Management of Idiopathic Anaphylaxis: When Is Bone Marrow Examination Essential?

Abstract

Idiopathic anaphylaxis is not an uncommon entity within the Allergy and Immunology field. Management of such patients can be extremely challenging at times. A thorough history, including an emphasis on possible mast cell disease, is an absolute necessity. A bone marrow biopsy is not only appropriate, but essential, when evaluating patients with recurrent anaphylaxis if a clonal mast cell disease is suspected as the underlying etiology. Clinical predictors for underlying clonal mast cell disease have been studied and include an elevated baseline tryptase, presence of hypotensive syncopal episodes, and absence of urticaria and angioedema during anaphylactic episodes. In the acute setting, there is no alternative to self-injectable epinephrine for treatment of suspected anaphylaxis of any type. It should be administered with repeated doses as deemed necessary to establish resolution of symptoms such as hypotension, bronchospasm, or cardiovascular collapse. Once the diagnosis of idiopathic anaphylaxis is made, we recommend starting maintenance therapy with a regimen of H1 antihistamines. Cases who are refractory to H1 antihistamine therapy alone will require the addition of at least low dose immune suppression with corticosteroids to provide continued relief from recurrent episodes. In many cases these medications can be weaned in less than a year without recurrent symptoms. In refractory cases or corticosteroid-dependent idiopathic anaphylaxis, adjunctive therapy with second line agents including montelukast or omalizumab has been used with some success.