Prevalence of Symptoms of Mast Cell Activation in Patients with Postural Orthostatic Tachycardia Syndrome and Hypermobile Ehlers‐Danlos Syndrome: 555

Abstract

Susan R. Fox, PA-C, MMS, Kathryn L. Hughes, Mary Mullen, MS, RDN, LDN, Mahboobeh Mahdavinia, MD PhD, Anil Kesavan, MD, andMary C. Tobin, MD FAAAAI; Department of Internal Medicine, Division of Allergy and Immunology, Rush University Medical Center, Chicago, IL, Department of Clinical Nutrition, College of Health Sciences, Rush University Medical Center, Chicago, IL, Pediatric Gastroenterology, Rush University Medical Center, Chicago, IL, Division of Allergy/Immunology, Department of Internal Medicine, Rush Univerisy Medical Center, Chicago, IL. RATIONALE: Diagnostic criteria have been established to diagnose MCAS in adults, however, the guidelines for children are unclear. Here we present a case series of children who presented to our multi-disciplinary, allergy/gastroenterology (GI) clinic with symptoms suggestive of MCAS who were found to have laboratory evidence of mast cell activation. METHODS: Children who presented to our clinic between 2014-2018 with a combination of non-IgE mediated adverse food reactions to more than one food, GI complaints, symptoms consistent with MCAS and at least one positive mast cell mediator marker per the adult criteria were included. RESULTS: The cases diagnosed as MCAS included a total of 15 children from 12months to 17 years of age. All had a history of abdominal pain with at least one other GI symptom and all had at least two symptoms consistent with MCAS. Eighty-seven percent of patients had an elevated mast cell mediator. The urine 2,3-dinor-11beta-prostaglandin F2 alpha (2,3 BPG) was the most common abnormal marker with 40% patients having a level greater than 5205pg/ml creatinine. All patients had improvement of GI symptoms with a combination of H1/H2 blockers and/or oral mast cell stabilizers. CONCLUSIONS: Most of the children in our case series were found to have MCAS according to adult diagnostic criteria. Checking urine mediators and a tryptase level should be considered in children with histories similar to our cohort as not to delay care. Further research is needed to establish diagnostic criteria for MCAS in children.