BRIEF REPORT Brief Report: ‘‘Allergic Symptoms’ ’ in Children with Autism Spectrum Disorders. More than Meets the Eye?

Abstract Many children with Autism Spectrum Disor-ders (ASD) have either family and/or personal history of ‘‘allergic symptomatology’’, often in the absence of posi-tive skin or RAST tests. These symptoms may suggest mast cell activation by non-allergic triggers. Moreover, children with mastocytosis or mast cell activation syndrome (MCAS), a spectrum of rare diseases characterized by increased number of activated mast cells in many organs, appear to have ASD at a rate tenfold higher (1/10 children) than that of the general population (1/100 children). Mast cell activation by allergic, infectious, environmental and stress-related triggers, especially perinatally, would release pro-inflammatory and neurotoxic molecules. We speculate these could disrupt the gut–blood–brain barriers, thus contributing to brain inflammation and ASD pathogenesis. Increased mast cell responsiveness may define at least a subgroup of ASD subjects, who could benefit from inhi-bition of mast cell activation