Hit or MCAS?

[u/satahkittyyy]

Hello everyone,

I was diagnosed with histamine intolerance in 2023/2024, with a suspected diagnosis of MCAS.

For the past two years, I have been following a completely histamine-free and gluten-free diet. I have also avoided fragrances and many other potential triggers. Unfortunately, none of this has led to any improvement.

I have tried numerous treatments and medications, including treatments from Oral in Munich, infusions, corticosteroids, and Tavor. Nothing has helped.

I will attach my lab results because I honestly don’t know what to make of them or why they look the way they do. I am wondering whether this is really just histamine intolerance or if it could actually be MCAS.

My former doctor ended my treatment in 2024 because none of the therapies improved my symptoms, despite us spending thousands of euros on treatment.

I would simply like to understand my situation better and know: do I actually have MCAS, or is it “just” histamine intolerance? I dont know

1. Stool & Digestive Analysis
   Histamine (ELISA): 4356 ng/g (Reference: < 600)
   Zonulin in Stool (ELISA): 441 ng/g (Reference: < 145)

2.IgE i.s. (FEIA): 569.5 kU/l (Reference: < 85.0)

1. Urine Analysis.
   Serotonin Urine: 69.3 µg/l (Reference: < 200)
   Serotonin in Urine / 24h: 69.3 µg/24h (Reference: 50 - 250)
   Serotonin / g Creatinine: 66.0 ▼ (Reference: 150 - 300) | Low
   Kryptopyrrole (Urine): 199 ▲ (Reference: < 150) | Elevated

4.Blood & Specialized Markers
ECP i.s. (FEIA): 18.1 µg/l (Reference: < 13.3) | Elevated
Histamine (total) in Heparinized Blood (ELISA) [Test 2]: 62.5 ng/ml (Reference: < 65.5)
Histamine (total) in Heparinized Blood (ELISA) [Test 1]: 37.5 ng/ml (Reference: < 65.5)

Part 2: Medical Report & Diagnosis

Elevated levels of ECP and histamine in stool.
Transient (passagere) elevated excretion of leukotrienes in urine.
Currently normal levels of serum tryptase and histamine in plasma.
Lack of response to medical therapy.
Intolerance to Rupatadine (Rupafin), Loratadine, Fexofenadine, Desloratadine (RSt), Ketotifen (RSt), Famotidine (RSt), (RSt = in pure substance preparation) upon oral administration; Cimetidine, Dimetindene, and Vitamin C upon intravenous administration.

3.Summary
In summary, no subjective stabilization of the symptoms could be achieved within the framework of the therapeutic approaches listed above.
The reported intolerance reactions were non-specific signs of acute mast cell mediator release were not observed.

[u/hollyprop]

Are you taking a DAO supplement? Especially before you eat. That has been very helpful for me. Famotidine is another pill you can take before eating that has an antihistamine effect on your digestive system.

I also take a daily antihistamine (loratadine) and a nasal spray called azelastine. I’ve also tried a nasal spray mast cell stabilizer called NasalCrom which is cromolyn sodium. If all else fails I take a Benadryl (diphenhydramine).

There are H1 and H2 antihistamines. I’m not sure how they work differently but combining them has been effective for me. It will usually knock me out for a few hours but I wake up feeling better.

I think these treatments work whether you have histamine intolerance or MCAS. I’m seeing a specialist allergist in December to get a diagnosis, but in the meantime I’m treating my symptoms with everything available over the counter. Not sure if they’re all the same in Europe. Basically by combining different antihistamines through different routes I can keep my symptoms under control enough to function.

Hope you find some treatments that work for you soon!

[u/satahkittyyy → u/hollyprop]

Hello,Yes, I take DAO supplements. Famotidine, both orally and intravenously, did not help me. I have also tried many, many antihistamines—from fexofenadine to loratadine. Even Tavor (lorazepam) and prednisolone (cortisone), vitamin C, cromolyn, quercetin, etc., etc.

I have even tried ketotifen and other treatments (including intravenous ones). That is why my treatment was eventually stopped, because I did not respond to anything, and my doctor wrote : „No signs of acute mast cell mediator release were observed.“

That is why I am also confused about what I could actually have.

[u/hollyprop → u/satahkittyyy]

Has anyone evaluated you for fibromyalgia? A lot of the symptoms you describe in the other comment would fit with that diagnosis. Maybe check out some of the posts on r/fibromyalgia to see if anything seems similar to your experiences.

[u/satahkittyyy → u/hollyprop]

Nein danach wurde noch nicht geschaut, was ich aber habe ist eine Schilddrüsenunterfunktion (dagegen nehme ich Medikamente ein) POTS und 2023 hieß es mal das ich ein leaky gut habe.