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What you have is probably Scalene Myofascial Pain Syndrome. When scalene muscle is the cause of pain, the pain is referred to chest, inner lining of scapula (shoulder bone), shoulder, posterior and lateral sides of the arm right up to the thumb and index finger. When this muscle shortens, this can press on brachial plexus a(bundle of nerves and blood vessels in the armpit) and the subclavian artery and can compress or irritate these structures and cause symptoms such as abnormal sensation, cold extremity, claudication, and lymphedema (swelling of lymph channels) in the involved extremity. This is a major cause of TOS or thoracic outlet syndrome.
The other possibility is a boil or abscess with infection of the surrounding skin. This can also cause similar pain. It can also be pinched lower cervical or upper thoracic nerves. Costochondritis too is a possibility. A MRI of the affected area or a CT scan where the lump appears may help reach the diagnosis. TMJ with inflammation of sternocleidomastoid muscle is another possibility that should be considered and a dentist or ENT consulted. Take care!
Hi,Symptoms of pneumonia JIROVECI