Anaphylaxis is classified as idiopathic when notrigger can be identified and currently representsbetween 6.5 and 35.0% of cases, depending onthe studies.45 In such cases, mast cell disordersshould be ruled out. Excluding urticariapigmentosa does not exclude mastocytosis,neither does a normal baseline tryptase.Detecting KIT mutation in peripheral blood or inbone marrow may be necessary.46,47 Also, therole of allergens previously unrecognized (suchas alpha-Gal)48 or less straightforward to identify(omega-5-gliadin, oleosins)49 has to beconsidered.