By Jennifer L. Gaudiani, MD, CEDS-S, FAED
As a reminder, the Gaudiani Clinic blog is medical information and not medical advice or professional consultation. The Gaudiani Clinic is unable to provide medical advice to individuals who are not our patients. If you have questions or concerns about your health, please reach out to your medical provider or schedule a consultation with our team.
Now that we’ve reviewed why mast cell activation syndrome (MCAS) matters for those with eating disorders in Blog One and how it’s diagnosed in Blog Two, let’s turn to treatment. This blog will review essential concepts in treating MCAS, while subsequent ones will focus on care of more specific populations like those who do not respond (or not adequately) to initial care protocols, those with postural orthostatic tachycardia syndrome (POTS), those median arcuate ligament syndrome (MALS) and superior mesenteric artery (SMA) syndrome, those with long Covid (LC), those with complicated digestive issues including small intestinal bacterial overgrowth (SIBO), etc.
Given how resistant medical providers can be to acknowledging MCAS, the really good news about treating MCAS is that many of the initial essentials can be started by non-prescribers, whether that’s an individual reading this, a family member, or a dietitian or therapist who has read the prior two blogs and wants to move ahead. Other good news is that the foundational treatments of MCAS aren’t generally harmful, meaning the potential benefit:risk ratio of just trying treatment is high. As these are started, obviously it’s best to search out a medical provider who has some MCAS expertise.
As with many other less-easily diagnosable but highly intrusive medical conditions that doctors aren’t presently very good at, those with MCAS have created a vibrant online community both via social media and blogs. Inevitably, some of these are better than others. For instance, there’s no requirement to disclose financial conflicts of interest where someone might get kickbacks for making certain recommendations. Plus, there’s a high risk for orthorexic themes in many of the resources out there, meaning that some recommendations could prompt a person to limit themselves excessively especially around food intake, triggering the eating disorder. Anything done in the name of “health” that triggers an eating disorder (to start, to persist) has to be understood as not healthy.
I have no financial conflicts of interest in any of this. When the Clinic recommends a treatment course, we never get any financial kickbacks. And I will always come to this from the perspective of recommending a least restrictive lifestyle across the board.
Let’s approach treatment of MCAS from three key perspectives:
· trigger avoidance
· medications
· nutritional considerations
This is what I go over with our imagined patient Melinda: I let her know that it’s pretty common for patients with MCAS to start treatment and, as they feel better, actually come to wonder if they ever had MCAS at all. This is in part because laboratory confirmation is difficult, and in part because those with EDs and MCAS (and trauma) may have a tendency to doubt their own lived experience/symptoms due to prior gaslighting. Also, it feels great to get used to feeling better! Often patients will stop their MCAS meds thinking they must be fine, only to remember, “Wow, I feel so bad off of these.” So I generate for Melinda a list of her baseline symptoms that we can review at each follow up. I tell her my patients often say with surprise as treatment is initiated, “Oh yeah, I guess that’s gone/better now!”
Melinda’s Symptom List
Alcohol intolerance (feels allergic, face gets hot, digestive distress, depression worsens)
Heat intolerance (skin turns red/gets hives, gets super sweaty, feels exhausted, gets edema, brain fog)
Edema (feet/hands/belly, not responsive to anything she’s tried)
Skin changes (lacy hives on chest, neck, and face worse with high emotion, random rashes, hyperreactive to bug bites, dermatographia, general itchiness even without rash, cystic acne)
Digestive distress after meals (burning/sharp pain, severe reflux, fullness/bloating, nausea, diarrhea alternating with constipation)
Artificial scents cause headaches
Drippy nose after eating, headaches, episodes of sinus infections
Feels allergic to her period (super heavy, cramps, terrible experience with the Pill, all physical and emotional symptoms worse during period)
Increasing medication allergies (rashes, throat feels tight)
Body pains/joint pains that migrate depending on the day
Easy bruising
Feeling flu-y after air travel
Reaction to brightly artificially dyed foods/drinks (gets a variety of above symptoms)
Dizziness and fast heart rate worse with standing, even when hydrated
TRIGGER AVOIDANCE
Consensus 2 doctors like me agree that when it comes to treating MCAS, the first through fifth most important treatment plan is trigger avoidance. This cannot be overemphasized. One of the huge challenges in MCAS is that triggers can change from week to week. Something that makes Melinda feel crummy the week of her period may be completely fine for her the week after. She may find that during highly stressful times (final exam time, work chaos, getting another illness like a cold or flu, a breakup, family conflict, worsening of her eating disorder), her mast cell reacts to more triggers than during times she’s well rested, nourished, hydrated, and feeling supported emotionally. It can also be bewildering how subtle a trigger can be and hard to tease apart what’s causing what because of course we are all exposed to countless different experiences in our day-to-day life.
All this to say that patients will need to be patient and show themselves and their treatment teams and loved ones grace as they start paying attention to what makes their MCAS react, and under what circumstances. However, there are some classics that almost everyone with MCAS will need to avoid, so let’s start with those. You might be someone who can clearly tolerate one of these triggers just fine, in which case listen to your body! Again, the goal is least restrictive living.
Classic MCAS Triggers
*Alcohol of any kind (including in skin products, makeup, topical and oral)
It’s absolutely astounding how common alcohols are in products we use daily. Hand sanitizer during Covid? Yep, it made many of my patients’ hands burn, get itchy, and develop rashes. They have to rely on washing instead with gentle soap and water and then using unscented/dye free lotion. Unexplained gum inflammation? So many of my patients are put on increasingly intense mouth washes that have either alcohol, dyes, or both, and this of course just sets their oral mast cells on fire and worsens the inflammation. Instead, they need to stop all those industrial-strength interventions and seek out extremely mild toothpaste (if this is even tolerated) and swish with one of the common mast cell meds named below, cromolyn.
On the positive side, with regards to our social relationship with alcohol, we happen to live in a time where “sober curious” individuals without a history of alcohol use disorder are choosing to live without alcohol, and where bars increasingly serve fun non-alcoholic cocktails. My patients feel so much better sober that they say they don’t miss the booze as much as they might have thought. And of course, if there’s a special occasion, and the patient knows how their body will react to alcohol, they have the right to choose to drink and get through the next couple days of reactions.
*Artificial dyes (FD&C red/yellow/blue)
This sounds orthorexic, but it’s real, and it can’t be skipped. Dyes are in everything these days, from food to drinks to detergent to skincare products to medications. Several of my patients have realized, “Oh, so this is why I get flushed and have a stomachache when I eat M&Ms, but I can eat a chocolate bar just fine.” There are also plenty of organic versions of candy that’s made with natural dyes that cause no problems. I’ve diagnosed a couple patients based on the simple observation they make, “I have this itchy armpit rash that won’t go away.” Ping! I stop everything and ask them about other MCAS symptoms. Almost always, it goes away with switching to a super hypo-allergenic/unscented/undyed deodorant.
It’s time to remove artificial dyes and scents from daily life…shampoos, lotions, soaps, home cleaners, detergents, supplements, drinks, and food. For the most part, I’ve found that the Vanicream line of skincare products does not trigger MCAS, although patients tell me their haircare products just aren’t nice to use. Time to put away the scented oils, candles, and air fresheners.
*Mold
Someone living with mold (in the walls, ceiling, bathroom) simply will never get better, no matter what triggers are avoided or medications are taken. Mold mitigation is challenging and may be expensive. Often you can find a local company to evaluate your home, or you can ask a landlord (with a doctor’s note) to perform this evaluation. A classic way of knowing whether something in your home environment like mold is keeping your MCAS in flare is to think about whether you feel significantly better when you leave for a vacation. Now, of course both rental properties and hotels can have triggering scents/triggers in them, but it’s a helpful rule of thumb. It’s possible you’d need to break a lease if mold cannot be mitigated, and a doctor’s note for medical necessity can help. If the air ducts haven’t been cleaned in a long time, it’s probably a good idea to do that if possible. Air filters may help, but mold particles can be so tiny that many filters will not grab them.
*Extreme heat/sun exposure
Since most patients with MCAS feel worse in the sun (some with very mild cases may not), it’s best to avoid everything super hot: hot tubs, long days outside in the sun, saunas, overly hot showers or baths, and even overheating when exercising. Staying cool and using ice packs or refreezable scarves or hats can be very helpful.
*Medications that are dyed or have other non-tolerated additives
This has been a huge eye-opener for me. Anything added to the active medication in a pill is called an excipient…fillers, colors, preservatives, etc., and patients with MCAS can be exceptionally reactive to excipients! The below-cited brilliant article is unbelievably helpful in detailing patient cases and validating how even the simple alteration in which generic medication is dispensed can cause a full-blown MCAS flare. If you write the clinic (info@gaudianiclinic.com), we’ll send you a PDF of this article as it’s behind a paywall. We can’t post it for copyright reasons, but we can send it to individuals!
Schofield JR, Afrin LB. Recognition and Management of Medication Excipient Reactivity in Patients With Mast Cell Activation Syndrome. Am J Med Sci. 2019 Jun;357(6):507-511. doi: 10.1016/j.amjms.2019.03.005. Epub 2019 Mar 22. PMID: 31126513.
Wherever possible, get the undyed/white version of a medication, although one of my mentors in the MCAS world pointed out that even white-appearing pills may contain dye. You may have to try getting medications compounded (with clarification in the prescription “dye free, sensitive fillers”) if you are one of the ultra-sensitive. If you’ve been doing pretty well, and a refill of a long-tolerated medication suddenly triggers symptoms, ask the pharmacist if you can go back to the prior manufacturer. Even in undyed medications, there can be fillers to which a patient reacts. For instance, in an ampule of cromolyn (see below) by a given manufacturer that has just cromolyn and water in it, a patient may react only to learn that another manufacturer’s cromolyn works fine. Why? We don’t know, although it could come down even to the microplastics present. Sometimes American patients have to source medications from Canada.
While it’s painstaking, you can go to this site with all your prescription bottles in front of you and look up every excipient using the NDC code on the bottle. Very often, patients with MCAS have not developed true allergies to medications, but rather they are reacting to the excipients therein.
*Eating disorders:
Remembering how stressful restricting, bingeing, and/or purging is to the body, and how stressful the ED voice is to the psyche, not surprisingly eating disorders are a major trigger of MCAS. Many of my patients have been able to reduce their extensive MCAS treatment regimen once they are recovered. Stress in general is a major trigger for MCAS, and patients often can trace back stressful events in their life as leading to a generally more reactive (“sicker”) chapter in their lives. Of course, patients cannot avoid stress altogether, but they can anticipate that when they are stressed, they will feel worse from MCAS. There are good “sick day” medication strategies below that can be employed to ease symptoms until the stress subsides.
MEDICATIONS
Once we’ve really covered trigger avoidance, understanding everyone will have their own individual triggers that will vary depending on how active their MCAS is at the time, we can turn to medications. Finding the right medication combination for those with MCAS can take a while, but patients can generally expect a meaningful improvement in symptoms over time as they learn what works for them. Patients with more than mild MCAS may end up needing a combination of 6+ over the counter and prescription medications, which can sound pretty overwhelming and indeed is. However, the benefit derived from getting MCAS under control is so wonderful that most patients are willing to keep managing the long med list. Many patients will need more medications at the start of MCAS treatment due to likely having been in flare for months/years/decades. As they combine trigger avoidance with a good medication regimen, though, they can often maintain on an easier regimen, while having a “sick day/week” management strategy for breakthrough symptoms.
Fundamentally, medications for MCAS aim for two outcomes:
· to keep mast cells stable (not degranulating)
· to block or ease the effects of mediators that are released
I will review medications in the order in which I usually start them. If a patient knows, suspects, or learns that they have an intolerance to any of these medications, of course they should not take them. Wherever possible, take medications that are undyed.
Histamine Blockers (over the counter)
Remember, MCAS is by no means solely a histamine problem, as mast cells can release over a thousand mediators that then trigger a cascade of inflammatory responses. However, histamine is a meaningful mediator, and we want ideally to block the effects of histamine once it’s released.
*H1 Blockers
These are non-sedating anti-allergy medications. In the US, examples include levocetirizine (Xyzal), cetirizine (Zyrtec), fexofenadine (Allegra), and loratadine (Claritin). The starting dose can be one tablet daily (these are very rarely sedating, so one might start at bedtime), increasing to twice daily (even when the bottle says 24 hour). If the patient doesn’t feel too dry—dry mouth, eyes, constipation—and this is a really helpful medication, three times a day is fine and even four tablets a day (2 in the am, 2 in the pm) can be very useful on sick days when MCAS is flaring. One might also take an H1 blocker at the time of boarding an airplane and another one just as descent is beginning, to reduce altitude and pressure-associated MCAS triggers that cause “travel flu.”
It is impossible to predict which H1 blocker will work best for a given MCAS patient. Ideally when financial resources allow, patients should cycle through the available H1 blockers every 2 weeks to find the one they just feel works best for them. In some cases, we’ve learned that using the Mark Cuban online pharmacy can really cut down on costs although higher than typical dosing for meds like H1 blockers may need several prescriptions sent each month.
Of note, diphenhydramine (Benadryl) is a sedating H1 blocker that crosses the blood-brain barrier. This can be very helpful for MCAS-induced insomnia or headaches (typically 12.5-50 mg nightly, starting with the lowest dose), for non-epileptic seizures (usually given intravenously), and for really reactive days. Interestingly, a dye free Benadryl capsule can be used per vagina at bedtime in those with severe period cramps/bleeding, and it melts and is absorbed right where it’s needed and can be very helpful. Benadryl’s constipating, sedating, and drying effect limit its daytime use.
*H2 Blockers
These are reflux medications that are a different class than the proton pump inhibitors (PPI) (omeprazole etc). In the US, examples include famotidine (Pepcid) and cimetidine (Tagamet), both of which can be obtained either over the counter or by prescription (compounded or regular). As with H1 blockers, a typical MCAS dose is always higher than the standard dose. I recommend a maximum dose of famotidine 40 mg twice daily (starting once daily, again to see if they tolerate the potential drying effects) or cimetidine 400 mg twice daily. Some patients express concern about early data that long-term H2 blocker use is associated with an increased risk of dementia later in life; the jury is out on whether it is the medication that causes it, or whether folks who need chronic H2 blockers are also independently more likely to have neurocognitive issues later on. Consensus 2 doctors suspect the latter. Patients already on a PPI can take an H2 blocker as well.
Prescription medications I add with or after H1/H2 blockers
*Cromolyn
Cromolyn (Gastrocrom in the US) is a mast cell stabilizer that I have found to be exceptionally helpful for my MCAS patients for systemic symptom management, specifically for digestive symptom management, and for skin manifestations. It comes in individual 5 ml ampules which contain 100 mg of liquid cromolyn, or one can prescribe it to a compounding pharmacy in 100-400 mg per capsule amounts. Since Covid inflammation triggers mast cells (more on this in a future blog), lots of cromolyn is being used in the US, and there have been shortages at compounding pharmacies that vary regionally.
Given that the H blockers can be constipating, I almost always start cromolyn as one of the 3-4 starting medications, because cromolyn tends to cause looser stools and can balance out the H blockers. It needs to be started slowly, 1 ampule by mouth twice daily for a week, then 1 ampule three times a day (ideally before a meal to reduce meal reactivity) for a week, then 1 ampule four times a day for a week. Then patients can increase slowly to the goal of 2-3 ampules before meals and at bedtime, four times a day. Some of my patients do end up on high dose cromolyn, like 4-5 ampules at each dosing interval.
When not taking compounded capsules, the little ampules can be emptied into an ounce or two of water, then swished for 30 seconds before swallowing. This can have amazingly healing effects on inflamed gums! In a pinch, the ampules can be taken directly without water, and I’m told they have a vaguely unappealing salty taste. Good insurance coverage is vital with cromolyn, as it’s otherwise exceptionally expensive. Without insurance but with a Goodrx coupon, a lowish dose of cromolyn can be obtained for around $150 a month. It can take over a month for cromolyn’s effects to be felt, so patience is needed. For the really med-reactive MCAS patient, titrating up even more slowly may be helpful.
In addition to its oral use, I love recommending that patients with a random rash or inflamed cyst on their skin rub an ampule of cromolyn on it. Oftentimes, poof! The rash disappears shortly thereafter. When this is needed longer term, cromolyn skin cream can be compounded. An ampule or two of cromolyn can also be applied to a tampon before insertion, and sometimes this can help with severe period cramps. Nasalcrom is a nasal spray cromolyn that can be tried for headache or brain fog as well.
* Montelukast
Montelukast (Singulair in the US) is a leukotriene inhibitor that’s commonly used in those with asthma. It has terrific efficacy in MCAS too. Started as a 10 mg once daily pill (compatible with other meds and taken any time of the day), it can really reduce reactivity to food and the environment. While every drug has its huge list of possible adverse effects, I’ve found montelukast to be really well tolerated…except for the 15-20% or so of my patients (higher than reported in the general population) who develop a major worsening in depression or even suicidality while on it. This goes away as soon as the medication is stopped, and any signs of these are indications to stop it immediately. If it’s tolerated, montelukast can be increased to 10 mg by mouth twice daily. If that serious mood alteration does occur on montelukast, its cousin zafirlukast can be used instead, 20 mg by mouth twice daily, 1 hour before a meal or 2 hours after. Because the dosing is burdensome, I always start with montelukast if I’ve gotten the patient’s consent to do so, given the above possible risk. Where dye sensitivity is a big deal, montelukast comes in a white dissolving granule packet.
Next tier medication strategies
*Herbal quercetin
Quercetin is an over the counter herbal mast cell stabilizer. I like Jarrow Quercetin 500 mg capsules, 2 capsules by mouth twice daily. They are naturally yellow, not dyed. They are a great 3rd option after H blockers for someone trying to manage MCAS while looking for a prescriber.
*Low dose naltrexone (LDN)
Naltrexone is an opioid antagonist that at typical prescription doses (50 mg a day) is used to reduce cravings in those with opioid or alcohol use disorder. However, interestingly at very low doses it has neuro-anti-inflammatory properties. Therefore, it’s much used in the fibromyalgia, Crohn’s, and chronic pain world. It’s also wonderful for MCAS and restless legs syndrome.
LDN is prescribed to a compounding pharmacy, optimally at 2 mg capsules once at bedtime for a week, then 4 mg at bedtime for a week. In month 2, one increases to the target dose of 4.5 mg nightly dose. It can be mildly activating at first, but this usually settles. Nausea, if present, typically swiftly resolves. A restless legs syndrome dose might be more like 2.5 mg nightly. Because pain is a quintessential symptom in MCAS, I use a lot of LDN. It’s also a great digestive healer and pro-motility drug. Given its mechanism of action, LDN must be stopped if any opioid pain medications are to be used, or if the patient is receiving ketamine.
*Ketotifen
Ketotifen is a prescription mast cell stabilizer, obtained through compounding pharmacy, that works differently than cromolyn and can be used alongside it. I used to ramp up doses fairly high with ketotifen, but I’ve learned that doses above 2 mg a day can cause fatigue. I therefore generally recommend starting at 1 mg by mouth nightly and if helpful, going to 2 mg at night or 1 mg twice daily. I’ve observed that this medication is particularly helpful for those with intense itchiness.
Over the counter ketotifen eye drops are also available. Given the reactivity to preservatives in those with MCAS, a preservative-free version is important to use. This can be very helpful for dry/itchy/allergic eyes.
*Benzodiazepines
Benzodiazepines are habit forming, anti-anxiety prescription medications. They must be used with great caution and under the direction of a capable prescriber. Low doses daily can stabilize MCAS, and in the setting of MCAS flares or non-epileptic seizures, intravenous or intramuscular dosing may be very helpful. Whenever possible, long-acting preparations are preferable to short-acting to reduce the high/low experience. They are also generally helpful for nausea.
*Omalizumab (Xolair)
Omalizumab is a monthly injectable approved in the US for those with more severe asthma as well as chronic idiopathic urticaria (CIU). CIU basically means “hives that appear without a clear trigger.” I would essentially say that anyone with MCAS who gets hives has CIU as one of their symptoms. Its mechanism of action is to bind IgE so that the IgE cannot bind to its receptor on mast cells and cause mediator release. Use of Xolair 150 mg subcutaneously monthly (usually given in an infusion center under nurse monitoring for the first three months to watch for allergic reaction, then can be arranged for home delivery and own use) can be a total game-changer in terms of patients’ reactivity. Some even need it every two weeks. The prescriber will have to name CIU as the diagnosis and document that hives continue to appear despite high dose H1 blocker use (and any other MCAS meds that are being used, despite which hives are still occurring).
*Seeking Health Histamine Block
This over-the-counter supplement, taken with meals, can be very helpful in reducing food reactivity.
There are so many other medications used for MCAS! But these are a good first start. I will discuss more digestion-specific MCAS meds in a subsequent blog.
NUTRITIONAL CONSIDERATIONS
This blog has gotten very long! I’m going to keep the nutritional considerations part short and summarized at this point. Essentially, someone with MCAS may react to a huge number of foods when they are in flare. This is not their “eating disorder talking,” and it will not simply get better with ED recovery, although ED recovery greatly reduces stress on the body and helps MCAS overall. Is it tricky for a dietitian to manage ED and MCAS together? Absolutely. It makes the already-complicated ED even more difficult for patients, families, and providers. However, having eating disorder RDs competent in managing both will help immeasurably!
Believe the patient…and seek the least restrictive diet
We must believe our patients when they say that certain foods make them feel bad. The rigidity and rule-boundness of the ED voice may make it hard for patients with EDs to understand that while last month, gluten hurt their stomach and made them react during a really stressful time, this month with less stress and better mast cell management, it’s fine. We can encourage patients to tune into their bodies (not always an easy task!) and really share with us what’s the ED fear and what’s the MCAS reaction. Overall, our goal is to help patients manage their MCAS and their ED until they have the capacity to eat in the least restrictive way possible. Often, there’s a pretty orthorexic contingent both among MCAS bloggers and treaters. By merging the ED and the MCAS worlds, I hope to help usher in a more flexible, body diversity-honoring, less diet-culture-y perspective to MCAS treatment.
“Low histamine” diets have little place in MCAS treatment
Remember that mast cells release or trigger over a thousand mediators, only one of which is histamine. While a very attuned GI/ED/MCAS dietitian may be able to guide a patient through a lower histamine diet, we have to realize that all foods can potentially trigger histamine and thus stay away from a super restrictive diet that threatens ED recovery. It’s tempting for someone with an ED and MCAS to read a blog and say, “Oh, so-and-so felt better when they stopped eating this food. I should too.” We once again need to direct our patients’ attention back to their own lived experience, to honor and respect it. If that food doesn’t cause them (this week) to react, they shouldn’t avoid it.
Patients with MCAS have legitimate but untestable food reactions
I have patients with EDs and MCAS who do not have celiac disease but absolutely get sick when they eat gluten. I even have patients with EDs and MCAS who need to eat a relatively lower carbohydrate diet in order to function well (although many of them have other complex digestive issues like SIBO/dysbiosis, which I’ll get to in a separate blog). The point is, as a field, we eating disorder providers have to stop reacting with such suspicion to patients’ stated food intolerances. Higher levels of care programs should stop requiring IgE testing for food allergies, because someone with MCAS will not have positive IgE testing (which shouldn’t be offered anyway…remember, what someone reacts to this week may be fine next week). We as providers have to show up less suspicious of patients; suspicion is shaming and unhelpful, not “rigorous.” Now, that doesn’t mean that caloric inadequacy is acceptable. Someone who presently has a lot of food reactions will need to tolerate higher portions of tolerated foods and/or the addition of elemental shakes that are neutral for their gut in order to meet their energy needs. But it does mean we have to become more sophisticated as providers in understanding that the patient’s lived experience is real and must be accommodated.
Leftovers may be triggering
Interesting, freshly cooked food from fresh sources will be more tolerable typically than leftovers. For instance, buying meat on a Sunday that is cooked on Wednesday and eaten as leftovers Thursday may yield MCAS reactions, while buying that same meat and cooking/eating it same day will not. Most MCAS patients learn to freeze fresh foods and thaw/cook/eat the same day. It’s a good tip that keeps food options broader.
I tell Melinda that I recognize that patients with MCAS and EDs can find themselves in a terrifying downward spiral, where MCAS reactions beget food intolerance and malnutrition (with or without weight loss), which is stressful and causes worse MCAS reactivity, etc. Getting out of this spiral involves identifying MCAS, avoiding triggers, starting on good medications and patiently figuring out which ones are best for her, and figuring out how to meet her nutritional needs consistently. One can, thankfully, swiftly find oneself on an upward spiral! We decide to start her on xyzal 5 mg daily (bumping up to twice daily if tolerated), pepcid 20 mg twice daily for starters, cromolyn as above, and montelukast 10 mg daily. She expresses some concern that if we start all of those at once, we won’t know what’s helping. I hold space for this and offer to start slower. The benefit to getting things managed from lots of different angles is that she feels better fast, starts to feel hope again, and her ED recovery is most protected.
For a terrific, in-depth book about MCAS, check out world-famous Dr. Lawrence Afrin’s book Never Bet Against Occam: Mast Cell Activation Disease and the Modern Epidemics of Chronic Illness and Medical Complexity (2016), available on Amazon.