Intercostobrachial Neuralgia (Armpit Nerve Pain)
Intercostobrachial neuralgia is a rare but very bothersome nerve pain issue. This is a nerve pain issue in which nerves coming from the upper thoracic spine and going into your armpit upper inner arm, and upper chest wall are damaged and cause pain in this region. You can learn more about the intercostobrachial nerve anatomy on wikipedia by clicking here.
Intercostobrachial neuralgia is most common in people (mostly women) who have had breast surgery for cancer such as mastectomy. This is known as post mastectomy pain. It also happens after radiation therapy to the lungs and upper chest wall. Trauma to the ribs such as rib fractures can cause intercostobrachial neuralgia. People who have had thoracotomy surgery also develop it. This is known as postthoracotomy pain. I have had a handful of men present to me with this problem, so intercostobrachial neuralgia is not exclusive to women by any means.
Intercostobrachial neuralgia is occurs in 25-60% of patients surviving breast cancer surgery!
The unfortunate aspect of intercostobrachial neuralgia is that very few physicians are aware of it, and the pain it can cause. Thousands of people suffer annually from this pain after getting surgery or radiation therapy and their surgeons never tell them what is causing the pain. Frankly, I suspect many of the surgeons do not know this can cause a serious pain issue! Secondly, most surgeons do not enjoy dealing with chronic post operative pain, in particular neuropathic (nerve damage) pain. Neuropathic pain is rather difficult to treat appropriately.
The first important step is a proper diagnosis. If I see a patient with a history of the above medical issues, I will see if their pain fits the anatomic distribution of the intercostobrachial nerve. I test the function of the nerve by testing sharp sensation, testing vibration sensation, testing cold sensation, and testing light touch. If I find these sensations impaired or painful, my suspicion of intercostobrachial neuralgia is raised.
Next, I generally suggest a diagnostic and hopefully therapeutic block of the intercostobrachial nerves using a strong local anesthetic and steroid medication. Typically I will use x-ray or ultrasound guidance to see the 1st through 3rd thoracic nerves as they pass between the ribs. These three nerves collectively form the intercostobrachial nerve. I will then inject some strong numbing medicine and some anti-inflammatory medication onto these nerves. This is called an intercostal nerve block.
If, when I inject this medication mixture onto the nerves the patient’s pain goes away and they become completely numb to sensory testing in the typically painful area, I can confirm the diagnosis. The numbing medicine typically lasts 4-12 hours during which time the patient is usually very happy as this is often the first and only pain relief they have ever had for this issue.
Next, the numbing medicine wears off and the pain may return. We then wait a few days for the anti-inflammatory medication to take effect and produce longer term pain relief. I have had a handful of patients get 100% complete resolution of intercostobrachial neralgia after these injections. Many, however, get a few months of relief and then the procedure can be repeated as needed if the pain returns.
If I find that my patient gets excellent short term but poor long term relief from the intercostobrachial nerve block, we can consider a procedure called pulsed radiofrequency treatment of the nerve. You may read about it on wikipedia here. This treatment uses radiofrequency energy to deliver electromagnetic pulses to the injured nerves. It is safe and non-destructive. Through mechanisms we do not understand fully, this procedure can help restore normal function of the nerves. This is called neuromodulation in general terms.
If the above does not work, we can consider a pain reducing device called a spinal cord stimulator (SCS). This device is like a pacemaker for pain. A thin wire is placed alongside the spinal cord where the nerves forming the intercostobrachial nerve emerge from the spine, and a small electrical current is used to block the pain signals from reaching the brain. This is a surprisingly very safe device that is used for many types of intractable nerve pains, not just intercostobrachial neuralgia.
There are also medication options which help reduce nerve pain that can be used as well. Unfortunately by the time most patients with intercostobrachial neuralgia see me, they have tried most of them. However, one medication very few have tried is called Qutenza. This is a very interesting medication. It consists entirely of the concentrated extract of chili peppers. This extract is called capsaicin. Many people have tried this medication in an over the counter preparation of 0.025%. This can be helpful but is often too weak. Qutenza is 8% capsaicin! This is much stronger and sometimes will work where nothing else has.
Physical therapy is, unfortunately, generally ineffective for intercostobrachial neuralgia given the nerve is usually too damaged. Sometimes the nerve may be irritated by tight muscles or scar tissue, which physical therapy can address. If I think that PT will help, I always like to get it on board with my patient.
In summary, if you have had chest wall or breast surgery or chest wall radiation therapy and are suffering from burning, tingling pain coming from your upper thoracic spine, going into your armpit, upper inner arm, and upper chest wall, you may be experiencing intercostobrachial neuralgia. The good news is that there are treatment options available.