Q:

5/4/2012
MY patient had Mr.Whippy's ice cream and within minutes came up with rash and facial swelling. This happened on 2 occasions. The ingredients in this ice cream contain Kernal oil, locust bean, carragenan. Is RAST available for any of these?

A:

Thank you for your inquiry.

Of the three ingredients you noted in your inquiry, it appears the most likely candidate would be the locust bean. The other name for the locust bean (Ceratonia siliquia) is carob bean. There is a serum-specific IgE test (ImmunoCAP) available. Allergic reactions to carob bean have been previously reported (1).

In addition, carob pollen exposure by occupational inhalation has been noted to produce respiratory allergy (2).

Carrageenan has also been known to produce allergic reactions (see abstract copied below), but I could find no in vitro tests for serum-specific IgE to carrageenan. However, as you can see from the abstract, a skin test has been used to detect immediate hypersensitivity to carrageenan. You can purchase carrageenan powder if you wish to attempt a skin test to this substance.

Kernel oil usually refers to the oil from the palm. There is a serum-specific IgE to oil palm pollen (ImmunoCAP), but I could find no test for serum-specific IgE to kernel oil per se.

Thank you again for your inquiry and we hope this response is helpful to you.

The Journal of Allergy and Clinical Immunology, Volume 95, Issue 5 , Pages 933-936, May 1995
Abstract
Background: Anaphylactic reactions during a barium enema have been attributed to allergy to latex on the barium enema device. The observation of anaphylaxis during barium enema without latex exposure or latex allergy led to the performance of an allergy skin test to the barium enema solution.
Methods: Individual components of the barium enema solution were obtained for double-blind skin testing. A RAST to identify specific IgE antibodies to the skin test active agent was established.
Results: Carrageenan, a component of the barium enema solution, produced positive reactions to allergy skin test and RAST. Gastrointestinal symptoms for which the patient was being investigated by the barium enema subsequently disappeared with a diet free of carrageenan.
Conclusions: Carrageenan is a previously unreported cause of anaphylaxis during barium enema. It is an allergen widely distributed in common foods and potentially could account for some symptoms related to milk products or baby formula. (J Allergy Clin Immunol 1995;95:933-6).

References:
1. J Pediatr Gastroentero Nutr 1999; 29(4):475-476.
2. J Allergy Clin Immunol 1992; 90:1008-1010.

Sincerely,
Phil Lieberman, M.D.

AAAAI - American Academy of Allergy Asthma & Immunology