ANAHEIM, California — Although allergies to flaxseed are rare, with its growing popularity it should be on allergists' radar, according to specialists. The seed and its oil are increasingly found in foods, art supplies, cosmetics, lotions, and animal feed.
Two challenging cases of flaxseed-related allergy were presented at the American College of Allergy, Asthma and Immunology (ACAAI) Annual Meeting on Friday. The cases provide further evidence that flaxseed can cause allergic reactions after both ingestion and contact with the skin.
In one case, an 18-month-old toddler developed an allergic reaction after eating oatmeal premixed with flaxseed. The boy developed a rash over his face and chest within 20 minutes of eating the oatmeal containing about 1,800-2,200 mg of flaxseed protein. It was the first time he had eaten flaxseed, and the rash went away within four hours. After blood immunoglobulin E (IgE) levels were tested, the boy was diagnosed with IgE-mediated reaction to flaxseed.
Flaxseed allergy is rarely reported in children, according to Alana Xavier De Almeida, MD, a resident in the Jackson Health system in Miami, Florida. She presented a case of a toddler who experienced anaphylaxis after consuming artist's oil paints that contained flaxseed. The toddler's parents were offered an oral flaxseed challenge test to confirm the diagnosis but declined. De Almeida suspects that this kind of allergy may be underreported in general because patients or their families may not make the connection between the symptoms and flaxseed as the cause.
On Friday, Richard M. Harris, MD, with Allergy and Asthma Associates of Los Angeles Medical Group in California, presented another case of a patient with recurring rashes on her hands who ultimately underwent allergy testing. The patient was found to have a severe flaxseed allergy that caused her skin to become inflamed and itchy. Her doctor recommended avoiding all sources of flaxseed, including food and personal care products such as lotions and shampoos. Harris also highlighted that some foods may contain traces of flaxseed even if they do not appear to be obvious sources of the allergen.
Harris' team took a history and asked her to bring in all materials she used in her painting, including charcoal, paint, and brush-cleaning solutions. Upon reviewing the items, it was discovered that her oil paints contained linseed/flaxseed-based oil. According to Harris, "People don’t think to look for it."
To further investigate the presence of flaxseed oil in the patient's paints, Patch testing was conducted using test wells taped onto the back of the patient's hands. The results showed significant reaction at 48 and 72 hours post-test.
After informing Medscape Medical News about her experience, Harris explained how her allergy had caused painful fissuring in her fingers, which affected her painting ability for at least a year before the flaxseed was identified as the relevant allergen. She was advised to switch to a non-linseed paint.
It is important to note that allergy to flaxseed is not entirely new; cases have been documented in literature for many decades.
The potential for flaxseed allergies is not new, but recent cases have raised concerns about its prevalence and the need for increased awareness. In 2010, Dr. Andrew O’Keefe, an allergist in St. John’s, Newfoundland, Canada, and his colleagues published a report detailing four cases of flaxseed allergy in children aged 17 months to 8 years old. The symptoms reported included urticaria, tingling, vomiting, and angioedema of the lips.
In 2022, another case was reported in the Journal of Allergy and Clinical Immunology Global by Dr. Mark Holbreich, an allergist in private practice in Indianapolis, Indiana. He reported a case of severe flaxseed anaphylaxis in an 11-month-old infant after regular contact with a flaxseed-stuffed animal. The paper concluded that flaxseed sensitization most likely occurred through skin exposure and emphasized the need for allergists to be aware of this possibility.
While these two papers are not part of Friday’s presentation by De Almeida or Harris, they suggest that more research is needed to better understand the prevalence and risk factors for flaxseed allergies. As a result, it is important for allergists to be aware of these cases and for patients with a history of allergy to be cautious when consuming flaxseed products.
The first case involving an infant was reported, highlighting the increasing concern over flaxseed as a potential cause of anaphylaxis or contact dermatitis. According to Dr. Holbreich, who is affiliated with the department of pediatrics at Children's Memorial Hospital in Chicago and is a professor at Loyola University Medical Center, "flaxseed has been implicated in many other cases."
The abstracts published in the Journal of Allergy and Clinical Immunology suggest that flaxseed might be a culprit for those suffering from allergies or contact dermatitis. The authors report their findings on 24 children and adolescents who were experiencing symptoms related to anaphylaxis after consuming foods containing flaxseed.
Dr. Marcia Frellick, a freelance journalist based in Chicago, Illinois, who covered this story, states: "Flaxseed is increasingly important as a potential cause of anaphylaxis or contact dermatitis." She adds that "it seems like everyone is talking about it."
Despite the growing concern, the FDA has not yet taken any action regarding the safety of flaxseed. In response to media inquiries, a spokesperson from the agency stated that they have "no reason to suspect food allergens in [the] diet are a problem." However, Dr. Holbreich warns that consumers should be aware of potential risks associated with consuming products containing flaxseed and seek medical attention if they experience symptoms.
