March Week 3: Allergies & Skin Testing


  1. Cartwright R, et al. Consultation with the Specialist: Who Needs Allergy Testing and How to Get It Done. Peds in Review. 2006;27;140-146.
  2. Lasley M, et al. Testing For Allergy. Peds in Review. 2000;21;39-43.

Case 1:

You are seeing a 15 month old girl in your clinic for worsening eczema. Mom reports that her eczema worsened around the time she began eating solid foods. She read in a magazine that she could either have testing to diagnose her eczema or try an elimination diet to try to figure out what the child is allergic to. She would like guidance on how to go about this.

What do you advise the mother? 
What are the different types of allergic reactions? 
For which type(s) of allergic reactions is testing available? 
What helps determine which allergens to test a patient for? 
What etiologies can lead to false positive and false negative skin testing results? 
What are the advantages and disadvantages of skin vs serum allergy testing?

Prep questions:

1. A 10 yo boy presents to clinic after an insect sting reaction. He was playing in his yard yesterday when he was stung on the right forearm by a wasp. His parents are worries becayse when he awaoke today, the redness that initially was localized to the sting site had extended to involve his entire right forearm. He has no other findings and vital signs are normal. His right forearm is diffusely erythematous and warm but not tender. This reaction is BEST characterized as:
A. cellulitis
B. large local reaction
C. normal reaction
D. systemic anaphylaxis
E. toxic reaction

2. A 9 yo girl is stung by a hornet. Within 10 minutes, she develops diffuse pruritis and a large area of erythema at the site. Five minutes later, extensive welts appear on her trunk and extremities. She is rushed to the ER where IV antihistamine and steroids are given. She has no difficulty breathing or swallowing. Her symptoms resolve gradually over 4 hours. The NEXT recommended step in her management is:
A. admit for observation
B. discharge the patient home
C. perform skin testing to all hymenoptera within 72 hours
D. prescribe oral antihistamine for girl to take before playing outside
E. start allergy shots to hornet