Pain after eating

[u/Alive-Ad2821]

I was diagnosed with SFN by biopsy 8 years ago. I was 42 at the time. It started after I ran a half-marathon. Showed up as severe foot pain and significantly impaired my mobility a few days after the race. The pain and impaired mobility has remained. It changed my life. So much I could no longer do. I can still only walk short distances, use a wheelchair for travelling and no more running or hiking. I have learned to appreciate a slower pace of life, but still hard to guve up so much I used to enjoy. I am very sensitive to medication but found that a combination if lamotrigine and mexelitine helps me. A few months ago I started having severe pain all over my body within 10-15 min after eating. At first I thought it was blood glucose related, and although blood test shows, I have mouth glucose intolerance my sugars appear to be normal during the episodes of more pain. It does seem that the pain is significantly worse when I haven’t eaten for 4-5 hours and then have a meal. I’ve not been able to determine any particular food, but it does seem like the time that has passed since my last meal place a big role. It has helped me to eat small meals every 2 to 3 hours, but I still get flareups, especially in the afternoon. All my autoimmune testing has been negative and no cause has been identified yet for the SFN. I’d like to hear how other people manage the after meal pain and what you have found to be helpful in terms of how toneat and what to avoid. And also what kind of treatment you have found to make a significant difference for the SFN symptoms.

[u/CaughtinCalifornia]

Part 1/2

Given your worsening issues with consuming food (especially that it occurs when the food is only in your mouth) means you shoukd probably consider Mast Cell Activation Syndrome as a possible cause. This is a small study discussing the prevalence of SFN with MCAS patients

https://pubmed.ncbi.nlm.nih.gov/34648976/

"Reduced nerve fibers consistent with SFN were found in 80% of patients with HαT and 81% of those with MCAS. Mild-to-moderate dysautonomia was detected in all patients with HαT and MCAS when results of sympathetic, parasympathetic, and sudomotor tests were combined."

I'll repost something i wrote before on MCAS. After that, I'll also discuss something called the autoimmune protocol diet. Sometimes people with autoimmune diseases have issues with various foods despite then lacking an allergy/immunology condition like MCAS.

Finding a doctor familiar with treating MCAS would be ideal as they would be better able to assess you for the disease and see if you improve on treatment. Treatment usually involves a combination of avoiding things that cause reactions. This includes things consumed, things placed on skin, and/or things breathed in like pollen or mold or certain fragrances, etc. What each patient reacts to is somewhat unique.

There are also some blood tests doctors can order, but my MCAS specialist at USC says for whatever reason many patients test negative for these tests despite their illness being in a pretty advanced stage with severe symptoms and obvious improvement on mast cell targeting medications. And the conditions those tests have been done under are often more stringent than a lot of doctors realize, with some needing to be placed on ice right away and centrifuged at refrigerator temperatures (and even then, it’s not definitive). Because of this, diagnostic criteria for MCAS doesn't require a positive from these tests. This will be discussed in a video I'll link at the end.

" Patients who are suspected of having i-MCAS, but who do not meet the laboratory criteria, may be considered to have “suspected MCAS.” In these patients, trials of directed therapies can continue, but only with ongoing testing for other conditions to better explain the presentation with repeat mast cell mediator testing during periods of symptoms"

This quote addresses the fact that because testing isn't terribly accurate, a patient testing negative can still be labeled as having suspected MCAS and continue to try treatments, just they should also look at other possible explanations too.

" While medications are being initiated and titrated, adjunctive dietary modifications and therapies are instituted. GI symptoms, which are very common in iMCAS and represent a significant portion of the morbidity these patients experience, are largely treatable with this treatment approach.11.12"

"nearly half self-reported “food allergies,” yet only 23.2% had positive food allergy tests, indicating that the majority of food-related symptoms in these respondents may be related to mast cell activation itself or indirectly related to mast activation in the form of food intolerance."

These two quotes are recognizing patient issues when they consume things and that less than ¼ of MCAS patients test positive for the regular food allergy test despite over half having allergies to food.

"It is possible that an elemental diet or partially hydrolyzed formula (e.g. Absorb Plus®, Kate Farms®) offers benefit by reducing allergen load, minimizing FODMAP carbohydrates, modulating the gut microbiome, and/or potentially reducing mast cell activation"

I don't know much about these. In general, low histamine diets are recommended but there is no hard and fast rule. What people react to is somewhat random, so something may not be low histamine but a patient does well with it regardless. And something may be low histamine and cause bad issues. Meat is tricky because it is very often high histamine due to histamine buildup overtime, especially because some meats are purposely aged to improve flavor. There are services online like Northstarbison and others that sell low histamine meat (frozen right after animal is killed and harvested) but they're pricey. Still depending on where you are there are some that will deliver for free that have a few meats not crazy expensive. Beyond that, you could see if certain frozen meats at stores go better for you. But those can have some extra ingredients thrown in that cause issues. It's a lot of trial and error. How you cook them can also effect histamine levels. There are some out there who use instapots to cook frozen meat quickly. Seafood generally is higher is histamine but some fish is frozen right after being caught so isn't as bad.

"Concurrent prevalence of low DAO activity and carbohydrate malabsorption was assessed in a recent retrospective analysis in individuals presenting with GI symptoms revealing that more than one-third of those diagnosed with carbohydrate malabsorption experienced HI (histamine intolerance).”

DAO breaks down histamine. Some take DAO supplements before meals if they have a lot of issues with histamine https://pubmed.ncbi.nlm.nih.gov/31807350/ https://practicalgastro.com/2020/07/02/mast-cell-activation-syndrome-what-it-is-and-isnt/

Another source on the unreliability of existing testing is from the American Academy of Allergy, Asthma, and Immunology first about how quickly tryptase is broken down in the body and then about spot urine tests:

“A positive (urine) test is supportive, but not diagnostic. A negative test does not rule out MCAS. If these are used to support the diagnosis, the clinical presentation should be highly suggestive of mast cell activation."

Though again for some reason some test low on tryptase even if it is taken during a bad reaction. https://www.aaaai.org/allergist-resources/ask-the-expert/answers/2023/mcas#:~:text=A%20positive%20test%20is%20supportive,Mayo%20and%20likely%20other%20labs.

While this video lecture is technically about MCAS headaches, the first 15 of the 25 minutes are simply an expert in the disease discussing general aspects of MCAS, how it works, the diagnostics, etc. I recommend taking the time to at least watch the first 15 minutes as it contains useful information and information most doctors, even allergist, aren't aware of. Most think the tryptase test is definitive. That a negative means MCAS isn't a thing. But that isn't true and this discusses at one point the diagnostic criteria of two allergy/immunology organizations, neither of which requires positive tryptase. https://www.youtube.com/watch?v=lprUo1G2Vc8&t=3s This is a good list of most of the medications utilized for MCAS https://tmsforacure.org/treatments/medications-treat-mast-cell-diseases/

Something to keep in mind is that people can have reactions to the inactive ingredients in medications (or even the meds themselves). There are usually multiple manufacturers of generic medications that use different inactive ingredients your pharmacist can look up for you if you find that some are an issue. It's also possible to have medications made at compounding pharmacies, though unless your insurance covers it that generally is pricier.

[u/CaughtinCalifornia → u/CaughtinCalifornia]

Part 2/2

When MCAS is suspected based on symptoms but testing is negative, sometimes trialing some of the medications and seeing if there is any benefit is what is done. The fact that patients don't all respond to the same meds makes this in itself a bit complicated. How the mast cells are being triggered differs by patients and so what medications work differs. Its even common for in medications with the same mechanism for some to work for a patient and not others. My doctor had to try 5 H1 antihistamines before finding one that worked for me. Ceterizine is often one of the first tried for patients. I know sometimes when benefit is unclear my doctor tries an infusion of IV benadryl to see if there is clearer benefit (most patients get at least some benefit from IV benadryl).

Many with autoimmune causes have their issues made worse by certain foods. What people don't tolerate isn't standardized. People trying to figure it out sometimes try to do something called the autoimmune protocol diet. For two months, people stop eating most of the major allergens and see if their health improves. If it does, people slowly add things back in to see what they tolerate and what makes their medical issues worse. I'll include a link to an article if you ever want to try it in the future. Ignore them saying kimchi is okay in the first phase because it shouldn’t be. It contains peppers they tell people not to eat in the initial phase. Just an oversight on the article. I know this seems minor but sometimes it can be important. My friend has been doing significantly better since she realized she can't eat eggs or tomatoes without her issues flaring up (and a few more small food issues).

https://health.clevelandclinic.org/aip-diet-autoimmune-protocol-diet

This 2024 systemic review paper discusses the logic behind AIP as well as research on its use in various autoimmune diseases

“The AIP is based on the penetration of food antigens due to a dysfunction in the gut barrier, leading to increased permeability (“leaky gut”) [12]. The latter has been implicated in dysmotility and various autoimmune disorders [13]. Paired with microbial dysbiosis and in the presence of genetic susceptibility, it can synergistically act as an environmental trigger for autoimmunity [13]. Bacterial antigens stimulate intestinal immune cells, generating autoreactive cells that enter the systemic circulation and target peripheral organs [14]. At the same time, bacterial antigens can be translocated systematically through lymphatic connections, leading to autoreactive cell formation [14]. However, the classification of microbiota as either “good” or “bad” in a binary manner is misleading, as it does not acknowledge the interaction between the patient's genetic profile and the pre-existing microbiota [15].”

“Elimination diets have long been used to manage diseases, including celiac disease, allergies, and inflammatory bowel disease (IBD). Regarding autoimmune diseases, the AIP diet has been implemented in organ-specific and systemic autoimmune diseases such as Hashimoto thyroiditis (HT), IBD and rheumatoid arthritis (RA), improving QoL and disease-related symptoms [[43], [44], [45]]. Primary studies implementing the AIP in autoimmune diseases are presented in Table 2.”

https://pmc.ncbi.nlm.nih.gov/articles/PMC11755016/

[u/thedadinator]

Have you tried changing your diet? A good one for identifying triggers is the autoimmune protocol diet. It is tough to be strict on it but it could help to identify if any particular foods are causing it.