RECALL URTICARIA IN PATIENT WITH CELIAC DISEASE

Abstract

<h3>Introduction</h3> Recall urticaria refers to an urticarial response localized to an area of prior antigen exposure and reactivated by various stimuli, typically allergy immunotherapy. Our case describes a patient, ultimately diagnosed with celiac disease, who experiences episodes of recall urticaria at site of previous allergy immunotherapy after ingestion of wheat. <h3>Case Description</h3> The patient is a 28-year-old female with allergic rhinitis previously on allergy immunotherapy from 2015-2016. In June 2020, she began to experience urticaria on the posterior region of her left arm. The episodes occurred in the evening, resolving within 20 minutes after diphenhydramine treatment. She described the location of hives to be consistent with area of prior immunotherapy injections. In July 2020, she started cetirizine 10mg every morning and diphenhydramine 25mg every evening, which controlled her hives outside of recurrence with missed antihistamines doses. She was later diagnosed with celiac disease and initiated a gluten-free diet. She discontinued oral antihistamines in February 2021 and remained free from frequent episodes of hives. However, with accidental ingestion of wheat, she reports a recurrence of localized hives 5-6 hours later. <h3>Discussion</h3> The patient's history of spontaneous localized hives where she previously received allergy immunotherapy is consistent with recall urticaria. Given the correlation between ingestion of wheat and episodes of urticaria, this appears to be her trigger for recall urticaria. Further investigations are underway, including skin prick and patch testing, with potential oral challenge to wheat. The mechanism by which the immune or inflammatory response to gluten triggers her recall urticaria remains to be elucidated.