Q:

9/23/2013
Pt is a 2y 10m boy with 2q microdeletion syndrome, seen in allergy clinic due to asthma and food allergy. He has an anaphylactic reaction to milk at 4 months of age. Skin test at 17m was positive to milk (3 mm), egg (4 mm), and peanut (20 mm) and he has been avoiding them. Last month, he got a piece of cookie and a bite of cheese from his brother and had a severe reaction with generalized hives, facial swelling, and difficulty breathing. He was treated with epinephrine injection and observed in ER. That time, it was thought that either milk or egg in the cookies and cheese was the trigger.

He is starting daycare but is behind on immunizations and never had MMR vaccine, since his mother was afraid of vaccines that might have egg in it. Discussed with her that MMR is not contraindicated in egg allergy and we could also do MMR desensitization. We followed blood work which was positive to egg but not very high (class 3, 4.23Ku/l), and very high to milk (class 5, 50.4 ku/l), with the total IgE of 240 ku/l. I thought milk was likely to be the cause of anaphylactic reaction and plan to do MMR desensitization. At this point, skin prick test was done which was positive to egg (8 mm) but negative to milk (not sure why, could be an error) and the MMR scratch test was very big at 10 mm. Histamine control was 8 mm. Specific IgE to latex and gelatin were checked and both were negative. Would you recommend MMR desensitization given the large reaction to MMR scratch test?

A:

Thank you for your inquiry.

As you know, measles and mumps vaccines are prepared in chicken embryonic fibroblast culture, but contain negligible or no egg protein. Thus, several studies have shown that MMR is safe to administer in children with egg allergy. In fact, it has been suggested that children with egg allergy do not need skin testing with MMR vaccine. Nonetheless, I can understand your concern, and certainly, since a graded challenge with MMR is not a difficult procedure and can be done easily in the office, there is no harm in taking extra caution and administering the vaccine using such a graded administration protocol as is noted in Table 5 and Figure 1 of the reference below.

In summary, although there is no scientific evidence that this child is at risk of having an allergic reaction to MMR vaccine, in view of the circumstances, it would be prudent, if you have concern, to proceed with a graded challenge dose rather than administer the entire amount with one injection.

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

Reference:
Kelso J, et al. Adverse reactions to vaccines: Practice Parameter 2012 Update. J Allergy Clin Immnol 2012; 130(1):25-43.

Sincerely,
Phil Lieberman, M.D.

AAAAI - American Academy of Allergy Asthma & Immunology