Differential Diagnosis for 15-year-old Female Patient with Exertional Dyspnea and Midline Back Pain
Single Most Likely Diagnosis
- Anemia: Given the abnormal red blood cell count, anemia is a strong consideration. Anemia can cause exertional dyspnea due to a decrease in the amount of hemoglobin available to carry oxygen to tissues, including muscles. The midline back pain could be related to the anemia itself or to another underlying condition.
Other Likely Diagnoses
- Asthma: Although the pulmonary function test was normal, asthma can sometimes present with normal results between episodes. Exertional dyspnea is a common symptom of asthma.
- Deconditioning: A lack of physical fitness can lead to exertional dyspnea. This could be a contributing factor, especially if the patient has recently become less active.
- Scoliosis or Musculoskeletal Issues: Midline back pain in a teenager could be related to musculoskeletal issues, including scoliosis, which might also contribute to exertional dyspnea if the spinal curvature affects lung capacity.
Do Not Miss Diagnoses
- Pulmonary Embolism: Although less common in teenagers, pulmonary embolism is a life-threatening condition that must be considered, especially with exertional dyspnea. The normal chest X-ray and pulmonary function test do not rule out this diagnosis.
- Cardiac Conditions (e.g., Hypertrophic Cardiomyopathy): Despite the EKG showing only sinus arrhythmia, other cardiac conditions could be present. These conditions can cause exertional dyspnea and are critical to diagnose due to their potential for serious complications.
- Sickle Cell Disease: If the abnormal red blood cell count is indicative of sickle cell disease, this could explain both the dyspnea and the back pain, as sickle cell crises can cause both symptoms.
Rare Diagnoses
- Pneumothorax: A spontaneous pneumothorax could cause exertional dyspnea and might not always be visible on a chest X-ray, especially if it's small.
- Ehlers-Danlos Syndrome: This genetic disorder can lead to musculoskeletal issues, including back pain, and potentially affect lung function or lead to conditions that cause dyspnea.
- Mitral Valve Prolapse: Although often asymptomatic, mitral valve prolapse can sometimes cause exertional dyspnea and chest pain. It's less common but should be considered in a differential diagnosis for exertional symptoms.