Telling The Difference Between Food Allergies and Histamine Intolerance

What's the Difference Between Food Allergy and an Intolerance?

Histamine intolerance is a fairly foreign topic for most people, including doctors.

Oftentimes it’s mistaken as an allergic reaction, and for good reason too. Allergic reactions cause almost identical symptoms to that of histamine intolerance, making it almost indistinguishable in some cases.

Because of this, histamine intolerance is extremely under-diagnosed which might explain why only 1% of the population currently suffers from it. Luckily, there are a few ways to tell if you’re experiencing an allergic reaction or if you’re histamine intolerant.


Common Symptoms of Histamine Intolerance

Histamine intolerance symptoms include:

  • Itching, especially of the skin, eyes, ears, and nose
  • Hives (red, itchy spots or blotches on skin)
  • Flushing or reddening of skin
  • Swelling around face and mouth, and sometimes throat
  • Throat tightening
  • Blocked or runny nose
  • Irritated, watery, reddened eyes
  • Digestive problems (e.g. heartburn, indigestion, reflux)
  • Drop in blood pressure.
  • Increase pulse rate.
  • Heart racing
  • Chest pain
  • Symptoms resembling anxiety or panic attack (e.g. difficulty breathing, heart racing, sweaty, faint, sense of terror)
  • Headaches
  • Psychological symptoms (e.g. confusion, irritability)

Sounds like an allergic reaction, right? That’s because the body releases histamine during allergic reactions.

In this case, the immune system mistakes an allergen as a threat and immediately releases defense chemicals (e.g. histamine). But remember, this is immediate. You see with food allergies even the smallest amount of a specific food triggers an immediate reaction, while histamine intolerance depends on the total amount of histamine in the body. (In fact, normal levels of histamine fall between 0.3 to 1.0 ng/mL.) So, a small amount of histamine will not cause any symptoms, but if the total amount is above what your body needs a reaction will occur. This is why you might feel fine after eating histamine-rich foods or drinks, but start experiencing symptoms several hours later. This happens because the body’s total level of histamine gradually rises throughout the day, eventually overwhelming enzymes’ (e.g. DAO and HNMT) to the point they cannot break down anymore histamine.

Histamine Intolerance Chart

What You Can Do

Before assuming you are histamine intolerant, I suggest visiting your doctor to rule out any other conditions that could be causing your symptoms. Here are a few things you can do:

  1. Ask your doctor to conduct a blood and skin test to check for any allergies
  2. Ask your doctor to test if you have mast cell activation disorder (MCAD)
  3. Have your doctor check if you have an autoimmune disease
  4. Try a histamine-restricted diet for at least two weeks

Once you have completed Steps 1-3 and all three have negative results as well as follow a histamine-restricted diet that improved your symptoms, it’s safe to assume you’re a HIT.

Unfortunately we live in a world in which histamine intolerance is poorly understood and often goes unnoticed. As for those who are HIT, it’s impossible to ignore. By sharing our stories and what we already know, we can change the current status quo so every HIT can enjoy their life and food once again.