Thank you for your inquiry.
I am not going to be able to give you a definitive answer. I can only summarize the little information we have related to your inquiry and try and help you draw a reasonable conclusion.
First of all, what we do know is as follows:
1. It is clear that almond allergens can be contained in almond oil. The reference that you listed, however, is the only one that I am aware of or could find giving any information on this topic. For our readers, I have copied the full abstract below.
2. We also know that the topical application of oil can sensitize.
3. On the other hand, I could not find any case of anaphylaxis to almond oil via the topical route, in the literature but clearly there is an admonition to avoid almond oil completely if one has demonstrated an allergy to almond. These admonitions occur on lay websites, you can find one here.
Even taking all of these things into consideration, we do not, as noted, have a definitive answer. But because of the admonition noted on lay websites which is quite clear and explicit, the fact that almond oil can contain almond allergens, and finally the fact that we know cutaneous sensitization can occur, I would think that the most prudent thing to do is avoid almond oil completely if a patient has demonstrated allergy to almond oil. Certainly, if the allergen were present in a significant amount and there was any abrasion or small laceration, theoretically an allergic event could occur due to the topical application of the oil based on the above observations.
Thank you again for your inquiry and we hope this response is helpful to you.
Journal of Allergy and Clinical Immunology
Volume 99, Issue 4, Pages 502–507, April 1997 Abstract
Background: No information is available on allergenicity of tree nut oils, and information on peanut oils has been conflicting. Many of the nut oils now on the market undergo minimal processing and may contain residual antigen. Objective: This study was carried out to determine whether several of the new “gourmet” tree nut oils, as well as peanut oils, contain residual proteins that could bind IgE from sera of patients with allergy. Methods: Several brands of walnut, almond, hazelnut, pistachio, and macadamia nut oils were examined. Peanut oils, both unrefined oils (which have been shown to contain allergenic proteins) and refined oils (without previously demonstrable allergens), were also examined to confirm reproducibility of immunoreactivity as reported by other investigators. Oils were extracted with 0.2 mol/L ammonium bicarbonate, and protein concentrations in the aqueous extracts were measured. IgE binding was assayed by slot-blot and Western immunoblotting. Pooled sera from patients with a history of systemic reactions to various tree nuts or peanuts were used as appropriate. Results: The oil extracts known to be from oils that had undergone less processing at lower temperatures tended to demonstrate qualitatively greater IgE binding and higher protein concentrations.
Conclusion: Tree nut and peanut oils may pose a threat to patients with allergy, depending on the method of manufacture and processing. (J Allergy Clin Immunol 1997;99:502-6.)
Allerg Immunol (Paris). 2000 Oct;32(8):309-11.
[Percutaneous sensitization to almond oil in infancy and study of ointments in 27 children with food allergy
Guillet G1, Guillet MH.
A five month old child with atopic dermatitis developed contact dermatitis to almond with positive patch test, positive prick test, and class 4 anti-almond IgE. Focal lesions of persistent eczema were correlated with application of almond oil for 2 month on cheeks and buttocks. The child had not ingested almond and her mother did not report almond intake during her breast-feeding. This observation points to the problems of possible percutaneous sensitisation to food proteins. The study of skin ointments containing components of food origin in 27 food sensitized atopic patients confirm that the choice of an ointment for lesional skin is of importance.
Phil Lieberman, M.D.