Anaphylaxis as a Manifestation of Systemic Mastocytosis: A Case Report and Review of Literature

Introduction: Anaphylaxis is defined as “a serious, life-threatening generalized or systemic hypersensitivity reaction” and “a serious allergic reaction that is rapid in onset and might cause death”. The determination of different mast cells (MC) mediators, such as serum and/or plasma histamine and tryptase, is proposed for the diagnosis of anaphylaxis. There are differences in the clinical presentation of anaphylaxis in patients with indolent systemic mastocytosis versus idiopathic anaphylaxis. Case presentation: This is the case of a 72-year-old female patient presenting with acute bacterial pyelonephritis treated with intra venous antibiotics. She developed a facial flush then a diffuse flush with hypoxia and respiratory arrest. The patient recovered with non-invasive ventilation without the need for intubation. A full blood panel returned normal and two bone marrows biopsies were performed. The second one showed the presence of a perivascular infiltrate mast cell, consistent with systemic mastocytosis. Discussion: All aspects of systemic mastocyosis including the classification and the main clinical manifestations as well as the diagnosis were concisely reviewed. Then supportive and immunomodulator treatment were differentiated. Conclusion: Patients suffering of systemic mastocytosis typically present anaphylactic symptoms primarily involving the cardiovascular system in the absence of urticaria and/or angioedema, which makes such clinical presentation highly suspicious. Patients suffering of c-MCD (Cutaneous-mast cell disease) need assistance in identifying their triggers and education on proper avoidance.