Journal of oncology pharmacy practice : official publication of the International Society of Oncology Pharmacy Practitioners •
Alpha-gal syndrome (AGS) is a hypersensitivity disorder in which tick bites-most commonly from the lone star tick ()-trigger immunoglobulin E-mediated hypersensitivity reaction upon exposure to oligosaccharide galactosse-alpha-1,3-galactose (α-gal). α-gal is most notorious for being found in "red meat" products but is present in mammalian meats such as beef, pork, lamb, rabbit, and others. Manifestations of AGS hypersensitivity are variable. There is currently no data describing allergic reactions against rabbit products in patients with AGS. Here, we describe a case of a 44-year-old male with myelodysplastic syndrome and a known history of AGS undergoing allogeneic hematopoietic cell transplantation (allo-HSCT) with the use of rabbit antithymocyte globulin (rATG) for graft-versus-host disease (GVHD) prophylaxis. The risk of cross-reactivity against rATG in our patient with AGS could not be ruled out and, therefore, a test dose was administered. The patient tolerated the test dose with no signs of anaphylaxis. After demonstrating tolerance to the test dose, rATG was utilized for GVHD prophylaxis. Due to the heterogeneity of AGS manifestations in patients, the use of rATG in patients with known AGS should be considered on a case-by-case basis. The administration of a test dose may help predict the occurrence of severe hypersensitivity reactions. The limited data surrounding the risk of AGS with rabbit-containing products and the various indications for the use of rATG warrants more in-depth study of the reactivity of this medication in this population.
The journal of allergy and clinical immunology. In practice •
Anaphylaxis is a severe and potentially life-threatening allergic reaction. Since its discovery over 100 years ago, research has led to great strides in describing pathophysiologic mechanisms of anaphylaxis; however, there is still imprecision regarding its definition and a lack of reliable, confirmatory testing. In this paper, we review definitions of anaphylaxis, highlighting studies examining the utility of the current clinical consensus definition. In addition, we evaluate current difficulties and limitations for both providers in acute care settings managing episodes and allergists evaluating patients after an episode has resolved. Finally, we provide an algorithm for outpatient evaluation of patients with a history of possible anaphylaxis.
Pattanaik D, Lieberman P, Lieberman J, Pongdee T, Keene AT
Annals of allergy, asthma & immunology : official publication of the American College of Allergy, Asthma, & Immunology •
Our institution has published serial studies of adults and adolescents with anaphylactic events. The first series was published in 1993 and the last was published in 2006. It was our perception that the nature of anaphylactic episodes had changed over the 2 decades since the last review. To determine whether the etiologies and presentations of anaphylaxis have changed during the past decade in our population. Patient charts were identified based on International Classification of Diseases, Ninth Revision codes for anaphylactic shock. Charts identified were analyzed for clinical symptoms reported, comorbidities, etiology, investigative testing, and subsequent treatment. These cases were categorized as definitive, probable, or idiopathic based on history and results from testing, similar to our prior reports. We identified 281 possible cases, of which 218 met criteria for anaphylaxis. Of these cases, median age was 42 years (range 9-78) and 64% were female. In the review of cases, 85 (39%) were determined to have a definitive etiology, 57 were determined to have a probable etiology (26%), and 76 (35%) were idiopathic. Interestingly, of those with a definitive cause, the most common etiology identified was galactose-α-1,3-galactose, accounting for 28 cases (33%). Foods were the second leading cause, accounting for 24 cases (28%). In this follow-up report on anaphylaxis etiology from a single center, the most common etiology was galactose-α-1,3-galactose. This differs greatly from prior reports from our center. Interestingly, the percentage of cases attributed to idiopathic anaphylaxis decreased from 59% in our previous report to 35% in the present report, which could largely be explained by the number of galactose-α-1,3-galactose cases.
The journal of allergy and clinical immunology. In practice •
Idiopathic anaphylaxis is a perplexing problem that accounts for approximately 30% to 60% of cases of anaphylaxis in ambulatory adults and perhaps 10% of cases in children. Advances in our knowledge of idiopathic anaphylaxis have occurred over the past decade with the elucidation of mast cell activating disorders and the discovery of episodes of anaphylaxis caused by galactose-alpha-1,3-galactose. Most patients do well because fatalities can usually be prevented with proper therapy, and many individuals, for reasons not understood, undergo spontaneous remission.
Idiopathic anaphylaxis is not uncommon and can be found in as many as 60% of patients referred to an allergist for anaphylactic events. It is an extremely frustrating condition for patients because they have no means of avoiding a known allergen and events occur spontaneously and unprovoked. The objective of this study was to synthesize and review the medical literature on idiopathic anaphylaxis and present a strategy for diagnosis, prevention, and treatment of episodes. A literature review was performed after a search of PubMed using the key words of idiopathic anaphylaxis. Idiopathic anaphylaxis is more common in adults than in children and in women than in men. The symptoms and signs are identical to those found in other causes of anaphylaxis. Perhaps the most common entities to be considered in the differential diagnosis are somatoform reactions. The two most recent advances in our ability to detect the cause are the discovery that episodes can be caused by mast cell-activating syndromes, systemic mastocytosis, and IgE to galactose-alpha-1,3-galactose. Patients experiencing idiopathic anaphylactic episodes should, if possible, avoid taking drugs that may complicate therapy or worsen a reaction. Fortunately, the vast majority of cases follow a benign course. Although many recurrent episodes of anaphylaxis remain idiopathic, recent advances in our knowledge, especially the description of mast cell-activating disorders and the discovery of anaphylactic reactions to galactose-α-1,3-galactose have allowed us to find causes in events that previously would have been classified as idiopathic. In addition, the majority of such patients exhibit a diminishing frequency of reactions over time and can be managed in a way that prevents mortality and a severe effect on their quality of life.