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June 2017

The MastAttack 107: The Layperson’s Guide to Understanding Mast Cell Diseases, Part 29

37. What is the difference between mast cell activation syndrome, mast cell activation disorder, and mast cell activation disease?

Mast cell activation syndrome refers to a condition associated with very specific symptoms associated with mast cell mediator release. There are multiple sets of criteria for diagnosing mast cell activation syndrome so it is hard to be more specific than this. Generally, patients with MCAS have mast cell symptoms, evidence of mast cell activation seen in urine or blood tests, and response to medications that manage symptoms seen with mast cell activation. Several variations of mast cell activation syndrome now have ICD-10 codes, an important step towards becoming more accepted diagnoses.

Mast cell activation disorder is usually used interchangeably with mast cell activation syndrome. However, when pluralized as mast cell activation disorders, it sometimes refers broadly to any disease characterized by mast cell activation, like mast cell activation syndrome and systemic mastocytosis.

Mast cell activation disease is a broad term used for any disease characterized by mast cell activation, like mast cell activation syndrome and systemic mastocytosis.

Name your fear

Being chronically ill is an exercise in managing fear. There are so many of them and they all need attention in turn. You are afraid of the damage being done to your body. You are afraid of the damage being done to your mind. You are afraid of the damage being done to your relationships. And you are afraid of the damage being done to your life.

For me, none of these fears hold a candle to the one that looms largest in my mind: bloodstream infection.

Long before I learned about the intricacies of mast cell biology, I was an infectious diseases microbiologist. My first job out of grad school was developing rapid diagnostics for bloodstream infections. I spent thousands of hours studying pathogenic organisms like MRSA, VRE, E. coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Candida albicans and learning how to find them as fast as possible. I learned a lot about how often these infections occur and the sepsis they are and how fatal they are. (Pretty fatal, in case you’re wondering). The science around bloodstream infections feels very much like my old stomping ground if my old stomping ground was a burned out car in a Mad Max wasteland.

I have a central line permanently implanted in my chest for the purpose of giving myself IV medications and fluids daily. I had my port placed in September 2014. For several months before that, I had a PICC line in my arm to give IV access. Having a central line massively increases the risk of bloodstream infection. PICC lines are generally considered riskier than a port but ports are not a whole lot safer if it is accessed all the time like mine is. The likelihood of a line infection is not insignificant. It is on my mind every day.

In the 3 ½ years I have had a central line, I have never had an infection. There are basically two flavors of infections associated with lines: local site infections, where the place that the line crosses through your skin gets infected by organisms on the skin, and line infections, in which the inside of the IV line is contaminated. Both can be serious but site infections are less serious. In many instances, a site infection can be cured by pulling the line and putting in a new one somewhere else. Line infections are so dangerous because the bugs inside the line get pushed into your bloodstream and pass through your heart. Pulling the line often does nothing and most people end up in the ICU for several days or longer.

I am a maniac about my line. I exert a huge amount of effort to keep my site sterile and immaculate. I spend a lot of time sterilizing the end of the line before I inject any meds or hook up an infusion. I am extremely careful when I dilute medications to inject. I use a checklist when I access the line to avoid contaminating anything. If I think there is even a miniscule chance that I contaminated something, I throw it all out and start over again. But the most important way I protect against infections is by not letting anyone who isn’t me touch my line. My home care IV nurse is the only person aside from me that I trust to touch my line. I avoid going inpatient or to the ER at all costs because there are so many more people and the risk of contamination skyrockets.

Despite all of this, I work myself into a frenzy a few times a year in which I convince myself that I have a line or pocket infection. (A pocket infection is a kind of site infection you see with ports, which are implanted under the skin). Naturally, these frenzies occur when I am traveling because otherwise they would be no fun.

Deaccessing the port means taking out the needle so that I cannot inject medication into the port. The port is connected to my bloodstream. Without the needle, the port is pretty impervious to infection. Putting a needle back into the port is called accessing. It is a sterile procedure and involves sterilizing the skin and then putting a sterile dressing over the needle. Like many mast cell patients, I have very sensitive skin. I react to the betadine and alcohol I have to use to sterilize my skin. (I have tried other sterilization procedures, this one is the best for me because I react much more with others). I also react to the adhesive of the sterile dressing, although it’s much better than the alternatives. (I use IV3000 dressings and many mast cell patients have luck with them.)

I have to deaccess my port to go swimming. If I go swimming every day, this means that I have to take out the needle and pull of the dressing every day. When I need to use the line again later that day, I have to sterilize my skin and put on a new dressing. My skin reacts badly to doing this daily. I often get hives and it’s hard to clean off the adhesive residue left by the dressings without using a lot of alcohol, which I also react to.

When my skin reacts like this, it doesn’t look that different from a site infection. It is red and itchy. It sometimes hurts. I sometimes get hives. It can make it much harder to figure out what’s actually happening.

I’m in Mexico right now. There have been a lot of hiccups on this trip but it is insanely beautiful here. It is a special place. It is also incredibly hot here so I have been swimming a lot. I have been deaccessing for 4-6 hours at a time. Yesterday, as I will removing the needle so I could swim, a little bit of white fluid came out with a few drops of blood and the needle. It kind of looked like pus. I spent the next several minutes pushing on my port and trying to assess for signs of infection with thinly veiled panic.

Seeing pus come out with the needle usually means a pocket infection, an infection under the skin around the port. But if you access a port while having a pocket infection, it can push some of the infection into the bloodstream. As I am heavily dependent upon using the port for IV meds and infusions daily, it’s not safe for me to not have IV access. After trying to collect myself, I called my IV nursing team at home. We talked through some scenarios and the likelihood of infection.

After some deliberation, I went to the doctor on staff here at the resort. I was very nervous that he would be unable to help or not want the liability. He ended up being fantastic. He ordered the high dose oral antibiotics my home team requested. He works at a local private hospital and was able to arrange someone to start an IV for me daily if the port did end up being unusable. Alternately, I could go to the private hospital daily and they would give me my fluid infusions and IV meds through the IV they placed.

After some more discussion, my home team felt it was okay to try and access the port that night if there were no more signs of infection (especially not getting any white fluid out when pushing on the port). If I accessed it, I could use it normally. If there were signs of infection, I would keep it deaccessed and stop using it until I got home. Then I would have an IV placed and we would discuss IV antibiotics at the hospital.

Last night, after several hours of deaccess and worry, I was able to reaccess my port. It is working fine and has had no other signs of infection. I’m still not sure what the liquid was and it’s possible it was the start of an infection. It is also possible that the white liquid was from a burst hive, or a precipitate formed by the betadine on my skin reacting with the water here, or some stray sunblock that hadn’t gotten cleaned off. Just something to keep things lively.

There are a lot of obstacles in the path of anyone who travels with major health issues. The fear of needing help and not having it readily available is the biggest one for me. Understanding all the ways something can go wrong is so often a hindrance. It is much harder for me to just take things at face value and not worry about it.

So I don’t really know what happened and I’m probably never going to. This morning, I was just grateful to wake up with a working port in a coping body in this beautiful, special place.

The MastAttack 107: The Layperson’s Guide to Understanding Mast Cell Diseases, Part 28

36. Is MCAS less serious than SM?


There is a lot of literature presenting data on SM. There is a lot less on MCAS. This is largely because of how recently it has described and the fact that different sets of criteria make it impossible to do large scale studies as have been done with SM. So it’s hard to objectively compare the data because the same volume just doesn’t exist yet.

Many providers and researchers think of MCAS as a form of “preclinical SM”. This term was tossed around in the early 2000s by SM researchers who found patients that seemed to have SM but didn’t meet the criteria for it. There were a few presentations in which an image was shown of a line with the different types of SM shown.

From left to right, the line read:
Preclinical SM/Indolent SM/Smoldering SM/Aggressive SM/Mast cell leukemia

Based upon this figure, and the fact that we are trained to look at lines like this as continuum that either increases or decreases in order, many people latched onto “preclinical SM” (like MCAS) as being the least dangerous. Importantly, the figure refers to the increasing danger of permanent organ damage by mast cells ending up in organ tissues. It does NOT refer to the danger of anaphylaxis.

Indolent systemic mastocytosis (ISM) is the least dangerous form of SM and by far the most common. When people ask if MCAS is less dangerous than SM, they usually mean is MCAS less dangerous than ISM. A couple of small study groups have found that prevalence of anaphylaxis in MCAS is less frequent than in ISM. However, this comparison is flawed. Many people have known they have SM for 20+ years. MCAS hasn’t even been a viable diagnosis for 10 years. MCAS is also less likely to be diagnosed due to decreased exposure on the part of many providers. Many MCAS patients are diagnosed with idiopathic anaphylaxis instead so you’re not really looking at a robust population of MCAS patients in these studies.

ISM has a normal lifespan. It is treated the same way as MCAS and the two conditions have remarkably few differences beyond very specific markers that show the body making too many sloppy mast cells.

Some MCAS patients have protracted anaphylaxis and a normal baseline of very serious daily symptoms. It is my personal opinion that the anaphylaxis episodes I have observed in many MCAS patients can be a lot worse than you see in ISM. MCAS patients also have a harder time finding treatment. While ISM patients certainly run into unknowledgeable providers, it is my experience that having an ISM diagnosis is more helpful for facilitating treatment than an MCAS diagnosis.

We need time in order for larger studies and more unifying MCAS criteria to emerge but I am certain that these will follow. MCAS is at least as dangerous as ISM, if not more. Both MCAS and ISM are less dangerous than SSM, ASM and MCL.

For more detailed reading, please visit these posts:
The Provider Primer Series: Mast cell activation syndrome (MCAS)
The Provider Primer Series: Diagnosis and natural history of systemic mastocytosis (ISM, SSM, ASM)


I used to pride myself on traveling light. It was a skill I cultivated through years of hosteling and backpacking. I travelled with 2-3 changes of clothes, basic toiletries, one towel, a journal, a book or two, a phone charger, a flashlight, a first aid kit, and a wallet. It all fit into a green backpack. It is remarkable how thrifty you can get with your belongings when you have to carry them around, when you unpack and repack it all every day to move to a new city. Even when I was older and visiting friends or staying in a hotel, I never brought much. It was a hard habit to break.

When I was able to start traveling again in 2014, this phenomenon resurfaced into a new form. I packed light on clothes and toiletries because I needed so much space for the massive amount of medication and medical supplies I had to bring with me. When I went to China, I brought a nesting set of three suitcases, a shoulder bag, and the backpack that holds my IV fluids and infusion pump. I packed three changes of clothes, one pair of shoes, a journal, a flashlight, a toothbrush, shampoo and conditioner, an iPad, a plug adaptor, an electrical converter, and a charger. I couldn’t fit anything else with three weeks worth of supplies and meds. I actually had to buy some more clothes and toiletries when I got to Hong Kong.

Having that much luggage – and heavy luggage at that – stresses me out. I can’t pull all of it around without someone else helping me. I often can’t lift it. I’m always worried I’ll forget something and not notice until I’m there because it is so much to pack and there’s much stuff in there to see what I missed just by opening and looking. I have checklists but it still makes me apprehensive.

I’m not the only one who feels like I pack way too much stuff even if it is all necessary. Airlines think so, too.

I have written prolifically about the trouble I have when checking in at airports. Every time, they want me to do or have done something different. No amount of talking to disability services or ADA lines has helped because the airlines give a lot of authority to the supervisor there when you present. It played out mostly the same way it always does. I cried. What I will add is this new fun fact: if you are wondering how to get the supervisor to stop treating you like a piece of shit and help you, the answer is to start filming. Her demeanor changed so fast I almost got whiplash.

The airline argued with me for so long that I almost missed my flight. Getting through TSA was a nightmare and much worse than usual. There was no time to get anything to eat or drink and I was literally the last person boarded because of how long the airline held me up. But historically my travel woes mostly resolve once I’m on the plane and I was still headed to Mexico so things were looking up. Some kind passengers helped me with my luggage so I could get out appropriate meds and get settled.

I landed in Mexico and got through immigration and customs without any trouble. But when I found the company that was supposed to transfer me to my resort, they had no record of me. I was very glad to be able to speak Spanish at that point because it took a lot of back and forth. They ultimately found that I was booked for the wrong date but agreed to just take me anyway. Great. I got into the bus with my millions of pounds of luggage and we headed to the resort about 45 minutes away.

So then I arrived at the resort which had my reservation listed as starting four days later and things got really exciting. I had to shell out $1400 to even get into a room while it was being sorted out or they were literally going to turn me and my rare diseases and 17 suitcases full of IV bags away and we would have to walk home through the jungle where it is 400 degrees and even the trees sweat. It was over an hour before they even agreed that I could HAVE a room at all. To say I was alarmed is putting it gently.

I figured that once I got into a room, my travel agent and the hotel would be able to sort this all out and I would get a refund. That has not happened. After a very stressful back and forth with the travel agent, I asked her to stop texting me and just let me know when I would get my refund. I explained about my health and that this situation was just too stressful and to please just let me know when it was taken care of.

She didn’t stop and even though I didn’t read the texts, it was the final straw. My port was deaccessed so that I could go swimming so I had to give myself an IM injection of Benadryl and steroids at the pool. I went back to my room to access my port and hook up IV rescue meds and fluids. Fortunately, I did not have anaphylaxis. The meds worked and I bounced back. I told her to stop texting me and just email me about the refund when it is ready. I blocked her number and went to go sit on the beach.

It has been a long time since I have been able to travel alone. I’m not really alone here (I came for a wedding so some of my friends are here, too) but I’m alone in the sense that I don’t have anyone with me most of the time. In my mind, this trip is sort of a test run to see if I could maybe travel on my own again. If it goes well, I could maybe try a short trip somewhere else on my own. I love traveling alone. I miss it a lot.

In science, when we want to see how well things work, we do something called latitude testing, sort of testing worst case scenarios to try and “break” the system. This is how you learn how far the system can be pushed before it stops working right. This trip has levied a pretty good attempt at breaking my system. It has been stressful and frustrating. My body is reacting to that. But I have safeguards built into my system and they are working. I had rescue meds right there. I was able to respond quickly and keep myself safe. I was in control in the way that I needed to be. I was stressed but not scared.

All the reservations/money nonsense aside, this place is stunningly beautiful. It is warm and breezy and the night air is perfect for walking. The chefs have been super attentive to my food allergies and I haven’t had any trouble with food. My minibar is stocked with Mexican Coke and my safe potato chips.

Things will work themselves out. Or they won’t. I’m sure I’ll be fine.

The MastAttack 107: The Layperson’s Guide to Understand Mast Cell Diseases, Part 27

35. Why are there different sets of criteria for mast cell activation syndrome? What are the differences between them?

To answer this fully, we need to first discuss the history behind some terms.

Mast cell activation syndrome was first used to describe episodes of mast cell mediator release symptoms in a paper published in 2007 (Akin 2007). Specifically, the term was used to detail the experience of patients who had symptoms we commonly associated with mast cell activation, like flushing, hives, and low blood pressure.

However, the patients in this study were all found to have some features of systemic mastocytosis. While they had some of the criteria for an SM diagnosis, they didn’t meet all the criteria. These patients sort of looked like SM and quacked like SM but would not cleanly meet the diagnostic criteria. So the author of that paper made a separate diagnostic category for them. He called it monoclonal mast cell activation syndrome.

The use of the word “monoclonal” is VERY important here. Monoclonal is a medical term that is associated with the body making too many cells at once so that the cells that are made don’t work correctly. Systemic mastocytosis is a condition in which the body makes too many cells at once that don’t work right. It is a monoclonal disorder. So the author of that paper in 2007 is linking monoclonal mast cell activation syndrome to systemic mastocytosis. He thought of it as sort of a “pre-SM” or “early SM”.

Shortly after that 2007 paper was released, another school of thought was proposed by different groups about the nature of mast cell activation syndrome. These groups also linked the term mast cell activation syndrome to symptoms of mast cell activation, like flushing, hives, and all the rest. However, they did NOT link mast cell activation syndrome to monoclonality. This means that these researchers felt that mast cell activation syndrome could be present without a condition where you make too many sloppy cells like systemic mastocytosis. So patients with no evidence of systemic mastocytosis could still have mast cell activation syndrome according to these groups. The two major groups that believed MCAS was distinct from SM were led by Afrin/Molderings and Castells.

Let’s recap:

In 2007, Akin described mast cell activation syndrome as something that happened only in patients that had some evidence of systemic mastocytosis but not enough to be diagnosed with systemic mastocytosis. In order for this group to diagnose you with mast cell activation syndrome, you had to have evidence of systemic mastocytosis. It was an add on diagnosis to SM, sort of like SM with really bad symptoms.

In the years that followed, two groups, led by Afrin/Molderings and Castells, described mast cell activation syndrome as something that was distinct from systemic mastocytosis and could be found in anyone, even if they had no evidence of systemic mastocytosis at all.

Okay. So these two groups agreed that MCAS could happen to anyone. But they differ greatly in how they think MCAS can be diagnosed. For these groups, MCAS is NOT an add on diagnosis to systemic mastocytosis. It is a standalone diagnosis and entity.

So if the term MCAS was already being used, why didn’t the other groups just call their diagnosis something different? There isn’t a good answer to this but it is super common. Things are much more fluidly changing in the time between coining a term and having the diagnosis accepted by a large organization like the CDC so that your insurance can bill for treatment for that diagnosis. It would be great if everyone just used different names for their variants but this just doesn’t always happen.

Castells feels that in order to be diagnosed with MCAS, you have to show mast cell mediator symptoms, response to medications to treat mast cell activation, and evidence of mast cell activation. You also have to rule out every other possible cause of mast cell activation. Keep in mind that your mast cells are normally activated for lots of reasons so this can really difficult to do.

Additionally, this school considers mast cell activation to be evidenced only by elevation of serum tryptase, 24 hour urinary n-methylhistamine or 24 hour urinary prostaglandin D2 or 9a,11b-prostaglandin F2. So if none of these mediators are high, the patient doesn’t meet the criteria for diagnosis.

Afrin’s criteria are harder to explain because he believes that you should provisionally be diagnosed with mast cell activation disease, which can be a few different things, and then it should be narrowed down to mast cell activation syndrome or another mast cell condition.

The key difference between Afrin’s criteria and Castells’ are that he accepts elevated levels of several other mast cell chemicals to prove mast cell activation. Afrin counts toward diagnosis elevation of serum tryptase, 24 hour urinary n-methylhistamine, serum or 24 hour urinary prostaglandin D2 or 9a,11b-prostaglandin F2, 24 hour urinary leukotriene E4, heparin in blood, and chromogranin A in blood. All of these are released by mast cells. But some of them are released by other cells too so it’s not as easy to say for sure that mast cells cause the elevations. Additionally, some of these mediators are REALLY difficult to measure accurately, like heparin. So some people feel that these tests are less reliable to indicate mast cell activation alone.

Let’s talk about puppies for a second because when things get tough, just find a puppy and things will be cool from there on out.

Let’s present these three schools of thought on MCAS as puppies.

Let’s say that Akin is saying that all dogs with 10 spots on them have SM. He’s saying that dogs with some spots, but less than 10, have MCAS. He is also saying that dogs with NO spots CANNOT have MCAS.

Castells is saying that it doesn’t matter how many spots the dog has but it has to have either blue or green eyes to have MCAS. She doesn’t think the MCAS is related to spots but that it is related to specific eye color.

Afrin is saying that it doesn’t matter how many spots the dog has, or what color eyes. He will accept eyes of many other colors if the dog has a lot of symptoms that look like mast cell activation or respond to medications to treat mast cell activation.

I have simplified this as much as possible so it’s easier to understand. For that reason, I have omitted a lot of things. I am in no way saying that what I described here represents everyone’s experience. I am not saying that at all.

If you want my opinion on what MCAS is, and I’m inclined to think you do because you’re on my website reading my thoughts about mast cell disease, I feel that the evidence points strongly towards a space that blends both Afrin’s and Castells’ points. I feel that we should use more mast cell mediators than just serum tryptase, 24 hour urinary n-methylhistamine, serum or 24 hour urinary prostaglandin D2 or 9a,11b-prostaglandin F2. But I personally find the reliability of tests for heparin level to be very problematic and elevations of chromogranin A can be from so many things. I am not AT ALL saying that people diagnosed with these elevated markers do not have MCAS. I professionally develop diagnostics and these tests are just not great.

I also don’t think there’s enough evidence yet to say that mast cell disease can be proven with a biopsy demonstrating a certain number of mast cells per hpf (high powered field, this is a measurement we use for counting things we see under a microscope). I think it is very suggestive of inflammation and mast cell activity. But there are MANY instances in which normal, healthy, asymptomatic patients have a bunch of mast cells/hpf in their biopsies when they are used in studies.

So I’m solidly in the MCAS is its own entity group but don’t fall evenly into one group or the other regarding diagnosis.

Regarding treatment, I land more squarely with Afrin. I believe that if you have tried all of the conventional treatments and continue to have life threatening episodes, you should be able to try more drastic treatments provided you are well supervised by a knowledgeable provider. This is my personal opinion and in no way reflects the views of my employer. I think that if you are constantly anaphylaxing, or have no safe foods, or have dystonic seizures, or can’t stand up, and you have gone through a long list of “reasonable treatments” that you have a right to try to preserve your life and the quality thereof with any means available.

So, yea. MCAS is a can of worms. But we owe it to MCAS patients to have these awkward discussions even though it’s, well, awkward. Patients are falling through the cracks and we owe it to them to identify what criteria would let us catch them so they can get diagnosed and treated sooner.

I’ve tried hard to explain this objectively but if I haven’t done great, let me know in the comments.

For more detailed reading, please visit these posts:
The Provider Primer Series: Mast cell activation syndrome (MCAS)
MCAS: Differing criteria among experts

The MastAttack 107: The Layperson’s Guide to Understanding Mast Cell Diseases, Part 26

I answered the 107 questions I have been asked most in the last four years. No jargon. No terminology. Just answers.

34. What are the differences between the forms of systemic mastocytosis?

Indolent systemic mastocytosis

  • A form of SM in which the amount of mast cells produced in the bone marrow is excessive but not inherently dangerous to organ function.
  • Mast cells produced in the bone marrow are damaged.
  • These mast cells are released into the blood. While there are more mast cells than usual, there are not enough to overwhelm the blood.
  • There are fewer mast cells than in mast cell leukemia. There are often fewer mast cells than aggressive systemic mastocytosis or smoldering systemic mastocytosis.
  • The mast cells leave the blood and may enter organs inappropriately. Some patients do not have signs of too many mast cells being in an organ other than bone marrow.
  • The presence of mast cells in organ tissue can cause symptoms and medical signs but is not inherently dangerous to organ function.
  • It is not unusual for ISM patients to have typical mast cell symptoms and complications like anaphylaxis.
  • The lifespan for ISM is normal.
  • In indolent systemic mastocytosis, patients die from progressing to a more aggressive form of SM, such as MCL, ASM or SM-AHD.
  • Fatal anaphylaxis is always a risk with mast cell disease.

Smoldering systemic mastocytosis

  • A form of SM in which the amount of mast cells produced in the bone marrow is increasing to the point at which it might cause organ damage.
  • Mast cells produced in the bone marrow are damaged.
  • These mast cells are released into the blood. There are fewer mast cells than in mast cell leukemia. There are often fewer mast cells than aggressive systemic mastocytosis.
  • Mast cells leave the blood and enter organs in larger numbers than is normal. The presence of mast cells in these organs can cause symptoms and medical signs, like swelling of the liver.
  • Organ dysfunction can sometimes be corrected with surgery or certain medications.
  • It is not unusual for SSM patients to have typical mast cell symptoms and complications like anaphylaxis.
  • The lifespan for SSM is widely variable. One well known paper published survival of around ten years. However, many of the patients in this study were over 60 and age may have affected the average survival found in this group.
  • Patients with smoldering systemic mastocytosis are monitored to look for signs of significant organ dysfunction.
  • People with this diagnosis are considered to be possibly transitioning to a more serious form of systemic mastocytosis.
  • Smoldering systemic mastocytosis is the diagnosis that occurs between aggressive systemic mastocytosis and indolent systemic mastocytosis. It is thought of as the stage crossed when a patient with indolent systemic mastocytosis progresses to having aggressive systemic mastocytosis or mast cell leukemia.
  • In smoldering systemic mastocytosis, patients die from progressing to a more aggressive form of SM, such as MCL, ASM or SM-AHD.
  • Fatal anaphylaxis is always a risk with mast cell disease.

Aggressive systemic mastocytosis

  • A dangerous form of SM in which your bone marrow makes way too many damaged mast cells.
  • These mast cells are released into the blood. There are fewer mast cells than in the blood than in mast cell leukemia.
  • The mast cells leave the blood and go into various organs.
  • The presence and activation of the mast cells in the organs can affect organ function.
  • Over time, the presence and activation of mast cells in the organs can cause organ failure. This can sometimes be corrected with surgery or certain medications.
  • Typical mast cell mediator symptoms and complications like anaphylaxis are less common than in less serious types of SM.
  • The lifespan for ASM is much shorter than normal but is dependent upon response to treatment and which organs are involved. Older papers reference an average of 41 month survival but this has changed with more recent treatment options.
  • Generally, people with ASM live longer than those with MCL.
  • In aggressive systemic mastocytosis, patients die from the organ damage that has accrued over time by the presence and activation of mast cells in places they don’t belong.
  • Fatal anaphylaxis is always a risk with mast cell disease.

Mast cell leukemia

  • A very dangerous form of SM in which your bone marrow makes massive amounts of damaged mast cells.
  • These mast cells are released into the blood in overwhelming numbers.
  • The mast cells leave the blood and end up in various organs.
  • Specifically because of how many mast cells are present, mast cells invading the organs break up the organ tissue and cause severe organ damage.
  • The organ damage leads to organ failure, which leads to death.
  • Typical mast cell mediator symptoms and complications like anaphylaxis are less common than in less serious types of SM.
  • The lifespan for MCL is much shorter than normal.
  • Lifespan for MCL is usually quoted as being in the range of 6-18 months. However, there are more recent reports of some patients living 4+ years.
  • In mast cell leukemia, patients die from the organ damage caused by large amounts of mast cells entering and breaking up organ tissue.
  • Fatal anaphylaxis is always a risk with mast cell disease.
  • Of note, there is a newly described chronic form of mast cell leukemia. In this form, patients have stable mast cell disease despite having an overwhelming amount of mast cells in their bodies. The reason for this is unclear and long term survival is not yet known.

Systemic mastocytosis with associated hematologic disease

  • A form of SM in which the patient also has a separate blood disorder that produces too many cells of a different kind.
  • A patient with systemic mastocytosis with associated hematologic disease has too many mast cells and too many blood cells of a different kind. 
  • Previously called SM-AHNMD, systemic mastocytosis with associated clonal hematologic non mast cell lineage disease.
  • The two blood disorders, SM and the other disorder, are treated separately the same way they would be if the patient only had one or the other.
  • The lifespan for SM-AHD is wildly variable as it depends both on which type of SM the patient has as well as the type and severity of the other blood disorder.
  • An important thing to remember is if a patient has SM and another blood disorder that produces too many cells, they are classified as SM-AHD regardless of the type of SM they have. For example, if a patient who has ISM (normal lifespan) also has chronic myelogenous leukemia, they have SM-AHD. However, if the patient has ASM (shortened lifespan) and chronicle myelogenous leukemia, they still have SM-AHD even though the prognosis changes considerably.
  • In SM-AHD, patients die from having an aggressive form of SM, such as MCL or ASM, or as a result of their other blood disorder.
  • Fatal anaphylaxis is always a risk with mast cell disease.

For more detailed reading, please visit these posts:
The Provider Primer Series: Diagnosis and natural history of systemic mastocytosis (ISM, SSM, ASM)
The Provider Primer Series: Diagnosis and natural history of systemic mastocytosis (SM-AHD, MCL, MCS)


I started collecting postcards when I was 14. My uncle died abruptly that year and I took a road trip with some relatives to visit his son several states away in Georgia. When we were getting ready to leave, my parents told me to send them a postcard. I spent an inordinate amount of time looking for (and not finding) postcards in every rest stop and 24 hour gas station between here and Savannah. I finally found some at a visitor’s center near Roanoke, VA. An obsession was born.

I have thousands of postcards now. I get a bunch anytime I travel anywhere, even if it’s somewhere I have been before. Even if I’m only passing through a state or country. Even if it’s just a layover. If I find out someone is going to a country I don’t have a postcard from, I am not shy about asking if they will grab me a few.

There was a long time when I was too sick to travel. I lost a lot of things in those years. Travel was one of the hardest. Planning trips had always been an escape for me, even if I were planning trips I knew I would never take. I would read guidebooks and research flights and destinations and places to stay. I would often take out my postcard collection and flip through them, a palpable connection to this piece of myself that had been removed by force.

My health stabilized in later years but there are still many places I will never see, places that are just too far flung to chance with my need for accessible medical care. I have tried hard to make peace with that. Some days are easier than others. It is still something I struggle with, a loss that remains raw even after so long.

In 2014, I flew to Seattle with my best friend to visit one of my other best friends. It was sort of a rematch. My previous trip to Seattle had suddenly turned into a clusterfuck when I suffered GI failure 3000 miles from home. So in 2014, I took myself and my PICC line and two pieces of luggage stuffed with meds and medical supplies to Seattle. And I made it there, and I made it through the trip, and I made it home. For the first time in a long time, I started to feel in control. Not really in control of my life or my body, but in control of something. Something I wanted badly, that was an essential part of me. The ability to travel.

In the year after Seattle, I honed my traveling with masto skills with some domestic trips. I went to Colorado, Florida, and California. In November 2015, after months of planning, I flew around the world and spent two weeks in Hong Kong and mainland China. It was exhausting and complicated and very stressful. But it was also amazing in a way that few things in my life have been. When I am having a super shitty day, I think back to the way I felt when I landed in Hong Kong. Or when I first saw the Great Wall of China rising before me as it emerged from an otherworldly fog. Or when I crossed the threshold into the Forbidden City. Just pure gratitude for being able to be there in that moment. And awe that I was able to figure out how to work around the incredible complexity of international travel with the need for daily IV meds, IV fluids, and ready access to emergency medical care.

I used to be adventurous in the more traditional sense. I wanted real adventure: hiking in the Himalayas, long boat rides down remote rivers, cliff diving, camping in Patagonia, watching the Northern Lights from a sleeping bag under the endless sky in Iceland. I will never be able to safely orchestrate many of these real adventures. But in a way, the disappointment of this is tempered by the fact that I have unwittingly uncovered a different type of adventure: learning how to game my body and my disease to let me take these bites out of the world.

This is my adventure. Figuring out how to fold my life up into complex origami shapes and walking along the edges, planting a foot in the space governed by my disease, the other in the space of exhilaration and dreams. I will never know the triumph of summiting Mt. Kilimanjaro. But so many people will never know the triumph of making it to another continent, of spending years to see a place you dreamt about, of eating and working and waking the morning after a day you thought would kill you.

I do not enjoy the experience of having mast cell disease. I like things about my life but this is real life and not a symbolism-ridden novel. If I could snap my fingers and find myself occupying a healthy body, I would do it in a heartbeat. Being sick amplifies everything but that means every good thing is amplified, too. Every time I am able to figure out how to experience something or go somewhere safely, it is such a victory. It is infinitely more satisfying than if I never had to worry about my health. And I think that’s worth something.

I’m flying to Mexico in a few days for the wedding of a family friend. I have never been to Mexico. I started preparing for this trip six weeks ago, started packing two weeks ago, and now it’s almost here. I am currently having an obnoxious episode of “normal people sick” (as distinguished from “masto sick” – I have a nasty cold). A few years ago, I would have been panicked that I wouldn’t recover in time to safely travel. But after all the work I have put into this trip, it just seems silly that something like a bad sore throat and wet chest cough could get in my way. It will be fine. My doctors have cleared me and I’m not concerned.

In three days, I will be in Mexico. In nine days, I will have seen Mayan ruins, swam in the Gulf, and warched my friends get married on the beach. And in ten days, I will be home. With postcards.