Arugula allergy
Question:
12/30/2024
I had a 14-year-old female with new onset of palatal inflammation, redness and pain that lasts a few days for the past nine months after eating arugula. Prior ingestion of arugula and all leafy green vegetables have been fine. On a few occasions she had some throat closing sensation and chest tightness which were relieved with Benadryl. One was with arugula exposure and one with a mixed Spring Salad from Wendy's (has other items such as pecans and cranberries which she eats otherwise with no issues). She has no issues with spinach, iceberg lettuce, romaine lettuce and continues to eat them. She does not remember but feels in England, when this all started, watercress may have led to the mouth issues. Never required Epi and never had any other overt symptoms nor wheezing I suspect based on her history. She has no issues with other fruits or vegetables and mild spring-time allergy symptoms. I have never seen a true IgE mediated lettuce allergy and I am confused about next steps. Her symptoms are mostly local apart from those few times where some SOB/throat symptoms occurred (unsure if maybe PFAS). However, they are worried as they feel over time the symptoms have been getting progressively worse. It is interesting she continues to eat some types of lettuce/greens and I cannot find labs in our area that will do arugula IgE (or watercress or cabbage). I have not run the lettuce IgE test yet but unsure if it would be helpful given I assume it would include a variety of greens and would not be able to pinpoint the variety or if this story could be concerning enough for this eventually leading to developing symptoms with all forms of lettuce/leafy greens.
Answer:
This patient has symptoms very consistent with oral allergy syndrome or pollen food allergy syndrome (PFAS) to arugula. This is a rare, unique case because arugula allergy is rare and this is occurring in a pediatric patient. Her treatment response is consistent with an IgE-mediated mechanism and histamine mediated symptoms. Arugula is Eruca sativa and reports of IgE-mediated reaction induced by arugula causing symptoms have been reported. E sativa belongs to the Brassicaceae or Cruciferae family, which includes other vegetables such as cabbage, cauliflower, mustard, broccoli, turnip and radish. Arugula is a food of the Mediterranean diet and it is commonly used as a condiment in many dishes (pizza, pasta and salad), consumed raw or cooked. (1)
The Brassicaceae are able to cause sensitization and IgE-mediated reactions. Rare cases of adverse reactions after arugula ingestion have been reported, such as contact or systemic manifestations like urticaria.(1-4) Because PFAS is IgE mediated, your patient’s symptoms are likely IgE mediated and she can be skin testing to raw arugula. If she has classic PFAS, raw arugula will cause symptoms on oral food challenge while extremely cooked arugula will not cause symptoms. In all reported cases of arugula allergy, the diagnosis was confirmed by prick and prick skin testing to only the raw, native food with negative testing to the cooked prick and prick, when performed. (1-3)
In the cases described in the literature, cross reactive food skin tests were also positive for raw radish (1) and parsley (3), but no clinical symptoms to the foods occurred. Arugula allergic patients who were skin tested for aeroallergens were either negative to all aeroallergens by extract (4) or positive to grass pollen, Parietaria (flowering plants), and cat dander. (1,3) PFAS is caused by cross reactivity with pollen IgE sensitization and studies of arugula allergic patients demonstrate IgE to proteins consistent with proteins of molecular weight ~60---67 kDa (1) and 12 kD (3), the latter being the size of profilin, a clinically relevant food allergen. (5) Previous arugula allergy cases have not described clinical reactions with theoretically cross reactive foods, so I would be less worried about other food causing symptoms in this patient. Watercress is reported to be the cause of contact dermatitis, but not IgE mediated symptoms.
I recommend skin testing this patient to raw arugula and, if positive, diagnosing her with PFAS. I would not challenge this patient if her symptoms happened recently. Assess for environmental IgE mediated sensitization, especially to grass pollen.
References
1. Damiani E, Aloia AM, Priore MG, Pastore A, Lovecchio A, Errico M, Ferrannini A, Macchia L. IgE-mediated reaction induced by arugula (Eruca sativa) ingestion compared with a spectrum of Brassicaceae proteins. Allergol Immunopathol (Madr). 2014 Sep-Oct;42(5):501-3. doi: 10.1016/j.aller.2013.05.003. Epub 2013 Jul 4. PMID: 23830923.
2. Pigatto PD, Bigardi A, Fumagalli M, Legori A, Altomare GF. Ig-E-mediated contact and generalized urticaria from Eruca sativa. Contact Dermatitis. 1991;25:191---2.
3. Foti C, Cassano N, Mistrello G, Amato S, Romita P, Vena GA. Contact urticaria to raw arugula and parsley. Ann Allergy Asthma Immunol. 2011 May;106(5):447-8. doi: 10.1016/j.anai.2011.01.029. Epub 2011 Feb 26. PMID: 21530883.
4. Liccardi G, Salzillo A, Mistrello G, Roncarolo D, D’Amato M, D’Amato G. Intraoral and respiratory allergy to Eruca sativa (Cruciferae family) in a subject with sensitization to pollen allergens. J Allergy Clin Immunol. 1998;101:559–560.
5. Asero R, Monsalve R, Barber D. Profilin sensitization detected in the office by skin prick test: a study of prevalence and clinical relevance of profilin as a plant food allergen. Clin Exp Allergy. 2008 Jun;38(6):1033-7. doi: 10.1111/j.1365-2222.2008.02980.x. Epub 2008 Apr 13. PMID: 18489029.
Carla M. Davis, MD, FAAAAI