Q:

10/14/2013
I recently evaluated a 10 year-old boy for fire ant allergy. At the age of six he was bitten by several fire ants which resulted in generalized urticaria without any other symptoms. He was given a prescription for self-injectable epinephrine at that time. He has not received any fire ant bites since his initial reaction at the age of 6. His mother brought him in to determine if he still needed to have self-injectable epinephrine available at all times.

1) Should children who experience cutaneous reactions alone to either fire ant bites or venom stings receive a prescription for self-injectable epinephrine?

2) Should these children undergo skin testing a few years after their initial cutaneous reaction to determine if they have lost their IgE mediated sensitization?

3) If skin testing to is negative can they then be told that they no longer need to carry self-injectable epinephrine?

A:

Thank you for your inquiry.

Unfortunately we do not have as much data regarding the epidemiology and outcome of fire ant stings as we do for flying hymenoptera. Therefore, much of the therapeutic strategy we apply to fire ant is actually derived from data obtained by studying patients who have reacted to flying hymenoptera. Therefore it is less evidence-based and cannot be taken as definitive. Nonetheless, our present guidelines (1) indicate that recommendations regarding immunotherapy for fire ant are generally the same as those regarding venom immunotherapy to flying hymenoptera.

With these observations in mind, I will try and answer your questions directly:
1. Although it is reasonably clear that children who experience cutaneous reactions only, if they do have a subsequent reaction, the symptoms remain cutaneous, it is still necessary, in my opinion, to prescribe an automatic epinephrine injector.

2. Since there is no indication to start immunotherapy to venom in children, there is, in my opinion, no need to retest these children. Anaphylactic events have occurred in patients with negative skin tests on rare occasion, and therefore finding negative skin tests would not alter plans for therapy, in my opinion, in this child.

3. Based upon the above observations, obviously, I would not discontinue the prescription of an automatic epinephrine injector in this case.

Unfortunately, we do not know enough about the epidemiology of fire ant reactions to know when and if a person is no longer at risk. So, we do not know exactly when to stop prescribing automatic epinephrine injectors, but safety being the first concern, at least in my opinion I would continue to prescribe them in your child.

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

Reference:
1. Golden DBK, et al. Stinging insect hypersensitivity: a practice parameter update 2011. J Allergy Clin Immunol 2011; 127(4):852-854.

Sincerely,
Phil Lieberman, M.D.

AAAAI - American Academy of Allergy Asthma & Immunology