I'm a dermatologist, and I frequently treat patients with challenging cases due to skin allergies.
One of my friends came to see me because she kept experiencing a severe red rash on her face. She had multiple flares of this very red and very itchy rash on her eyelids, forehead, and jawline. After patch testing, we discovered that she had a fragrance allergy. She had reacted to both fragrance mix and a substance called balsam of Peru, both of which are forms of fragrance additives. This actually wasn't a big surprise, because fragrance additives are one of the top causes of allergic skin reactions in the United States.
I gave her a list of products that were safe for her to use, and she proceeded to change all of her skin care products. She changed her hair care products and laundry products also. She did a great job, and 8 weeks later she was much better.
However, in the months that followed, she would still experience occasional flares of her facial rash.
That's when we decided to go further, and eliminate certain foods that are related to fragrance allergies. After following this elimination diet for the next 6 weeks, she finally had clear skin.
Why would people with fragrance allergy have to avoid certain foods?
When patients don't respond to elimination of fragrance in their skin and hair care products, it may be because they are responding to related substances that they are ingesting. In my friend's case, I was concerned about this possibility, which indicates a type of allergy known as systemic contact dermatitis.
Systemic contact dermatitis occurs when patients who are allergic to certain chemicals on their skin also react when they're exposed to that chemical via systemic routes. This exposure can occur by eating the substance (via foods), by inhaling the substance, or by intravenous exposure.
In persons with SCD, eating a certain food may trigger a worsening of their dermatitis. (This doesn't happen in everyone, and we're not sure why it happens for some people.)
This flare may take place many hours (or even days) later, which can make it hard to determine the culprit food.
SCD is considered one type of food allergy, but it's not the type that's picked up by the usual food allergy testing.
That's because there are different types of food allergies, and different parts of the immune system that are involved.
That means that different tests are needed for different types of food allergies.
Skin prick tests and blood tests usually test for IgE-mediated food allergies. IgE-mediated allergy is a type of food allergy that is more immediate-it usually occurs within minutes to hours after exposure to a certain food.
To diagnose SCD, patch testing is required.
What foods can trigger systemic contact dermatitis?
There are several food triggers of SCD. These include
processed foods that contain propylene glycol
and foods that are related to balsam of Peru, which is a type of fragrance additive
What foods can trigger systemic contact dermatitis in persons with fragrance allergy?
What are the foods to avoid in balsam of Peru allergy?
The main foods related to fragrance additives are
Tomatoes
Citrus, including oranges and lemons
Cinnamon
Other related foods include certain spices, such as vanilla and cloves.
Because of the cinnamon, vanilla, and cloves, I'll often advise my patients to avoid baked goods as part of this elimination diet.
Other flavorings can be an issue, such as the flavorings in soft drinks, specifically cola drinks.
I've also had some patients react to certain flavored liquers, while some have reacted to certain flavored teas.
Chocolate is another related food.
Hearing about the chocolate factor (!) can be upsetting. But it's important to realize that even if patients react to certain foods related to Balsam of Peru, they don't usually react to all of the foods. With my patients, in fact, I've found that most people react mainly to one or two of these foods.
What do we know about the science behind fragrance allergy and the balsam of Peru avoidance diet?
Many people are surprised to learn that fragrance additives are actually related to some very common foods. One of the fragrance additives that I frequently test is called balsam of Peru. This is a natural substance, derived from a tree, and it breaks down into certain chemical constituents. Some of these chemical constituents are related to foods.
In one small study, researchers studied a group of patients who were allergic to fragrance additives, but whose skin did not improve even after changing all of their skin care products.
They asked this group of patients to eliminate certain foods from their diet.
After 8 weeks, approximately half of these patients finally experienced significant or complete improvement of their skin.
For these patients, eliminating these foods from their diet was what finally helped clear their skin.
How long before you'll know if this balsam of Peru allergy elimination diet is helping?
I advise patients that it can take up to 6 weeks of avoiding these foods to see if it will help their skin.
If they do improve, then I'll ask them to slowly add these foods back to their diet.
Add back one food every week and see if it triggers a flare of the rash.
Most people can handle some (or even most) of these foods, and adding them back in slowly can help pinpoint which ones are triggers.