GI scoping in mast cell patients

• Mast cell patients often need gastrointestinal scoping procedures to investigate the cause of dominant GI symptoms or see the full extent of GI organ inflammation, dysfunction or failure.

• GI scoping procedures for mast cell patients require thoughtful preparation due to the many triggers these procedures present. Overwhelmingly, GI scoping is performed safely in mast cell patients.

• An IV is placed before the start of the procedure. It is not unusual for mast cell patients to be “hard sticks”, meaning that it is hard to place an IV. There are several reasons that this happens.

• Mast cell disease causes significant third spacing, a phenomenon in which the fluid is the bloodstream falls out of the bloodstream and gets stuck in tissues. This means that mast cell patients may not have as much fluid in their bloodstream as they should, causing functional dehydration. Dehydration causes the blood vessels to be smaller and more tense.

• Mast cell inflammation is linked to hardening of blood vessels over time, making it harder to get an IV into the vessel.

• Many mast cell patients have connective tissue disorders like Ehler Danlos Syndrome. In these patients, their connective tissue may not properly hold the blood vessels in the right place, making it harder to get an IV into the vein.

• I have a weird observation to add to the “Reasons IV’s are difficult to place in mast cell patients” list. I have found that for the past fifteen years, anytime I had an IV removed, something weird happened. There was some kind of deposit at the IV site. It felt “sandy” and kind of “crunchy”. Whatever was there was solid as I was able to roll it up and down the blood vessel in my arm. I now refer to this as “mast cell deposition” for want of a better term. Once the deposit was gone, which would take weeks, I could no longer get an IV at that site or below it. They would try to place an IV in one of those spots and it hurt a lot and just wouldn’t work. It was bizarre. All of my doctors are stumped. I have two theories: local mast cells have a huge inflammatory response that attracts way more immune cells that normal; or,  that those little sandy bits are platelets all clumped together since mast cells release platelet activating factor. This is purely speculation. Does this happen to anyone else?

• If you are allergic to adhesives like Tegaderm, be aware at Tegaderm is what comes in IV kits to put over the IV once it is placed. If you react to Tegaderm, be sure to remind your nurse when placing the IV that you cannot use Tegaderm and will need another kind of dressing. 

Moist heat can help blood vessels to relax and become larger, making them easier to find and to place an IV there. What worked for me was running a facecloth under really hot water, wringing it out, and letting the facecloth sit on my arm for about ten minutes before attempting to draw blood.

Mast cells are involved in inflammation of the blood vessels. If the mast cells irritate the blood vessels enough, vasculitis can occur. This may be local (close to the site of the IV) or diffuse (more widespread and affection many blood vessels.) Mast cell patients may develop vasculitis from the IV.

GI scoping is performed with twilight sedation. Typically, IV medications are given to patients to help with the discomfort and anxiety associated with procedure. These medications including propofol, midazolam, and fentanyl. There are no particular concerns for the use of these medications in mast cell patient. (These are the meds I use when I get scoped.)

Mast cell patients should premedicate prior to GI scopes starting the day before the procedure. The general recommendation for premedication uses H1 and H2 antihistamines, leukotriene inhibitors, and corticosteroids. You can find this protocol here:
- Prednisone 50 mg orally (20mg for children under 12) 24 hours and 1-2 hours before procedure
- Diphenhydramine 25-50 mg orally (12.5 mg for children under twelve) OR hydroxyzine 25mg orally, 1 hour before procedure
- Ranitidine 150mg orally (20mg for children under 12) 1 hour before procedure
- Montelukast 10mg orally (5mg for children under 5) 1 hour prior to procedure

Premedication is given in addition to regular daily meds.

• A number of patients, including myself, find that using IV antihistamines and corticosteroids before the procedure works better for us. I personally find this to be the case for me. Patients should work with their care team to amend their individual premedication procedure if necessary. My premedication protocol is:
- Prednisone 50mg orally 24 hours before procedure
- Diphenhydramine 50mg IV 1 hour before procedure
- Famotidine 40mg IV 1 hour before procedure
- Solu-medrol 40mg IV 1 hour before procedure

• Patients should be aware that IV diphenhydramine (Benadryl) is sclerotic to blood vessels. This means that the use of IV Benadryl can irritate or damage blood vessels. If using the IV Benadryl in a regular peripheral IV, this could cause irritation of the blood vessels. Dilution of the medication and pushing it slowly through the IV can help to avoid this.

• I personally dilute IV Benadryl in saline (1mL of Benadryl to 9mL of normal saline) and push it through the port over five minutes. I then push the saline flush over five minutes. Last summer, I had a midline placed so that I could deaccess my port in the hopes the ulcer at my access site would heal. A midline is basically one step above a regular IV. They aren’t intended for long term use and they aren’t central lines. Medication pushed through it enters the body is a small vein. With central lines like ports, the medication enters the body into a very large vein that blood is moving through very quickly. I got a really nasty case of local vasculitis from pushing benadryl through the midline. I was diluting each dose 1mL of Benadryl to 50mL of saline and it still hurt. We had to pull the midline after only nine days and I had to go back to using my port. Patients should work with their care team to determine if dilution and slow pushing is necessary in their individual cases.

Touching the GI tract from the inside causes massive mast cell activation. This triggers huge degranulation of mast cells throughout the GI tract. The chemicals released can trigger the activation of mast cells in other parts of the body. The degranulation of mast cells in the GI tract also contributes to a condition called ileusPremedication helps to lessen the severity of activation and degranulation.

Patients should not have to discontinue mast cell medications prior to scoping. If patients are on NSAIDs to block prostaglandin production, like aspirin, the provider may request that this med be skipped on the day of the procedure. However, this is at the discretion of the provider and is a decision specific to each patient. (Author’s Note: Many thanks to MastAttack admin Pari who reminded me of an important note regarding meds and biopsies. A number of mast cell patients also have eosinophilic GI disease. When biopsying for EGID, use of steroids, which is part of the mast cell premed protocol, will skew the results. Mast cell patients who have EGID or who are suspected to have it should speak with their care team about whether or not they need to avoid steroids and for how long in advance of a scope.)

• Patients may find their symptoms are worse than baseline in the days following the procedure. Many people find that increasing antihistamines for a few days can help to mitigate these symptoms. For example, some people do a Benadryl taper. I used to do the same before I ended up taking Benadryl every day. It goes like this:

Day One: 50mg Benadryl ever 4 hours

-Day Two: 50mg Benadryl every 6 hours

-Day Three: 50mg Benadryl every 6 hours

-Day Four: 50mg Benadryl every 12 hours

-Day Five: 50mg Benadryl every 12 hours

Patients should discuss this with their care team to see if this is appropriate for them.

• For many patients, the hardest part of lower GI scoping is the bowel prep. Bowel preping is inherently mast cell activating. Everyone has mast cells in their GI tract. Mast cell patients often have more mast cells than usual in their GI tract. The bowel prep procedure increases GI motility, leading to mast cell activation. Patients should be aware that these increased symptoms, while unpleasant, are not generally dangerous. Patients should ask their care team whether or not they should discontinue the prep or go to the emergency department if certain severe symptoms occur.

• The standard prep for colonoscopies uses some version of polyethylene glycol, things like Miralax or Golytely. Like everything else, there is no way to predict whether or not a patient with react to it. There are alternative preparation protocols for people who can’t use polyethylene glycol. My prep plan is as follows:
 Two days before the scope: 1 bottle of magnesium sulfate, 600mg oral docusate sodium, consume clear fluids only
- One day before the scope: 1 bottle of magnesium sulfate, 600mg oral docusate sodium, consume clear fluids only
- The day of the scope: 2 saline enemas, the first one given two hours before leaving the house, the second one given one hour before leaving the house

• Biopsies should be taken during scopes. Mast cells can cause inflammation on the cellular level and the tissue may be inflamed despite looking normal during the scope.

• Biopsies should be tested using immunohistochemistry (IHC) for the markers CD117, CD2, and CD25. CD117 will show any mast cells present. CD2 and CD25 are markers that are found on the mast cells of many patients with systemic mastocytosis.

• Sometimes providers order the lab to look for mast cells using regular microscopy staining instead of IHC. Toluidine blue and Giemsa-Wright are both stains that can show mast cells. However, IHC is much more accurate than using these stains. Mast cells could be missed by using these stains instead of IHC.

There is not usually enough mast cell DNA in GI biopsies to accurately test for CKIT D816V mutation, a DNA mutation that is associated with mastocytosis.

• You can find additional information on how to test these biopsies here.

There is not a universal way to report the number of mast cells seen with microscope in a GI biopsy that has been put on a slide. One of the more common ways to do this is to count the mast cells in five different high powered microscopy fields (hpf) and then average the counts.

There was an excellent paper published in 2014 called “Perioperative Management of Patients with Mastocytosis.” It is free and publicly available. You can find it here. I encourage you to bring this paper with you to the appointment. The paper discusses all the triggers we experience from surgery and how to medicate patients properly for the procedure. Even though GI scoping is not the same as surgery, the vast majority of advice on surgery in mast cell patients also applies to scoping procedures.

For further reading, please visit the following posts:

Premedication and surgical concerns in mast cell patients

The MastAttack 107: The Layperson’s Guide to Understanding Mast Cell Diseases, Part 5

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