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, and the radiation of pain from the right abdomen to the right shoulder, suggests a musculoskeletal origin. The fact that the pain starts in the right abdomen and then radiates to the right shoulder, especially with coughing, supports this diagnosis. The patient's reported separation of chest walls could also contribute to this condition.
• Other Likely Diagnoses
  • Pulmonary causes (e.g., pneumonia, pleurisy): Given the patient's recent diagnosis of bronchitis and continued coughing up of thick phlegm, it's possible that the pain is related to a pulmonary issue, especially if the infection has spread or led to complications like pleurisy.
  • Gastrointestinal causes (e.g., gallbladder disease, peptic ulcer disease): The location of the pain in the right abdomen could suggest a gastrointestinal origin, such as gallbladder disease or peptic ulcer disease, especially if the pain is related to eating or has other gastrointestinal symptoms.
• Do Not Miss Diagnoses
  • Pneumothorax: Although less likely given the patient's presentation, a pneumothorax could cause severe pain that radiates to the shoulder and is exacerbated by coughing. This is a potentially life-threatening condition that requires immediate medical attention.
  • Myocardial infarction: While the patient's symptoms do not strongly suggest cardiac involvement, myocardial infarction can sometimes present with atypical pain, including referred pain to the abdomen or shoulder. This diagnosis is critical to rule out, especially in patients with risk factors for cardiovascular disease.
• Rare Diagnoses
  • Hepatic causes (e.g., liver abscess, hepatitis): Although less common, hepatic causes could result in right abdominal pain radiating to the shoulder, especially if there is associated liver inflammation or infection.
  • Diaphragmatic irritation or rupture: This could be a rare complication of severe coughing or the reported separation of chest walls, leading to diaphragmatic dysfunction and pain radiating to the shoulder.