Sharp Right-Sided Armpit and Pec Pain Without Trauma
You must first rule out life-threatening cardiac, vascular, and pulmonary causes before attributing this pain to musculoskeletal origin, even in the absence of trauma. 1, 2
Immediate Life-Threatening Conditions to Exclude
Obtain a 12-lead ECG within 10 minutes to identify ST-segment elevation, new ischemic changes, Q waves, or T-wave inversions that would indicate acute coronary syndrome (ACS), as chest pain remains the predominant symptom in both men and women with cardiac events. 1, 2
Measure high-sensitivity cardiac troponin immediately, as women and younger patients frequently present with atypical symptoms including sharp, localized chest pain that can be mistaken for musculoskeletal causes. 1, 2
Assess for pulmonary embolism if you note acute dyspnea, tachycardia >100 bpm, tachypnea >20/min, or pleuritic quality to the pain, as 80% of PE patients present with dyspnea and 52% with pleuritic chest pain. 1
Evaluate for aortic dissection by checking for sudden "ripping" pain radiating to the back, pulse differentials between extremities, or blood pressure differences >20 mmHg between arms. 1
Obtain chest radiography to exclude pneumothorax, pleural effusion, or other pulmonary pathology, as these can present with sharp unilateral chest pain. 1
Most Likely Musculoskeletal Diagnoses (After Excluding Emergencies)
Pectoralis minor syndrome is the leading musculoskeletal cause of combined axillary and pectoral pain, resulting from compression of the brachial plexus nerves, axillary artery, and axillary vein under the pectoralis minor muscle. 3
Key diagnostic features include shoulder, neck, chest, and arm pain with paresthesia and weakness in the arm and hand, which can occur without any history of trauma. 3
Reproduce symptoms by applying digital pressure over the pectoralis minor muscle (just below the clavicle and lateral to the sternum) and performing provocative testing for thoracic outlet syndrome (Adson's test, Wright's test, Roos test). 3, 4
Arterial and venous Doppler ultrasound with dynamic investigation can display arterial and venous compression if neurovascular involvement is suspected. 3
Myofascial trigger points in the pectoralis major can cause sharp chest and arm pain with tingling in the forearm and hand, even without obvious trauma or overuse. 5
- Palpate the free border of pectoralis major (anterior axillary fold) for discrete tender points that reproduce the patient's pain pattern. 5
Costochondritis affects 42% of patients with nontraumatic musculoskeletal chest wall pain and is readily diagnosed by palpation of the costochondral junctions. 1
- Pain is typically stinging (53%) or pressing (35%), retrosternal (52%) or left-sided (69%), though right-sided presentation occurs. 1
Diagnostic Algorithm
Step 1: Immediate cardiac exclusion - ECG within 10 minutes, cardiac troponin as soon as possible, chest radiography. 1, 2
Step 2: If ECG shows STEMI or new ischemic changes, immediate transfer to emergency department for emergent cardiac catheterization. 2
Step 3: If ECG normal but troponin elevated, urgent cardiology consultation and transfer to emergency department. 2
Step 4: If both ECG and initial troponin normal, repeat troponin at 1-3 hours using high-sensitivity assay if intermediate cardiac risk factors present (age, hypertension, diabetes, smoking, family history). 2
Step 5: Once cardiac causes excluded, perform detailed musculoskeletal examination including palpation of pectoralis minor, pectoralis major, and costochondral junctions, plus thoracic outlet syndrome provocative maneuvers. 1, 3, 4
Step 6: If musculoskeletal origin confirmed, conservative treatment with NSAIDs (ibuprofen 400-600 mg TID if no contraindications), physical therapy focusing on pectoralis minor stretching and strengthening, and trigger point therapy is successful in most patients. 2, 3
Critical Pitfalls to Avoid
Never dismiss chest pain as musculoskeletal without obtaining ECG and troponin, as women, elderly, and diabetic patients frequently present with atypical symptoms including sharp, localized, or positional pain that mimics musculoskeletal causes. 1, 2
Do not use nitroglycerin response as a diagnostic criterion, as esophageal spasm and other non-cardiac conditions also respond to nitroglycerin. 1
Recognize that pectoralis minor syndrome can mimic cardiac symptoms, especially when symptoms occur with physical activity, as compression of neurovascular structures can cause chest pain and arm symptoms that appear cardiac in origin. 4
Consider pectoralis major rupture if there was any recent heavy lifting or bench-pressing activity (even if not recalled as "trauma"), as complete tendon rupture presents with sharp/stabbing pain and can have up to 5 cm of retraction. 6