Hi, I'm Dr. Amy Oxentenko. On behalf of two of my coauthors, Dr. Amrit Kamboj and Dr. Patrick Hoversten, I'd really love to spend a few minutes talking to you about an article that we recently published in the Mayo Clinic proceedings, and the paper was on chronic abdominal wall pain. Chronic abdominal wall pain is something that we see fairly frequently in our GI practice, moreso in the outpatient setting compared to in an inpatient setting. But chronic abdominal wall pain is something that we see in patients who've had chronic abdominal pain that seems elusive to any workup; they typically will undergo extensive workup with laboratory studies, radiographic studies, endoscopic evaluations. And then they're sent to us because no one can figure out what is the source of their abdominal pain.
So chronic abdominal wall pain is one of these diagnoses that you can make if you take a very careful history and target your physical examination. So chronic abdominal wall pain typically results from some entrapment of the cutaneous nerve of the abdominal wall. So this may result after an abdominal surgery where the nerves can be disrupted from surgical incisions. We can also see it as result of hormonal changes. And so patients will typically note that their abdominal pain is quite focal. Most the time — upwards of 40% of the time — it will be in the right upper quadrant, or it may be in an area of the surgical scar. And when you ask the patients to show you where the abdominal pain is, they can typically point with one or two fingers, particularly where their pain is most intense. They may also report certain activities that might worsen their pain, such as lying on the side where this abdominal pain is. Anything that pushes on their abdominal wall in that area may be irritating. Anything that stresses are tenses the abdominal wall can also cause them to have exacerbation of their pain. So those are important things to ask about in terms of the history.
Now, the examination is crucial to helping make this diagnosis. You're obviously going to do a full comprehensive history and examination. But one thing you can specifically do during the examination is called a Carnett sign. And so how you can evaluate a patient for a positive Carnett sign or the presence of a Carnett sign is to first have them lay supine on the table relaxing their abdominal wall. I usually first have a patient show me specifically where their pain is. And again, they often can point with one or two fingers, localizing their pain. So first I will palpate in that area of tenderness or pain that they have pointed out to me and ensure that I'm in the correct location. I'll typically keep my fingers right in that area of maximal tenderness while their abdominal muscles are relaxed, then I would I will have them do is either lift their head, off the bed, almost like an abdominal crunch. Or you can also have them raise their legs off the bed, whichever is easier for them, so that their abdominal wall muscles are tense. Typically in chronic abdominal wall pain, the patient will report worsening of their abdominal pain when you're tensing the abdominal musculature. Then what you'll have them do is relax the abdominal wall again and they're painful typically lesson if it's related to chronic abdominal wall pain. So again, a positive Carnett sign would be someone who has worsening of their abdominal tenderness in a focal area with tensing of their abdominal wall musculature and then improvement of their discomfort when they relax or abdominal wall musculature. So again, the history is critical. The examination really can help pinpoint this diagnosis.
When it comes to management then, the first thing is to reassure patients that this is something that is not going to lead to morbidity or mortality; it certainly can have a significant and impact on their quality of life. And that's what we're here to help improve and make their symptoms better. So first of all, reassurance is key. They can try over-the-counter or topical anesthetics, such as a pain patch, also known as a Lidoderm patch. These can now be obtained over the counter, which I think is very helpful. Some patients may find help with the heating pad or other abdominal binders to take some of that irritation off the abdominal wall. But most patients, when they've come to seek the attention of a medical specialists may benefit both diagnostically and therapeutically from a trigger point injection. So what a trigger point injection is, is a needle that is, and we use an anesthetic agent like a lidocaine derivative as well as a steroid, corticosteroid agent mixed together and again inserted into the area of maximal tenderness. This may or may not be done with ultrasound guidance to better localize the tip of the needle. And again, some patients will get immediate relief of this with the anesthetic agent, and then over subsequent days, we'll find additional relief as that corticosteroid takes effect. We know that some patients may need a repeat trigger point injection months or years down the line if their abdominal wall pain recurs, that many patients may have lasting benefit from this modality.
So I hope those are a few helpful tips to educate you about abdominal wall pain. Again, this is a common diagnosis that we see in the outpatient setting, especially for those patients who have really not come to an understanding of why they're having abdominal wall pain or abdominal pain despite an extensive evaluation. So this is something for both the patient and the clinician to keep in their back pocket as something to consider for those patients. Thank you.