Heterogeneity in presentation and treatment of catamenial anaphylaxis

Progestogen Hypersensitivity

Progestogen hypersensitivity (PH) is a heterogeneous disease characterized by diverse cutaneous manifestations, bronchospasm, and/or anaphylaxis. Possible triggers include ovarian progesterone and exogenous progestogens. The timing of symptoms is critical to diagnose PH: during the luteal phase of the menstrual cycle for the endogenous form and after exposure to progestins for exogenous PH. Diagnostic modalities such as progesterone skin testing have low sensitivity and specificity for PH. When exogenous PH is suspected, the allergist should consider a progestogen challenge. Treatment strategies should be tailored for each patient, including symptom-directed therapies, ovulation suppression, and progesterone desensitization. Future studies should explore the mechanisms of PH, validation of diagnostic criteria, and standardization of treatment strategies.

Effect of Gender and Special Considerations for Women in Mastocytosis and Anaphylaxis

This article reviews the effects of gender on anaphylaxis in general and focuses on mastocytosis-specific issues. Incidence of anaphylaxis is increased in female compared with male patients during the pubertal years through the fifth decade of life, in which these disparities decrease. Estrogen is thought to increase the severity of anaphylaxis through increased endothelial nitric oxide synthase release. Despite this, all-cause fatal anaphylaxis does not appear to show a gender predilection. Systemic mastocytosis incidence is higher in women; however, mortality is increased in men owing to increased molecular and cytogenetic abnormalities.

Cofactors in food anaphylaxis in adults

Around 25% to 50% of food-induced allergic reactions in adults cause anaphylaxis, and epidemiologic evidence suggests that food is the most common cause of anaphylaxis. Reaction severity is unpredictable, and patients will often experience reactions of variable severity, even to an identical exposure (both dose and allergen). A common explanation for this phenomenon has been the impact of "cofactors"-factors that might contribute to reaction severity independent of the allergen exposure. Cofactors can influence reaction severity in 2 ways: either by reducing the reaction threshold (ie, the dose needed to trigger any symptoms) so that patients have no symptoms in the absence of the cofactor and only react with the cofactor present, or by increasing reaction severity such that individuals have only mild symptoms in the absence of the cofactor, but a more severe reaction when the cofactor is present. Indeed, the same patient may have reactions with different cofactors or even need more than one cofactor to develop a severe reaction. Cofactors reportedly play a role in approximately 30% of anaphylaxis reactions in adults. Exercise, nonsteroidal, anti-inflammatory drugs, alcohol, and sleep deprivation are the most frequent cofactors reported. Routine evaluation of the possible involvement of cofactors is essential in managing patients with food anaphylaxis: in patients with a suggestive history but a negative oral food challenge, cofactors should be taken into account to provide appropriate advice to reduce the risk of future anaphylaxis.

Anaphylaxis: Long-term management and resources

Background: Anaphylaxis is an acute life-threatening event that requires emergent diagnosis and treatment. However, focus on prevention of anaphylaxis is essential in reducing anaphylaxis recurrences and associated mortality. Objective: This literature review was aimed to be a comprehensive resource for practicing allergists in managing anaphylaxis in the long term. We discussed the role of the allergist in the long-term outpatient management of anaphylaxis through identifying risk factors, allergen avoidance, prevention of recurrences, and patient education. Methods: A medical literature search that focused on several areas of long-term management of anaphylaxis was conducted. Results: Patients evaluated by an allergist are more likely to have their anaphylaxis trigger identified, to have their underlying mast cell disorder diagnosed, and to receive desensitization or allergen immunotherapy. Allergists can prevent fatal anaphylaxis by preventing and treating anaphylaxis in patients with ischemic heart disease and by optimally treating patients with comorbid asthma. Allergists can offer specific prevention strategies for allergenic trigger and cofactor avoidance. Education should be focused on patients with a higher risk for recurrence of anaphylaxis, such as those patients with a history of severe symptoms or anaphylaxis, with a peanut and/or tree nut trigger, or with a history of asthma, or female gender. Patient counseling involves providing individualized action plans at each visit and discussing proper use, storage, and safety of epinephrine autoinjectors. Multiple doses of epinephrine need to be prescribed to those who are at risk for severe food-induced, venom immunotherapy-related, or venom-induced anaphylaxis. Wording on medical identification products should be reviewed by the allergist. Anaphylaxis resources for health-care providers are summarized in the article. Conclusion: Ongoing education, providing personalized anaphylaxis action plans, reducing risk factors, and avoiding triggers are key to anaphylaxis prevention and long-term management.

Hormonal Effects on Urticaria and Angioedema Conditions

Women appear to be more frequently affected with urticaria and angioedema. Sex hormones are believed to have an important mechanistic role in regulating pathways involved in these conditions. This effect is likely nonspecific for chronic spontaneous urticaria (CSU) or many forms of angioedema (AE), because many other chronic diseases such as asthma are also affected by sex hormones. The role of sex hormones has been better elucidated for hereditary AE, because they have been shown to have multiple effects including upregulation of FXII, an important activator of the kallikrein pathway. However, their role in the underlying pathogenesis for CSU is less clear. Autoimmunity is clearly linked to CSU, which is more common in women. This suggests that sex hormones could act as adjuvants in activating or upregulating autoimmune pathways. The purpose of this review is to discuss in detail the role of sex hormones in CSU and AE and how a better understanding of the impact hormones has on these conditions might lead to new treatment advancements with better clinical outcomes.

Review of icatibant use in the Winnipeg Regional Health Authority

BACKGROUND

This is a retrospective review of the Winnipeg Regional Health Authority's (WRHA) angioedema patients who were dispensed icatibant in hospital. Icatibant is a bradykinin B2 receptor antagonist indicated for Hereditary Angioedema (HAE) types I and II and is used off-label for HAE with normal C1INH (HAE-nC1INH) and ACE-inhibitor induced angioedema (ACEIIAE). The WRHA's use of icatibant is regulated by the Allergist on call. We characterized icatibant's use and the timeline from patient presentation, compared the real-world experience with the FAST-3 trial and hypothesized the factors which may affect response to icatibant.

METHODS

Background data were collected on patients. Angioedema attack-related data included administered medications, performed investigations and the timeline to endpoints such as onset of symptom relief. Data was analyzed in R with the package "survival." Time-to-event data was analyzed using the Peto-Peto Prentice method or Mann-Whitney U-test. Data was also compared with published clinical trial data using the Sign Test. Fisher's Exact Test was used to produce descriptive statistics.

RESULTS

Overall, 21 patients accounted for 23 angioedema attacks treated with icatibant. Approximately half the patients had a diagnosis of HAE-nC1IHN and half of ACEIIAE. Of those presenting with angioedema, 65% were first treated with conventional medication. Patients without a prior angioedema diagnosis were evaluated only 40-50% of the time for C4 levels or C1INH function or level. The median time from patients' arrival to the emergency department until the Allergy consultant's response was 1.77 h. Patients with HAE-nC1IHN had median times to onset of symptom relief and final clinical outcome (1.13 h, p = 0.34; 3.50 h, p = 0.11) similar to those reported in FAST-3 for HAE I/II. Patients with ACEIIAE had longer median times to onset of symptom relief (4.86 h, p = 0.01) than predicted.

CONCLUSIONS

HAE-nC1INH may be an appropriate indication for treatment with icatibant. Conversely, the results of this study do not support the use of icatibant for the treatment of ACEIIAE, concordant with a growing body of literature. Patients should be stratified into groups of more- or less-likely icatibant-responders through history and laboratory investigations in order to prevent potential delays.

Estrogen and estrogen receptor signaling promotes allergic immune responses: Effects on immune cells, cytokines, and inflammatory factors involved in allergy

Hypersensitivity occurs when the body is stimulated by an antigen, resulting in an immune response, and leads to a physiological disorder or abnormal tissue trauma. Various immune cells, cytokines, and inflammatory mediators are involved in the immune responses related to allergic diseases, which are the core of anaphylaxis. Estrogen receptors are widely distributed in immune cells, which combine with estrogen and participate in allergic responses by affecting immune cells, cytokines, and inflammatory factors. We aimed to summarize the association between estrogen and allergic reactions to provide a scientific basis for understanding and studying the mechanisms of allergic diseases.

Mechanisms, Cofactors, and Augmenting Factors Involved in Anaphylaxis

Anaphylaxis is an acute and life-threatening systemic reaction. Many triggers have been described, including food, drug, and hymenoptera allergens, which are the most frequently involved. The mechanisms described in anaphylactic reactions are complex and implicate a diversity of pathways. Some of these mechanisms may be key to the development of the anaphylactic reaction, while others may only modify its severity. Although specific IgE, mast cells, and basophils are considered the principal players in anaphylaxis, alternative mechanisms have been proposed in non-IgE anaphylactic reactions. Neutrophils, macrophages, as well as basophils, have been involved, as have IgG-dependent, complement and contact system activation. A range of cationic substances can induce antibody-independent mast cells activation through MRGPRX2 receptor. Cofactors and augmenting factors may explain why, in some patients, food allergen exposure can cause anaphylaxis, while in other clinical scenario it can be tolerated or elicits a mild reaction. With the influence of these factors, food allergic reactions may be induced at lower doses of allergen and/or become more severe. Exercise, alcohol, estrogens, and some drugs such as Non-steroidal anti-inflammatory drugs, angiotensin-converting enzyme inhibitors, β-blockers, and lipid-lowering drugs are the main factors described, though their mechanisms and signaling pathways are poorly understood.

Progestogen Hypersensitivity: An Evidence-Based Approach to Diagnosis and Management in Clinical Practice

Heterogeneous presentations of disease pose particular diagnostic and management challenges to the clinician. Progestogen hypersensitivity (PH) classically consists of hypersensitivity symptoms to endogenous progesterone during the luteal phase of the menstrual cycle. However, with the rise of assisted fertility and the exponential growth in the use of exogenous progestins for contraception, PH's prevalence and symptom heterogeneity have increased. In this article, we focus on the clinical approach to PH diagnosis with an emphasis on key elements of the history, physical, and testing modalities. We also review the current evidence for successful management and treatment across a broad range of patients.

Anaphylaxis

Anaphylaxis is a systemic, life-threatening disorder triggered by mediators released by mast cells and basophils activated via allergic (IgE-mediated) or nonallergic (non-IgE-mediated) mechanisms. It is a rapidly evolving, multisystem process involving the integumentary, pulmonary, gastrointestinal, and cardiovascular systems. Anaphylaxis and angioedema are serious disorders that can lead to fatal airway obstruction and culminate in cardiorespiratory arrest, resulting in hypoxemia and/or shock. Often, these disorders can be appropriately managed in an outpatient setting; however, these conditions can be severe enough to warrant evaluation of the patient in the ED and in some cases, hospitalization, and management in an ICU. Reports suggest that underdiagnosis and undertreatment of anaphylaxis are common. Several new syndromes have been described recently including bird-egg, pork-cat, delayed allergy to mammalian meat and a diverse group of mast cell activation disorders. Conditions such as postural orthostatic tachycardia syndrome, carcinoid syndrome, Munchausen stridor, and factitious anaphylaxis can present similarly and need to be included in the differential diagnosis. Anaphylaxis is a clinical diagnosis, but plasma tryptase and urinary histamine levels are often elevated, allowing diagnostic confirmation; however, diagnostic testing should not delay treatment as results may not be immediately available. The sine qua non of treatment is avoidance of any known triggers and epinephrine, which should never be delayed if this disorder is suspected. Secondary treatments include fluids, bronchodilators, antihistamines, and glucocorticoids. Patients with cardiopulmonary arrest or airway or vascular compromise require mechanical ventilation, vasopressors, and other advanced life support in the ICU.

Epinephrine for First-aid Management of Anaphylaxis

Anaphylaxis is a severe, generalized allergic or hypersensitivity reaction that is rapid in onset and may cause death. Epinephrine (adrenaline) can be life-saving when administered as rapidly as possible once anaphylaxis is recognized. This clinical report from the American Academy of Pediatrics is an update of the 2007 clinical report on this topic. It provides information to help clinicians identify patients at risk of anaphylaxis and new information about epinephrine and epinephrine autoinjectors (EAs). The report also highlights the importance of patient and family education about the recognition and management of anaphylaxis in the community. Key points emphasized include the following: (1) validated clinical criteria are available to facilitate prompt diagnosis of anaphylaxis; (2) prompt intramuscular epinephrine injection in the mid-outer thigh reduces hospitalizations, morbidity, and mortality; (3) prescribing EAs facilitates timely epinephrine injection in community settings for patients with a history of anaphylaxis and, if specific circumstances warrant, for some high-risk patients who have not previously experienced anaphylaxis; (4) prescribing epinephrine for infants and young children weighing <15 kg, especially those who weigh 7.5 kg and under, currently presents a dilemma, because the lowest dose available in EAs, 0.15 mg, is a high dose for many infants and some young children; (5) effective management of anaphylaxis in the community requires a comprehensive approach involving children, families, preschools, schools, camps, and sports organizations; and (6) prevention of anaphylaxis recurrences involves confirmation of the trigger, discussion of specific allergen avoidance, allergen immunotherapy (eg, with stinging insect venom, if relevant), and a written, personalized anaphylaxis emergency action plan; and (7) the management of anaphylaxis also involves education of children and supervising adults about anaphylaxis recognition and first-aid treatment.

Sexual dimorphism in the mast cell transcriptome and the pathophysiological responses to immunological and psychological stress

Background

Biological sex plays a prominent role in the prevalence and severity of a number of important stress-related gastrointestinal and immune-related diseases including IBS and allergy/anaphylaxis. Despite the establishment of sex differences in these diseases, the underlying mechanisms contributing to sex differences remain poorly understood. The objective of this study was to define the role of biological sex on mast cells (MCs), an innate immune cell central to the pathophysiology of many GI and allergic disorders.

Methods

Twelve-week-old C57BL/6 male and female mice were exposed to immunological stress (2 h of IgE-mediated passive systemic anaphylaxis (PSA)) or psychological stress (1 h of restraint stress (RS)) and temperature, clinical scores, serum histamine, and intestinal permeability (for RS) were measured. Primary bone marrow-derived MCs (BMMCs) were harvested from male and female mice and analyzed for MC degranulation, signaling pathways, mediator content, and RNA transcriptome analysis.

Results

Sexually dimorphic responses were observed in both models of PSA and RS and in primary MCs. Compared with male mice, female mice exhibited increased clinical scores, hypothermia, and serum histamine levels in response to PSA and had greater intestinal permeability and serum histamine responses to RS. Primary BMMCs from female mice exhibited increased release of β-hexosaminidase, histamine, tryptase, and TNF-α upon stimulation with IgE/DNP and A23187. Increased mediator release in female BMMCs was not associated with increased upstream phospho-tyrosine signaling pathways or downstream Ca²⁺ mobilization. Instead, increased mediator release in female MCs was associated with markedly increased capacity for synthesis and storage of MC granule-associated immune mediators as determined by MC mediator content and RNA transcriptome analysis.

Conclusions

These results provide a new understanding of sexual dimorphic responses in MCs and have direct implications for stress-related diseases associated with a female predominance and MC hyperactivity including irritable bowel syndrome, allergy, and anaphylaxis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13293-016-0113-7) contains supplementary material, which is available to authorized users.

Estrogen increases the severity of anaphylaxis in female mice through enhanced endothelial nitric oxide synthase expression and nitric oxide production

BACKGROUND

Clinical observations suggest that anaphylaxis is more common in adult women compared with adult men, although the mechanistic basis for this sex bias is not well understood.

OBJECTIVES

We sought to document sex-dependent differences in a mouse model of anaphylaxis and explore the role of female sex hormones and the mechanisms responsible.

METHODS

Passive systemic anaphylaxis was induced in female and male mice by using histamine, as well as IgE or IgG receptor aggregation. Anaphylaxis was assessed by monitoring body temperature, release of mast cell mediators and/or hematocrit, and lung weight as a measure of vascular permeability. A combination of ovariectomy, estrogen receptor antagonism, and estrogen administration techniques were used to establish estrogen involvement.

RESULTS

Anaphylactic responses were more pronounced in female than male mice. The enhanced severity of anaphylaxis in female mice was eliminated after pretreatment with an estrogen receptor antagonist or ovariectomy but restored after administration of estradiol in ovariectomized mice, demonstrating that the sex-specific differences are due to the female steroid estradiol. Estrogen did not affect mast cell responsiveness or anaphylaxis onset. Instead, it increased tissue expression of endothelial nitric oxide synthase (eNOS). Blockage of NOS activity with the inhibitor L-NG-nitroarginine methyl ester or genetic eNOS deficiency abolished the sex-related differences.

CONCLUSION

Our study defines a contribution of estrogen through its regulation of eNOS expression and nitric oxide production to vascular hyperpermeability and intensified anaphylactic responses in female mice, providing additional mechanistic insights into risk factors and possible implications for clinical management in the further exploration of human anaphylaxis.

Factors augmenting allergic reactions

Elicitors of anaphylactic reactions are any sources of protein with allergenic capacity. However, not all allergic reactions end up in the most severe form of anaphylaxis. Augmenting factors may explain why certain conditions lead to anaphylaxis. Augmenting factors may exhibit three effects: lowering the threshold, increasing the severity, and reversing acquired clinical tolerance. Common augmenting factors are physical exercise, menstruation, NSAIDs, alcohol, body temperature, acute infections, and antacids. Therapeutic options may address causative, preventive, pragmatic, or symptomatic considerations: avoid the eliciting food, take an antihistamine before any situation with a possible risk of augmentation, separate food and sport (at least for 2 h), and carry an adrenaline autoinjector at all times. Individual patterns include summation effects and specific patterns. In conclusion, in the case of a suggestive history but a negative oral challenge, one should consider the possible involvement of augmenting factors; after anaphylactic reactions, always ask for possible augmentation and other risk factors during the recent past; if augmentation is suspected, oral food challenges should be performed in combination with augmenting factors; and in the future, standardized challenge protocols including augmenting factors should be established.

International consensus on (ICON) anaphylaxis

ICON: Anaphylaxis provides a unique perspective on the principal evidence-based anaphylaxis guidelines developed and published independently from 2010 through 2014 by four allergy/immunology organizations. These guidelines concur with regard to the clinical features that indicate a likely diagnosis of anaphylaxis -- a life-threatening generalized or systemic allergic or hypersensitivity reaction. They also concur about prompt initial treatment with intramuscular injection of epinephrine (adrenaline) in the mid-outer thigh, positioning the patient supine (semi-reclining if dyspneic or vomiting), calling for help, and when indicated, providing supplemental oxygen, intravenous fluid resuscitation and cardiopulmonary resuscitation, along with concomitant monitoring of vital signs and oxygenation. Additionally, they concur that H1-antihistamines, H2-antihistamines, and glucocorticoids are not initial medications of choice. For self-management of patients at risk of anaphylaxis in community settings, they recommend carrying epinephrine auto-injectors and personalized emergency action plans, as well as follow-up with a physician (ideally an allergy/immunology specialist) to help prevent anaphylaxis recurrences. ICON: Anaphylaxis describes unmet needs in anaphylaxis, noting that although epinephrine in 1 mg/mL ampules is available worldwide, other essentials, including supplemental oxygen, intravenous fluid resuscitation, and epinephrine auto-injectors are not universally available. ICON: Anaphylaxis proposes a comprehensive international research agenda that calls for additional prospective studies of anaphylaxis epidemiology, patient risk factors and co-factors, triggers, clinical criteria for diagnosis, randomized controlled trials of therapeutic interventions, and measures to prevent anaphylaxis recurrences. It also calls for facilitation of global collaborations in anaphylaxis research. IN ADDITION TO CONFIRMING THE ALIGNMENT OF MAJOR ANAPHYLAXIS GUIDELINES, ICON: Anaphylaxis adds value by including summary tables and citing 130 key references. It is published as an information resource about anaphylaxis for worldwide use by healthcare professionals, academics, policy-makers, patients, caregivers, and the public.