A woman presents with chest pain and shoulder pain. On examination, she is found to have pericarditis with pericardial effusion. This shoulder pain is mediated by

The pain of pericarditis is mediated by the phrenic nerve. The somatic sensation from the pericardium is carried by the somatic afferent fibers of the phrenic nerve. The pericardial pain may be referred to the supraclavicular region of the shoulder or lateral neck area (dermatomes C3, C4 and C5. Ref: Gray&;s Anatomy for students 3rd edition Pgno: 183