7/9/2012
I have a 1 month old that recently had an episode concerning anaphylaxis. The parents introduced Enfamil when the baby was 32 days old. Prior to that, he had been breastfed (although he had received Enfamil once in the hospital and once at 2 weeks of age). During the feeding, Mom noted fussiness. After 1.5 ounces, he refused to eat. Mom noted that he was "sweaty" and that his ears were “puffy”. He developed a rash that was described as "red with white bumps". They noted that his lips were swollen and there was concern that he was having some mild difficulty breathing. No vomiting or diarrhea. They brought him to the ED, where the physician there noted "lip and tongue swelling", a "generalized urticarial rash" over the "entire face, trunk and abdomen", and a "hoarse screaming with mild subcostal retractions, very little air movement." He had pulse oximetry that was 96%. It does not appear that a blood pressure was obtained. His pulse was 172-188. He was given 0.1mg of IM Epinephrine, 10 mg IV methylprednisilone, 5 mg Diphenhydramine, 9 mg of IV ranitidine and IV fluids. The ED physician noted that the respiratory distress was “resolved” and his “swelling and urticaria has gotten much better.” He was then transferred to a local Children's hospital ICU where he was observed overnight. The parents note that he was doing much better at the time of transfer and his symptoms were nearly resolved. He was started on Neocate in the ICU, was observed and then discharged home the next day. No labwork was obtained.

I saw him the next day and he looked great. I observed a vigorous baby that was eating well. Exam was completely negative with the exception of some typical baby acne on his cheeks. I obtained a blood culture that would be negative, a total tryptase that was 2.9 ng/ml, an Immunocap for cow's milk that was 3.79 kU/L. He has since had some spitting up and a diagnosis of GERD. He was placed on Ranitidine which parents report has been effective. Also over the 2 week period since this happened, he has gained weight well and has been developing appropriately. He has continued on Neocate.

If he was older, this would seem like a straight forward type 1 food allergy to cow's milk; however, the patient's young age is concerning to me.

Would you recommend any additional work-up? Are there additional diagnoses I ought to consider? How early can one expect to see true type 1 food allergy?

Thank you for your inquiry.

I am asking Dr. Scott Sicherer, who is an internationally known expert in food allergy and anaphylaxis in infants, to comment on your question. As soon as we receive a response from Dr. Sicherer, we will forward it to you.

Thank you again for your inquiry.

Sincerely,
Phil Lieberman, M.D.

We received a response from Dr. Scott Sicherer regarding your Ask the Expert inquiry. Thank you again for your inquiry and we hope this response is helpful to you.

Sincerely,
Phil Lieberman, M.D.

Response from Dr. Scott Sicherer:

I agree that this seems awfully early for anaphylaxis but all of the details appear to fit: introduction of a food after a period of abstinence (milk), a common allergen (milk), immediate reaction after that ingestion, multiple symptoms consistent with anaphylaxis, no apparent alternative explanations, a positive IgE test to the apparent trigger, and, apparently, no symptoms, physical exam abnormalities or lab abnormalities apart from the event.  

The differential diagnosis (partial) of SOME of these symptoms in an infant could include: urticaria pigmentosa/mastocytosis,  respiratory (upper or lower) obstruction, congenital problems (eg, laryngeal web, vascular ring), aspiration, bronchiolitis, asthma, asphyxiation/suffocation, breath-holding, gastrointestinal issues (eg, intussusception), septic shock, cardiovascular problems, central nervous system issues (seizure,  trauma, child abuse, increased intracranial pressure), metabolic disorders, infection, toxins, etc.  

The tryptase levels run a bit higher in younger children,(1) but the baseline here was normal.     

Given your presentation, it seems like food induced anaphylaxis as you give no real indication of other issues to consider.

For a wonderful discussion of infant anaphylaxis please see the review article by Dr. Estelle Simons.(2)

Reference List
  (1) Komarow HD, Hu Z, Brittain E, Uzzaman A, Gaskins D, Metcalfe DD. Serum tryptase levels in atopic and nonatopic children. J Allergy Clin Immunol 2009; 124(4):845-848.

  (2) Simons FE. Anaphylaxis in infants: can recognition and management be improved? J Allergy Clin Immunol 2007; 120(3):537-540.

Scott H. Sicherer, MD
Professor of Pediatrics
Jaffe Food Allergy Institute
Mount Sinai School of Medicine
New York, NY