Differential Diagnosis for Right Side Abdominal Pain Radiating to Right Back Side of Shoulder

• Single Most Likely Diagnosis
  • Musculoskeletal strain or costochondritis: The patient's history of severe coughing, which has been ongoing despite treatment for bronchitis, and the radiation of pain from the right abdomen to the right shoulder, suggests that the pain could be related to musculoskeletal strain, possibly from coughing. The fact that the patient was told he separated his chest walls (possibly referring to a costochondral separation or strain) supports this diagnosis.
• Other Likely Diagnoses
  • Pneumonia or lung abscess: Given the patient's history of bronchitis and continued symptoms of coughing up thick phlegm, it's possible that the patient has developed a complication such as pneumonia or a lung abscess, which could cause referred pain to the abdomen and shoulder.
  • Pulmonary embolism (less likely due to lack of specific risk factors mentioned): Although less likely without specific risk factors, pulmonary embolism can cause sudden onset of chest pain that radiates to the shoulder and can be associated with cough.
  • Gastroesophageal reflux disease (GERD): GERD can cause chest and abdominal pain that may radiate to the back or shoulder, especially if exacerbated by coughing.
• Do Not Miss Diagnoses
  • Myocardial infarction: Although the patient's symptoms seem more related to respiratory and musculoskeletal issues, myocardial infarction can present atypically, especially in younger patients or those with diabetes, and must be considered in the differential diagnosis of chest pain.
  • Pneumothorax: A spontaneous pneumothorax could cause sudden chest pain and could be precipitated by severe coughing. It's a critical diagnosis not to miss due to its potential for serious complications.
  • Diabetic ketoacidosis or other metabolic emergencies: If the patient has diabetes, the stress of an infection or other conditions could precipitate diabetic ketoacidosis, which can cause abdominal pain and other systemic symptoms.
• Rare Diagnoses
  • Pancreatitis: Although less likely given the description of the pain and the patient's history, pancreatitis can cause severe abdominal pain that radiates to the back and can be associated with cough if the patient has a pleural effusion or other pulmonary complication.
  • Cholecystitis or biliary colic: These conditions can cause right upper quadrant abdominal pain that may radiate to the right shoulder, but they would be less directly related to the patient's history of coughing and bronchitis unless the patient has a specific gallbladder disease history.