Mast Cell Activation Syndrome MCAS

Finding Answers After Years of Mysterious Symptoms

After years of unexplained health issues, I finally found answers—Mast Cell Activation Syndrome (MCAS or M-CAS). Learn about my journey, symptoms, and how advocating for myself and research led to a diagnosis.

You may have wondered where I have been these last few weeks. My husband and I have been down with the flu for several weeks now. Our area has been inundated with covid and flu, and our local hospital is bursting at the seams. All is not lost, I have news to share.

Finding Answers: My Journey to a Mast Cell Activation Syndrome Diagnosis

Today, we’re taking a break from our usual DIY and home projects because I have some important news to share. For the past four years, I’ve been searching for answers to my health issues—puzzling symptoms, endless doctor visits, and a whole lot of frustration. But now, I finally have a working diagnosis: Mast Cell Activation Syndrome (MCAS).

Ever since I had the Covid vaccine, my health has taken turns I never saw coming. The symptoms seemed unrelated, doctors didn’t have answers, and I was left feeling stuck in limbo. But walking out of my recent doctor’s appointment, I felt something I hadn’t in years—relief. Relief in knowing my struggles had a name and that there was a path forward.

The Long Road to a Diagnosis

Getting to this point wasn’t easy. After countless visits and tests that led nowhere, I started researching on my own. I came across Dr. Robin Rose, whose research into Covid and the vaccine caught my attention. Through snippets of information she shared on the news, I began connecting dots that led me to Mast Cell Activation Syndrome. 

When I brought my research to a physician in the practice I had been seeing, he agreed it was worth exploring. We started with a simple treatment plan: work my way up to four Allegra per day over the course of four weeks, then introduce two Pepcid daily. Allegra is an H1 blocker antihistamine, and Pepcid is an H2 blocker antihistamine. Through my own reading, I have also found that Vitamin C is also a natural histamine blocker, so I have also picked up taking it daily as well. 

But simple doesn’t always mean easy. The first day I took Pepcid, I had one of the worst days I can remember. The pain was unbearable, and I started to doubt everything. Maybe I had been wrong. Maybe MCAS wasn’t the answer.

But the next morning, something incredible happened—I felt better than I had in years. My husband noticed it immediately, commenting that it was like I was a new person.

At my follow-up appointment, my doctor confirmed that my improvements strongly pointed to MCAS as the right diagnosis. While I never wanted another condition to manage, knowing what’s wrong gives me the power to move forward.

What is Mast Cell Activation Syndrome?

I had never heard of MCAS before my research, and if you haven’t either, here’s a quick overview. 

According to The Mast Cell Disease Society: 

"Mast cells release chemicals (called mediators) that can cause various symptoms, such as flushing, itching, hives, headaches, and digestive issues like diarrhea, nausea, and stomach pain. Low blood pressure can also be a symptom. To diagnose MCAS, a patient needs to show symptoms in two or more organ systems at the same time. These symptoms must happen repeatedly or be ongoing, and not be caused by any other condition."

Through my research, I’ve also found that MCAS symptoms can affect nearly every system in the body:

Other symptoms include:

• Skin: Flushing, itching, hives, swelling, and other skin issues like rosacea and/or warmness, red skin especially after eating 
• Gastrointestinal: Nausea, vomiting, diarrhea, abdominal pain, acid reflux, allergies to foods
• Respiratory: Wheezing, shortness of breath, congestion, chronic chest pressure or pain
• Cardiovascular: Low blood pressure, rapid heartbeat, dizziness, POTS
• Neurological: Brain fog, headaches, anxiety, sudden mood changes
• Other: Fatigue, temperature intolerance, anaphylaxis in severe cases, bladder related symptoms, bone pain, migratory pain that can move around the body, increased risk of osteoporosis, joint pain, tingling, chills, eye irritation, blocked nose

Common Triggers Include:

• Foods (e.g., high-histamine foods, alcohol, shellfish, chocolate, spicy foods, aged cheese, fermented foods, artificial sweeteners, food additives)
• Allergens 
• Temperature changes
• Stress
• Exercise 
• Heavy Metals
• Vibration 
• Infections
• Medications
• Strong scents or chemicals
• Smoke
• Mold
• Insect stings

The Role of Tryptase Level Testing

One of the key tests in diagnosing MCAS is a serum tryptase level test. Tryptase is an enzyme released by mast cells, and while elevated levels can indicate mast cell disorders, many MCAS patients have normal results. 

My doctor explained that while a high tryptase level can suggest systemic mastocytosis, MCAS is often diagnosed based on symptoms, response to treatment, and ruling out other conditions. In my case, my tryptase levels were within the normal range (I anticipated this, but I needed confirmation and I wanted a baseline on file), but my symptoms and reaction to medication confirmed the diagnosis.

My Personal Experience with MCAS

MCAS is unpredictable. Some triggers make sense, others don’t, and reactions aren’t always consistent. For example, one night my husband applied lotion to his hands—a lotion I’ve used for years without issue. But suddenly, my throat began closing off, and I struggled to breathe. Before I learned about MCAS, I had no explanation for this. I didn’t even bring it up with my doctor because, after past experiences, I felt like no one would listen or believe me.

Isn't it sad that once you have a negative experience with a physician, you are less likely to share things that happen in the future that are unexplained in your mind? 

Through my road to feeling better, I have found several answers to questions I have had over the last several years. Things I would not have figured out had I not stumbled upon Mast Cell Activation Syndrome, plus I am speaking up at my doctor appointments. Keep searching for answers if you find yourself in a similar situation, and do not let one person keep you from searching for more answers. 

I felt so defeated and often wondered why no one was finding anything wrong after so much testing over the years. It made me feel disconnected, angry at times, and other times I felt I would never figure out what was wrong with me.

I knew constant allergic reactions to medications was not something that was typical. I reported each and every one of the reactions, physicians shook their heads, and said nothing. Nothing. Nothing! I was beyond frustrated, and about to lose hope. 

I cannot tell you how much has changed since my follow up appointment, I am thankful. Thankful to have answers, thankful I am on a path to figuring out more. Although I wish there was a cure, I now know I just have to listen to my body and what it is telling me. Triggers can come out of nowhere. 

I am diligent in paying close attention to what I eat or products I come into contact with so I can store the information away. I need to take this a step further and create a journal of items I come into contact with on a daily basis, monitoring food, beauty products, scents and smells, etc. 

Prior to covid, I used a goat milk soap, now? I am allergic to all goat milk soaps. I have tried a few different brands, and have experienced reactions to all. This is all trial and error, and I imagine it will take me a while to figure out what my triggers are since they are ever-changing. 

There are times when I have a reaction to some of the most mundane things in life, and other times when those products do not bother me. Through research, I've read where exercising can increase histamines in the body which will cause triggers for a reactions. When histamine is increased in the body, more reactions will occur that may not be triggered on non-exercising days. Isn't the body a fickle thing? 

MCAS can be very serious, anaphylactic reactions to unknown triggers can make it very difficult to figure out what is causing the response. We know some triggers, but others do not make sense, and do not seem to be consistent for me. Since MCAS can also affect the body in other ways, it is sometimes difficult to pinpoint the triggers causing issues. 

Other Issues and Answers 

After being placed on Dupixent for severe asthma after covid, I developed painful, red bumps on my face. When I brought it up to my trusted nurse practitioner, she dismissed it, saying that Dupixent reactions only occurred at the injection site. I let it drop—until I saw my pulmonologist. Unlike the NP, he actually followed through. A few days after my appointment, he called me to confirm that yes, Dupixent can cause facial skin issues.

I saw a dermatologist, but the treatment prescribed only made things worse. We tried a facial foam and a specialty medication developed just for me. They both did zero treating my skin issues. In fact, they became more aggravated. I couldn't even cover it with makeup created for Rosacea redness.  

I felt embarrassed to be seen since makeup wouldn’t even cover the redness and bumps. Eventually, the doctor I have been seeing for MCAS confirmed that Dupixent was likely the cause. My skin, although it not back to normal, is improving. I do not feel as embarrassed now, I am hoping my skin goes back to normal. 

I went off Dupixent, cold turkey. Can I tell you that I was already feeling better after starting my regime of Allegra and Pepcid, but once the Dupixent was leaving my body, I began to feel even better?  My hoarse voice has improved, and I haven’t needed my rescue inhaler in weeks, Hallelujah! 

Before, I had been using my rescue inhaler several times a week while using Dupixent, something that it is supposed to eliminate. Well, I have been sick for nearly three weeks with the flu, and I have not used my rescue inhaler once. A respiratory flu would always require the rescue inhaler, sometimes multiple times a day because I would have such difficulty getting breath in. 

I believe MCAS was a contributing factor for my reactions to Dupixent. MCAS is some serious stuff, and really has created a lot of issues for me in being able to take medications that are supposed to heal. I now have an allergy sheet for medications I keep and add info as reactions occur. 

Advocating for Yourself & Raising Awareness

If there’s one thing I’ve learned through this process, it’s to never give up. I let a bad experience with a doctor discourage me for too long. But sometimes, hitting that bump in the road reignites our determination. The allergic reaction I had to antibiotics last year—and a doctor telling me she wasn’t sure how to treat me anymore—was my wake-up call. It pushed me to dig deeper by doing my own research and speak up to advocate for myself.

If you or someone you know has been struggling with similar issues—especially post-Covid or post-vaccine—know that you’re not alone. Keep pushing for answers, and don’t let anyone dismiss what you’re experiencing. You know your body better than anyone.

MCAS is more common than many realize, yet so few doctors are familiar with it. That’s why it’s important to spread awareness. If this story resonates with you or you know someone experiencing unexplained symptoms, please share this post. More awareness means more people getting the answers they need—and that can make all the difference.

For now, I’m taking things one step at a time, and continuing to read everything I can, but I finally feel like I’m on the right path. And that’s something worth celebrating. 🥳

Ciao,

Cara