192: Histamine Intolerance + Skin Rashes, PART 2

Brought to you by Quell

This episode is bought to you by Quell — to help support rebuilding healthy skin from the outside-in + inside-out!

Take 10% off your next order! Use promo code QUELL10 at check out — Get started HERE!

– – –

As I promised in PART 1 of the Histamine Intolerance series, it’s time to talk about the connection of histamine to estrogen.

Histamine and estrogen have a super messed up relationship that’s crucial to investigate in my clinical experience.

They can go hand-in-hand with one fueling the other and so on, making your symptoms increasingly worse over time.

Despite the deeper focus on estrogen, this episode is for both women AND men because both can end up victims of excess estrogen!

And I’m going to share about the two enzymes that play an important role for breaking down histamine.

Are you ready for this? Let’s dive in!!!

Or, listen on your favorite app: iTunes (Apple Podcasts) | Spotify | Stitcher | TuneIn | Subscribe on Android

In this episode:

  • Genetic issues associated with DAO + HMNT enzymes
  • Testing for SNPs that impact your histamine enzymes
  • Estrogen-histamine relationship — YIKES!
  • What part of your menstrual cycle might you be MORE reactive to allergens?


You have genes that code for two very important enzymes that dictate histamine breakdown — HMNT and DAO.

There is research suggesting that estrogen could increase the number of histamine receptors making you even more sensitive to histamine.

Portrait of frustrated young woman with headache and frowning while standing at home.

Histamine Intolerance + Skin Rashes, PART 2 (FULL TRANSCRIPT)

Welcome back to episode #192 of the Healthy Skin Show!

In today’s episode, I’m going to dive a bit deeper into the Histamine Overload issue that I started discussing back in episode #188. If you missed that episode, I highly encourage you to head back and listen to that first because it is the Part 1 to this conversation.

If you recall, I talked about how histamine overload looks a lot like a cup that’s contents are constantly near the brim so it doesn’t take much to cause the cup to overflow.

You could actually have a lot more going on than you even realize, but think that you’re “just an allergic person” or “it’s just genetic” when that may not fully be the case.

For example, if you find that you’re super reactive to foods higher in histamine, this could easily explain what’s going on under the surface. Normally, high histamine foods shouldn’t be a problem except when an overload picture exists or if you have an actual allergy to a specific food.

We often assume that histamine issues are pretty much an external problem. That’s why antihistamine medications are the go-to band aid.

But there often lies a complex internal mess that can absolutely play a role in histamine intolerance.

When you get to a point of frustration — whether medication isn’t really helping anymore or you’re becoming increasingly more reactive — it’s time to take a look under the hood.

That’s where histamine breakdown, genetics and hormones all can play a role together to facilitate a histamine overload picture.

If this is new to you, don’t worry!

I’m going to help you understand the basics so that you can start asking better questions and digging into your case to discover answers.

Filling up your histamine cup

Histamine Breakdown + Your Genes

As I shared in Part 1, genetics can play a role in how well you can tolerate histamine.

Not every case of histamine overload means there are genetic SNP issues at play, but it can’t be immediately ruled out.

You have genes that code for two very important enzymes that dictate histamine breakdown — HMNT and DAO.

I’ve already discussed that DAO (or diamine oxidase) is an enzyme found in your gut that breaks down histamines therein. Remember, inside your gut is actually outside of your body (that will be important in a moment).

HMNT (also known as Histamine N-methyltransferase) is another enzyme found inside of your body that is also responsible for breaking down histamine. This is a more system-wide enzyme compared to DAO.

As with all genes, it’s possible to have a SNP in one or both of these that could impact your body’s ability to breakdown histamine.

Should you have a SNP in one of the genes that codes for DAO or HMNT, it could mean that the impacted enzyme doesn’t function as well as it should and unfortunately can’t tackle histamine efficiently.

You can understand why it’s important to have properly functioning enzymes, but I’m sure you will wonder if getting tested for a SNP would be helpful in your case.

Well, to investigate a genetic impact on these enzymes pretty much means doing genetic testing. Your doctor may be able to help you with that.

There is some information on genetic SNPs impacting DAO and HMNT that you can pull from genetics reports such as 23&Me. (This page can help point you to some of the data.)

If you decide to go down the genetics rabbithole, I encourage you to work with someone well-trained in genetics because how genes or SNPs ultimately impact your body is much more complicated than simply addressing each SNP one by one.

Especially because other factors can also impact how much DAO is available (like when it’s suppressed due to certain medication exposures) or a vicious cycle of histamine + estrogen that just makes everything worse (I’ll discuss this more in a moment).

For most, doing a “test” by taking supplemental DAO 10 minutes before every meal for a month to see if you notice any improvement might be more helpful. (Remember, DAO enzymes aren’t right for everyone which I discussed in Part 1.)

BUT even then, discovering that DAO supplements help doesn’t necessarily mean you’ve hit on a root cause per se.

Woman thinking about estrogen dominance

Estrogen’s Role In Histamine Overload

If you truly do fall into the Histamine Overload bucket, it’s crucial to rule out estrogen dominance.

Estrogen is a very necessary sex hormone that can cause some serious troublemaking in your system when it’s out of balance. I previously discussed related topics in episode 72 and episode 180 that you may want to check out.

Just from a reactivity standpoint, one study showed that women may be more reactive to the allergens for a skin prick test between days 12-16 of their cycle when estrogen spikes.(1)

So if we know that monthly hormonal fluctuations can impact how reactive you are to histamines, what happens if estrogen is outright too high in your body?

One potential concern comes from research suggesting that estrogen could increase the number of histamine receptors making you even more sensitive to histamine.(2)

In addition to this, the crazy estrogen-histamine relationship you’ve probably never heard of is truly something of great concern!

Lara Briden wrote an excellent article about this exact scenario on her website in 2020 called “The Curious Link Between Estrogen, Mast Cells and Histamine.”

She penned this explanation so articulately that I’m just going to share it exactly as written — “Estrogen stimulates mast cells to release histamine and down-regulates the DAO enzyme that clears histamine. At the same time, histamine stimulates the ovaries to make more estrogen. The net result can be a vicious cycle of estrogen → histamine → estrogen → histamine.(3)

Do you see the problem?

Before you think this is a women’s only problem — sorry guys, this can also happen to you too! Men also have estrogen naturally occurring in their body, just at lower levels than women, opening up the potential to end up with too much should the right circumstances come to fruition.

And you can’t just blame your ovaries (ladies) or testes (men) for this mess either! I discussed in Episode 190 on Phase 3 Liver Detox that gut and liver detox dysfunction could be the part of your root cause combo fueling higher estrogen levels.

So yeah… investigating estrogen dominance is a MUST if you’re really having a hard time with histamine.

Vials of blood from estrogen dominance test

Testing For Estrogen Dominance

While it might be tempting to seek out hormone testing after listening to all of this, it might also not be very helpful.

The reason is that there are so many factors at this point hijacking your body’s natural ability to deal with histamines. So addressing JUST estrogen might not be the best solution since so many other systems are involved.

In my clinical practice, comprehensive stool testing like a GI Map that looks for the beta-glucuronidase level in your stool is helpful enough. I discuss in PART 1 how to address this type of issue as you work through your case.

You can also give the DAO enzymes a try from a digestive perspective or the other supplement suggestions like immunoglobulins that I also mentioned in PART 1.

I’m not saying NOT to get hormone panels run, but I’ve often found that you won’t get very far with the data. It’s often better to get the gut and liver issues more balanced before testing hormones.

But again… that’s been my clinical experience and obviously you should work directly with your practitioner to determine what’s the best course forward for you.

If you’ve got any questions or thoughts to share about this, leave a comment below so I can address them.

And take a moment to share this episode with everyone you know who is struggling with a histamine overload issue. This information is not widely known and so sharing it could be a HUGE eye opener for someone else dealing with hidden estrogen issues in the mix.

Thank you so much for tuning in and I look forward to seeing you in the next episode!

Woman with reference books in library


  1. http://apjai-journal.org/wp-content/uploads/2018/01/4IsthemenstrualcycleaffectingVol22No4December2004P197-1.pdf
  2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4013143/
  3. https://www.larabriden.com/the-curious-link-between-estrogen-and-histamine-intolerance/

You have genes that code for two very important enzymes that dictate histamine breakdown -- HMNT and DAO.

Jennifer Fugo, MS, CNS

Jennifer Fugo, MS, CNS is an integrative Clinical Nutritionist and the founder of Skinterrupt. She works with women who are fed up with chronic gut and skin rash issues discover the root causes and create a plan to get them back to a fuller, richer life.

Follow Us

Medical Disclaimer

Skinterrupt offers health, wellness, fitness and nutritional information which is designed for educational purposes only. You should not rely on this information as a substitute for, nor does it replace, professional medical advice, diagnois, or treatment. If you have any concerns or questions about your health, you should always consult with a physician or other health care professional. Do not disregard, avoid, or delay obtaining medical or health related advise from your physician or other health care professional because of something you may have seen or read on our site, or in our advertising, marketing, or promotional materials. The use of any information provided by Skinterrupt is solely at your own risk.

Nothing stated or posted on our site, or in our advertising, marketing or promotional materials, or through any of the services we offer, as intended to be, and must not be taken to be, the practice of medicine or counseling care. For purposes of this disclaimer, the practice of medicine or counseling care includes, without limitation, nutritional counseling, psychiatry, psychology, psychotherapy, or providing health care treatment, instruction, diagnosis, prognosis, or advice.