However, the presentation is often more acute, with higher fever and more severe symptoms, which doesn't perfectly match this patient's profile.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.) + D) Congestive heart failure: Although less likely given the lack of specific cardiac symptoms or signs, congestive heart failure can present with similar respiratory symptoms and must be considered to avoid missing a potentially life-threatening condition. + E) Tuberculosis: While less common in previously healthy children in many parts of the world, tuberculosis (TB) is a critical diagnosis not to miss due to its implications for treatment and public health. The chronic nature of the symptoms and the radiographic findings could potentially fit TB, especially if the child has been exposed to someone with TB.
- Rare diagnoses + Other rare infections or conditions (e.g., fungal pneumonias, histoplasmosis, or cystic fibrosis exacerbation) could present similarly but are less likely given the information provided. These would be considered if initial diagnoses are ruled out or if there are additional specific clues in the history or examination.