Hymenoptera sting anaphylaxis and urticaria pigmentosa: clinical findings and results of venom immunotherapy in ten patients

Clinician awareness of the risk of anaphylaxis in patients with cutaneous mastocytosis

The risk of anaphylaxis in maculopapular cutaneous mastocytosis (otherwise known as urticaria pigmentosa) is thought to be approximately 15%. Our survey of British Association of Dermatologists members elicited 40 responses: in patients with normal tryptase levels, adrenaline autoinjectors were prescribed for 10% of adults and 12% of children, increasing to 28% and 30% in those with raised tryptase. Of the 40 respondents, 95% felt a guideline would be beneficial. Thus, we propose a call for a guideline to assist clinicians with management of anaphylaxis risk in such patients, given the rarity of this condition.

Diagnosis and treatment of systemic mastocytosis in Brazil: Recommendations of a multidisciplinary expert panel

Introduction: Systemic Mastocytosis comprises a group of neoplastic diseases characterized by clonal expansion and infiltration of mast cells into several organs. The diagnosis and treatment of this disease may be challenging for non-specialists. Objective: Make suggestions or recommendations in Systemic Mastocytosis based in a panel of Brazilian specialists.

Method and results: An online expert panel with 18 multidisciplinary specialists was convened to propose recommendations on the diagnosis and treatment of Systemic Mastocytosis in Brazil. Recommendations were based on discussions of topics and multiple-choice questions and were graded using the Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence Chart.

Conclusion: Twenty-two recommendations or suggestions were proposed based on a literature review and graded according to the findings.

Hymenoptera venom-induced anaphylaxis and hereditary alpha-tryptasemia

PURPOSE OF REVIEW

To discuss the association between the common dominantly inherited genetic trait hereditary alpha-tryptasemia (HαT) and hymenoptera venom-induced anaphylaxis (HVA).

RECENT FINDINGS

Elevated BST has been correlated with more severe systemic anaphylaxis in humans in a number of settings - most notably in HVA. Clonal mast cell disease, in particular, systemic mastocytosis, is frequently associated with elevated BST, and is a major risk factor for severe HVA. However, clonal mast cell diseases are believed to be rare, whereas HVA is relatively more common. HαT affects an estimated 3-5% of Western populations and is the common cause for elevated BST in these individuals. An association between HαT and severe HVA, as well as clonal mast cell disease has recently been demonstrated wherein this trait modifies reaction severity in venom allergic individuals. A mechanism underlying this association has been proposed through the identification of naturally occurring heterotetrameric tryptases and characterization of their unique physical attributes.

SUMMARY

Here we discuss the long-standing association between elevated BST and HVA severity, how HαT fits into this landscape, and review the clinical and mechanistic evidence that supports HαT as a modifier of HVA.

Insect Sting Anaphylaxis-Or Mastocytosis-Or Something Else?

Insect sting anaphylaxis and mast cell disorders are intertwined in a specific and unusual way. There may be specific subsets of clonal mast cell disorders that are predisposed to sting anaphylaxis. The clinical characteristics of the sting reactions should raise suspicion of underlying mastocytosis (eg, hypotension without hives especially in a male). A baseline serum tryptase level is helpful in the evaluation of patients with insect sting anaphylaxis because it correlates with important risks for these patients, and they have a high frequency of abnormally elevated baseline levels. Elevated baseline serum tryptase level has been reported to correlate with clonal mast cell disease in patients with insect sting anaphylaxis but may also indicate one of several possible underlying syndromes, including mast cell activation syndrome (MCAS), familial hypertryptasemia, and idiopathic anaphylaxis. There is some overlap in these conditions, so it is important to evaluate the clinical pattern at presentation as well as laboratory markers, and to consider bone marrow biopsy to make a final and specific diagnosis of clonal mast cell disease. The presence of venom-IgE does not prove that the patient's previous sting reactions were IgE-mediated, but even low levels of venom-IgE in patients with mastocytosis predispose to severe sting anaphylaxis. Evaluation of all these possible factors will affect the recommendation for venom immunotherapy.

Component-resolved diagnosis in hymenoptera allergy

Component-resolved diagnosis based on the use of well-defined, properly characterised and purified natural and recombinant allergens constitutes a new approach in the diagnosis of venom allergy. Prospective readers may benefit from an up-to-date review on the allergens. The best characterised venom is that of Apis mellifera, whose main allergens are phospholipase A2 (Api m1), hyaluronidase (Api m2) and melittin (Api m4). Additionally, in recent years, new allergens of Vespula vulgaris have been identified and include phospholipase A1 (Ves v1), hyaluronidase (Ves v2) and antigen 5 (Ves v5). Polistes species are becoming an increasing cause of allergy in Europe, although only few allergens have been identified in this venom. In this review, we evaluate the current knowledge about molecular diagnosis in hymenoptera venom allergy.

Advances in the understanding and clinical management of mastocytosis and clonal mast cell activation syndromes

Clonal mast cell activation syndromes and indolent systemic mastocytosis without skin involvement are two emerging entities that sometimes might be clinically difficult to distinguish, and they involve a great challenge for the physician from both a diagnostic and a therapeutic point of view. Furthermore, final diagnosis of both entities requires a bone marrow study; it is recommended that this be done in reference centers. In this article, we address the current consensus and guidelines for the suspicion, diagnosis, classification, treatment, and management of these two entities.

Mastocytosis and Anaphylaxis

This article updates current knowledge on epidemiology, risk factors, triggers, and management of anaphylaxis in patients with mastocytosis. Hyperactive mast cells and higher number of effector mast cells are speculated to facilitate anaphylaxis in this condition. In children, increased risk is limited to those with extensive skin involvement and high tryptase. In adults, manifestations of anaphylaxis are severe with high frequency of cardiovascular symptoms. Hymenoptera stings are the most common triggers for these reactions; however, idiopathic anaphylaxis and reactions to food or drugs occur. Patients with mastocytosis should be informed about risk of anaphylaxis and prescribing emergency self-medication and installing emergency preparedness before general anesthesia is considered.

Added sensitivity of component-resolved diagnosis in hymenoptera venom-allergic patients with elevated serum tryptase and/or mastocytosis

BACKGROUND

Anaphylaxis caused by hymenoptera venom allergy is associated with elevation of baseline serum tryptase (sBT) and/or mastocytosis in about 5% of patients. Up to now, no information has become available on single venom allergen sIgE reactivity and the usefulness of component-resolved approaches to diagnose this high-risk patient group. To address the component-resolved sIgE sensitization pattern and diagnostic sensitivity in hymenoptera venom-allergic patients with elevated sBT levels and/or mastocytosis, a panel of yellow jacket and honeybee venom allergens was applied on a widely used IgE immunoassay platform.

METHODS

Fifty-three patients with mastocytosis and/or elevated sBT tryptase level and systemic reactions to hymenoptera venoms were analyzed for their IgE reactivity to recombinant yellow jacket and honeybee venom allergens by Immulite3 g.

RESULTS

sIgE reactivity to Ves v 1, Ves v 5, Api m 1 to Api m 4 and Api m 10 was found at a similar frequency in hymenoptera venom-allergic patients with and without elevated sBT levels and/or mastocytosis. However, the use of the recombinant allergens and a diagnostic cutoff of 0.1 kUA /L allowed the diagnosis of patients with otherwise undetectable IgE to venom extract. The diagnostic sensitivity of yellow jacket venom allergy using the combination of Ves v 1 and Ves v 5 was 100%.

CONCLUSIONS

In high-risk patients with elevated sBT levels and/or mastocytosis, the use of molecular components and decreasing the threshold sIgE level to 0.1 kUA /L may be needed to avoid otherwise undetectable IgE to hymenoptera venom extracts in about 8% of such patients.

When can immunotherapy for insect sting allergy be stopped?

BACKGROUND

Stings by Hymenoptera (honey bees, vespids, ants) can cause systemic allergic reactions (SARs). Venom immunotherapy (VIT) is highly effective and reduces an allergic patient's risk of a recurrent SAR to less than 5-20%. The risk of a recurrent SAR to a re-sting decreases the longer VIT is continued. The recommended duration of VIT is at least 3 to 5 years.

RISK FACTORS

Risk factors for recurrent SARs to a sting after stopping VIT have been identified and discussed: Recommendations concerning stopping VIT: For patients without any of the identified risk factors, VIT should be continued for 5 rather than 3 years. In patients with definite risk factors, a longer duration of VIT has to be discussed before stopping it. In mast cell disorders, VIT for life is recommended. Because of the residual risk of SARs after VIT, all patients are advised to carry an epinephrine autoinjector indefinitely and to continue to take measures to avoid Hymenoptera stings.

Hymenoptera Anaphylaxis and C-kit Mutations: An Unexpected Association

Clinical manifestations of mastocytosis in adults comprise signs and symptoms linked to mast cell (MC) activation, including anaphylaxis. Depending on MC burden, adults can be diagnosed with systemic mastocytosis, when the WHO criteria are fulfilled, or with other clonal MC disorders, characterized by MC mediator symptoms and demonstration of activating KIT mutations and/or expression of CD25 on MCs. There is a specific link between mastocytosis and hymenoptera venom allergy (HVA): the reported frequency of HVA in mastocytosis is 20-50 % and raises to 60-80 % in patients affected by indolent systemic mastocytosis without skin lesions. The presentation of HVA characterized by severe hypotension in the absence of urticarial or angioedema is typical in patient with an underlying MC disorder, even in the presence of normal baseline serum tryptase levels.

Risk factors and management of severe life-threatening anaphylaxis in patients with clonal mast cell disorders

Several different risk factors and conditions may predispose to severe life-threatening anaphylaxis. Systemic mastocytosis (SM) is one such condition. Although many SM patients are suffering from mild or even no mediator-related symptoms, others have recurrent episodes of severe anaphylaxis, with clear signs of a mast cell activation syndrome (MCAS) despite prophylactic therapy with anti-mediator-type drugs. In several of these patients, an IgE-dependent allergy is diagnosed. The severity and frequency of MCAS reactions neither correlate with the burden of neoplastic mast cells nor with the levels of specific IgE or the basal tryptase level. However, there is a relationship between severe anaphylaxis in SM and the type of allergen. Notably, many of these patients suffer from hymenoptera venom allergy. Currently recommended therapies include the prophylactic use of anti-mediator-type drugs, long-term immunotherapy for hymenoptera venom allergic patients, and epinephrine-self-injector treatment for emergency situations. In patients who present with an excess burden of mast cells, such as smouldering SM, cytoreductive therapy with cladribine (2CdA) may reduce the frequency of severe events. For the future, additional treatment options, such as IgE-depletion or the use of tyrosine kinase inhibitors blocking IgE-dependent mediator secretion as well as KIT activation, may be useful alternatives.

Anaphylaxis as a clinical manifestation of clonal mast cell disorders

Clonal mast cell disorders comprise a heterogeneous group of disorders characterized by the presence of gain of function KIT mutations and a constitutively altered activation-associated mast cell immunophenotype frequently associated with clinical manifestations related to the release of mast cells mediators. These disorders do not always fulfil the World Health Organization (WHO)-proposed criteria for mastocytosis, particularly when low-sensitive diagnostic approaches are performed. Anaphylaxis is a frequent presentation of clonal mast cell disorders, particularly in mastocytosis patients without typical skin lesions. The presence of cardiovascular symptoms, e.g., hypotension, occurring after a hymenoptera sting or spontaneously in the absence of cutaneous manifestations such as urticaria is characteristic and differs from the presentation of anaphylaxis in the general population without mastocytosis.

[IgE mediated anaphylaxis in a patient with systemic mastocytosis]

BACKGROUND

Anaphylaxis is a severe, generalized, life-threatening reaction of rapid onset. We report the case of a patient presenting several systemic anaphylactic reactions over many years, initially ascribed to a cereals allergy but which finally proved to be due to systemic mastocytosis hidden for a long time.

PATIENTS AND METHODS

A 53-year-old man consulted for an eruption consisting of monomorphic pigmented maculopapular lesions on the trunk associated with itching and urticaria. He was a farmer and presented severe sensitivity to cereals, with anaphylaxis, which continued despite withdrawal of these allergens. Skin and bone marrow infiltration, abnormal mast cells, positivity for c-kit 816 mutation and the persistent elevation of serum tryptase enabled a diagnosis of indolent systemic mastocytosis to be made.

DISCUSSION

In systemic mastocytosis anaphylaxis is an expected complication relating to the proliferation of mast cells and a massive increase in mediator release (non-immunological mechanism). All patients with severe and recurrent anaphylaxis should be analyzed for underlying mastocytosis by careful physical examination and assay of baseline tryptase.

How I treat patients with indolent and smoldering mastocytosis (rare conditions but difficult to manage)

Indolent systemic mastocytosis (SM) patients have a varied clinical presentation, ranging from predominantly cutaneous symptoms to recurrent systemic symptoms (eg, flushing, palpitations, dyspepsia, diarrhea, bone pain) that can be severe and potentially life threatening (anaphylaxis). Mastocytosis patients without skin involvement pose a diagnostic challenge; a high index of suspicion is needed in those with mast cell–degranulation symptoms, including anaphylaxis following Hymenoptera stings or other triggers. Modern-era molecular and flow-cytometric diagnostic methods are very sensitive and can detect minimal involvement of bone marrow with atypical/clonal mast cells; in some cases, full diagnostic criteria for SM are not fulfilled. An important aspect of treatment is avoidance of known symptom triggers; other treatment principles include a stepwise escalation of antimediator therapies and consideration of cytoreductive therapies for those with treatment-refractory symptoms. The perioperative management of mastocytosis patients is nontrivial; a multidisciplinary preoperative assessment, adequate premedications, and close intra- and postoperative monitoring are critical. Smoldering mastocytosis is a variant with high systemic mast cell burden. While its clinical course can be variable, there is greater potential need for cytoreductive therapies (eg, interferon-alpha, cladribine) in this setting. A systematic approach to the diagnosis and treatment of indolent SM using a case-based approach of representative clinical scenarios is presented here.

Importance of serum basal tryptase levels in children with insect venom allergy

BACKGROUND

The importance of serum basal tryptase (sBT) levels on patients with venom allergy is highlighted in recent adulthood studies. The aim of this study was to evaluate the sBT levels of venom-allergic children with varying severity of clinical reactions. We also aimed to document the association between sBT levels and severe systemic reactions (SR).

METHODS

Serum basal tryptase levels were estimated by UniCAP (Pharmacia & Upjohn, Uppsala, Sweden). Children who suffered from large local reaction (LLR) or SR after insect stings were included along with healthy control subjects without a history of any local or SR after insect stings.

RESULTS

A total of 128 children (55 with SR, 18 with LLR, and 55 age and sex-matched control subjects) with a median age of 8.9 years (range 3.2-17.4) were enrolled. Severe SR was encountered in 24 (44%) patients with SRs. The median level of sBT in children with SRs (median, interquartile range) [4.2 μg/l (3.6-4.9)] was significantly higher than in children with LLRs [3.1 μg/l (2.5-4.0)] and healthy control subjects [2.9 μg/l (2.3-3.4)] (P < 0.001). Logistic regression analysis revealed sBT ≥ 4.8 μg/l as a significant risk factor for severe SR (5.7 [1.5-21.4]; P = 0.01) in children with venom allergy.

CONCLUSIONS

Our results indicate that sBT levels are associated with a higher risk of severe SR in children with insect venom hypersensitivity. Determination of sBT levels may help clinicians to identify patients under risk of severe SRs and optimal and timely use of therapeutic interventions in children with venom allergy.

Management of insect sting hypersensitivity: an update

Reactions to Hymenoptera insect stings are common. While most are self-limited, some induce systemic allergic reactions or anaphylaxis. Prompt recognition, diagnosis, and treatment of these reactions are important for improving quality-of-life and reducing the risk of future sting reactions. This review summarizes the current recommendations to diagnose and treat Hymenoptera sting induced allergic reactions and highlights considerations for various populations throughout the world.

"It stings a bit but it cleans well": venoms of Hymenoptera and their antimicrobial potential

Venoms from Hymenoptera display a wide range of functions and biological roles. These notably include manipulation of the host, capture of prey and defense against competitors and predators thanks to endocrine and immune systems disruptors, neurotoxic, cytolytic and pain-inducing venom components. Recent works indicate that many hymenopteran species, whatever their life style, have also evolved a venom with properties which enable it to regulate microbial infections, both in stinging and stung animals. In contrast to biting insects and their salivary glands, stinging Hymenoptera seem to constitute an under-exploited ecological niche for agents of vector-borne disease. Few parasitic or mutualistic microorganisms have been reported to be hosted by venom-producing organs or to be transmitted to stung animals. This may result from the presence of potent antimicrobial molecules in venoms, histological features of venom apparatuses and selective effects of venoms on immune defenses of targeted organisms. The present paper reviews for the first time the venom antimicrobial potential of solitary and social Hymenoptera in molecular, ecological, and evolutionary perspectives.

Venom immunotherapy for preventing allergic reactions to insect stings

BACKGROUND

Venom immunotherapy (VIT) is commonly used for preventing further allergic reactions to insect stings in people who have had a sting reaction. The efficacy and safety of this treatment has not previously been assessed by a high-quality systematic review.

OBJECTIVES

To assess the effects of immunotherapy using extracted insect venom for preventing further allergic reactions to insect stings in people who have had an allergic reaction to a sting.

SEARCH METHODS

We searched the following databases up to February 2012: the Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library, MEDLINE (from 1946), EMBASE (from 1974), PsycINFO (from 1806), AMED (from 1985), LILACS (from 1982), the Armed Forces Pest Management Board Literature Retrieval System, and OpenGrey. There were no language or publication status restrictions to our searches. We searched trials databases, abstracts from recent European and North American allergy meetings, and the references of identified review articles in order to identify further relevant trials.

SELECTION CRITERIA

Randomised controlled trials of venom immunotherapy using standardised venom extract in insect sting allergy.

DATA COLLECTION AND ANALYSIS

Two authors independently undertook study selection, data extraction, and assessment of risk of bias. We identified adverse events from included controlled trials and from a separate analysis of observational studies identified as part of a National Institute for Health and Clinical Excellence Health Technology Assessment.

MAIN RESULTS

We identified 6 randomised controlled trials and 1 quasi-randomised controlled trial for inclusion in the review; the total number of participants was 392. The trials had some risk of bias because five of the trials did not blind outcome assessors to treatment allocation. The interventions included ant, bee, and wasp immunotherapy in children or adults with previous systemic or large local reactions to a sting, using sublingual (one trial) or subcutaneous (six trials) VIT. We found that VIT is effective for preventing systemic allergic reaction to an insect sting, which was our primary outcome measure. This applies whether the sting occurs accidentally or is given intentionally as part of a trial procedure.In the trials, 3/113 (2.7%) participants treated with VIT had a subsequent systemic allergic reaction to a sting, compared with 37/93 (39.8%) untreated participants (risk ratio [RR] 0.10, 95% confidence interval [CI] 0.03 to 0.28). The efficacy of VIT was similar across studies; we were unable to identify a patient group or mode of treatment with different efficacy, although these analyses were limited by small numbers. We were unable to confirm whether VIT prevents fatal reactions to insect stings, because of the rarity of this outcome.Venom immunotherapy was also effective for preventing large local reactions to a sting (5 studies; 112 follow-up stings; RR 0.41, 95% CI 0.24 to 0.69) and for improving quality of life (mean difference [MD] in favour of VIT 1.21 points on a 7-point scale, 95% CI 0.75 to 1.67).We found a significant risk of systemic adverse reaction to VIT treatment: 6 trials reported this outcome, in which 14 of 150 (9.3%) participants treated with VIT and 1 of 135 (0.7%) participants treated with placebo or no treatment suffered a systemic reaction to treatment (RR 8.16, 95% CI 1.53 to 43.46; 2 studies contributed to the effect estimate). Our analysis of 11 observational studies found systemic adverse reactions occurred in 131/921 (14.2%) participants treated with bee venom VIT and 8/289 (2.8%) treated with wasp venom VIT.

AUTHORS' CONCLUSIONS

We found venom immunotherapy using extracted insect venom to be an effective therapy for preventing further allergic reactions to insect stings, which can improve quality of life. The treatment carries a small but significant risk of systemic adverse reaction.

Venom immunotherapy in patients with mastocytosis and hymenoptera venom anaphylaxis

Systemic mastocytosis (SM) is typically suspected in patients with cutaneous mastocytosis (CM). In recent years, the presence of clonal mast cells (MCs) in a subset of patients with systemic symptoms associated with MC activation in the absence of CM has been reported and termed monoclonal MC activation syndromes or clonal systemic MC activation syndromes. In these cases, bone marrow (BM) MC numbers are usually lower than in SM with CM, there are no detectable BM MC aggregates, and serum baseline tryptase is often <20 µg/l; thus, diagnosis of SM in these patients should be based on careful evaluation of other minor WHO criteria for SM in reference centers, where highly sensitive techniques for immunophenotypic analysis and investigation of KIT mutations on fluorescence-activated cell sorter-purified BM MCs are routinely performed. The prevalence of hymenoptera venom anaphylaxis (HVA) among SM patients is higher than among the normal population and it has been reported to be approximately 5%. In SM patients with IgE-mediated HVA, venom immunotherapy is safe and effective and it should be prescribed lifelong. Severe adverse reactions to hymenoptera stings or venom immunotherapy have been associated with increased serum baseline tryptase; however, presence of clonal MC has not been ruled out in most reports and thus both SM and clonal MC activation syndrome might be underdiagnosed in such patients. In fact, clonal BM MC appears to be a relevant risk factor for both HVA and severe reactions to venom immunotherapy, while the increase in serum baseline tryptase by itself should be considered as a powerful surrogate marker for anaphylaxis. The Spanish Network on Mastocytosis has developed a scoring system based on patient gender, the clinical symptoms observed during anaphylaxis and serum baseline tryptase to predict for the presence of both MC clonality and SM among individuals who suffer from anaphylaxis.

Malignancy and specific allergen immunotherapy: the results of a case series

BACKGROUND

Specific immunotherapy with allergen is the only causative treatment for IgE-mediated allergies such as stinging insect allergy or hay fever and works by the induction of blocking antibodies and regulatory T lymphocytes.

OBJECTIVE

Does a hypothetical obstruction of tumor surveillance presupposing the induction of regulatory T cells really justify detaining immunotherapy to oncologic patients as suggested by recent guidelines?

METHODS

We report 6 patients (4 female, 2 male) suffering or having suffered from stage 1 cancer (4 melanomas, 1 lung cancer, 1 breast cancer) and concomitant IgE-mediated allergy. Four of them had a history of severe anaphylactic reactions to the insect yellow jacket, the 5th suffered from allergic rhinoconjunctivitis to dust mites, and the 6th to grass/rye pollen.

RESULTS

Between 2004 and 2010, subcutaneous immunotherapy was safely performed in 5 patients without signs of tumor reactivation. The cancer in 2 of them was diagnosed immediately after specific immunotherapy had been initiated and in another 2 the active cancer phase had already finished years before; the 5th suffered from a relapse around the time of the initiation of immunotherapy. At the time of the writing of the manuscript, 4 of them had already concluded 3 years of treatment, another one almost 1 year. The melanoma in the 6th patient was diagnosed 5 months after reaching the maintenance dose. Immunotherapy with grass/rye pollen was aborted in this patient based on current guidelines.

CONCLUSIONS

Specific immunotherapy was safely administered in patients suffering concomitantly from IgE-mediated allergy and lower stage cancer.

Influence of total and specific IgE, serum tryptase, and age on severity of allergic reactions to Hymenoptera stings

BACKGROUND

  The aim of this study was to analyze the influence of total serum IgE and other potential risk factors on severity of systemic allergic Hymenoptera sting reactions.

METHODS

  In a retrospective analysis of one thousand and two patients referred for insect allergy over 5 years, 865 reported systemic allergic sting reactions, most often by honey bees and wasps. In 758, total IgE, venom-specific IgE, and baseline tryptase levels were available and analyzed together with atopy state, age, and sex in relation to severity of sting reactions according to H. L. Mueller.

RESULTS

  In a binary logistic regression model considering, besides IgE, also other risk factors for severity, an influence of total and specific IgE on severity of systemic allergic sting reactions could not be shown, while high severity of systemic allergic sting reactions was significantly more often reported in patients with a baseline tryptase of ≥11.4 μg/l (P < 0.0001) and higher age (P = 0.026). In a bivariate analysis, however, in patients with grade IV reactions total IgE (P = 0.003) and honey bee venom-specific IgE (P = 0.001) were significantly lower than in lower severity grades. Bee venom-specific mean IgE rank was significantly higher in bee than in Vespula venom allergic patients (P = 0.0001).

CONCLUSIONS

  Connection of high severity sting reactions with lower IgE is mainly because of older age, which is associated with lower total IgE, and moreover with cardiovascular disease and elevated baseline serum tryptase, which are both risk factors for severe reactions.

Mastocytosis and insect venom allergy: diagnosis, safety and efficacy of venom immunotherapy

The most important causative factor for anaphylaxis in mastocytosis are insect stings. The purpose of this review is to analyse the available data concerning prevalence, diagnosis, safety and effectiveness of venom immunotherapy (VIT) in mastocytosis patients. If data were unclear, authors were contacted personally for further information. Quality of evidence (A: high, B: moderate, C: low and D: very low) and strength of recommendation (strong 1 and weak 2) concerning VIT in mastocytosis patients are assessed according to the Grading of Recommendations Assessment, Development and Evaluation and are marked in square brackets. Results of VIT were described in 117 patients to date. The mean rate of side-effects during treatment in studies published so far is 23.9% (7.6% requiring adrenaline) with an overall protection rate of 72%. Based on the review we conclude that (1) mastocytosis patients have a high risk of severe sting reactions in particular to yellow jacket, (2) VIT could be suggested [2] in mastocytosis, (3) probably should be done life long [2], (4) VIT in mastocytosis is accompanied by a higher frequency of side-effects, so (5) special precautions should be taken into account notably during the built up phase of the therapy [2], (6) VIT is able to reduce systemic reactions, but to a lesser extent compared to the general insect venom allergic population [2], so (7) patients should be warned that the efficacy of VIT might be less than optimal and they should continue carrying two adrenaline auto injectors [2].

The problem of anaphylaxis and mastocytosis

Mastocytosis is a rare disease characterized by an elevated whole body mast cell number. Anaphylaxis is a severe, generalized hypersensitivity reaction with rapid onset. The problem of anaphylaxis and mastocytosis is due to strongly increased mediator release from the elevated mast cell number during allergic reactions. This explains the much higher prevalence of anaphylaxis in mastocytosis than in the general population and its severe and sometimes fatal course. Because of the increased risk of anaphylaxis in mastocytosis, all patients with severe or recurrent anaphylaxis should be analyzed for underlying mastocytosis by estimation of baseline serum tryptase. If this is elevated, patients also should be tested via skin examination for cutaneous mastocytosis and with a bone marrow biopsy. All patients with mastocytosis and anaphylaxis must be instructed about avoiding the responsible elicitors and should carry an emergency kit with adrenaline for self-application. In mastocytosis patients with anaphylaxis due to Hymenoptera stings, venom immunotherapy is recommended for life.

Cutaneous manifestations in Hymenoptera and Diptera anaphylaxis: relationship with basal serum tryptase

OBJECTIVES

To compare the clinical presentation of systemic anaphylaxis to Hymenoptera and Diptera with regard to basal serum tryptase (BT) and to evaluate mastocytosis in patients with elevated tryptase.

PATIENTS AND METHODS

The medical records of 140 patients with a history of a systemic reaction to venom were retrospectively reviewed. Symptoms and severity of anaphylaxis and BT were recorded. Most patients with elevated tryptase were screened for mastocytosis: a dermatological examination with a skin biopsy was performed in 19 cases and a bone marrow biopsy in 14 cases.

RESULTS

Tryptase was elevated in 23 patients. These patients reported fewer usual skin reactions (urticaria in 26.1% of cases with raised tryptase vs. 76.1% of cases with normal tryptase), more flushing (52.2% vs. 4.3%) and frequently did not present skin reaction (26.1% vs. 9.4%). They presented a more severe reaction (mean grade of severity: 3.48 vs. 2.69). Mastocytosis was diagnosed in seven patients with elevated tryptase: indolent systemic mastocytosis in six cases and cutaneous mastocytosis without systemic involvement in one case. In five cases, mastocytosis was previously undiagnosed. Lesions of cutaneous mastocytosis, diagnosed in five patients, consisted of urticaria pigmentosa in all cases and were often inconspicuous.

CONCLUSION

These results demonstrate particular clinical features of the allergic reaction in patients with elevated BT and the higher frequency of mastocytosis in this population. In patients with a severe anaphylactic reaction without urticaria, but with flushing, tryptase should be assayed and an underlying mastocytosis should be considered.

Exercise-induced hypersensitivity syndromes in recreational and competitive athletes: a PRACTALL consensus report (what the general practitioner should know about sports and allergy)

Exercise-induced (EI) hypersensitivity disorders are significant problems for both recreational and competitive athletes. These include EI-asthma, EI-bronchoconstriction, EI-rhinitis, EI-anaphylaxis and EI-urticaria. A group of experts from the European Academy of Allergology and Clinical Immunology and the American Academy of Allergy Asthma and Immunology met to discuss the pathogenesis of these disorders and how to diagnose and treat them, and then to develop a consensus report. Key words (exercise with asthma, bronchoconstriction, rhinitis, urticaria or anaphylaxis) were used to search Medline, the Cochrane database and related websites through February 2008 to obtain pertinent information which, along with personal reference databases and institutional experience with these disorders, were used to develop this report. The goal is to provide physicians with guidance in the diagnosis, understanding and management of EI-hypersensitivity disorders to enable their patients to safely return to exercise-related activities.

Anaphylaxis in patients with mastocytosis: a study on history, clinical features and risk factors in 120 patients

BACKGROUND

Excessive mast cell mediator release may lead to anaphylaxis in patients with mastocytosis. However, the incidence, clinical features and trigger factors have not yet been analyzed.

METHODS

To identify risk factors for anaphylaxis in mastocytosis, we determined cumulative incidence, severity, clinical characteristics, and trigger factors for anaphylaxis in 120 consecutive patients (53 male; 67 female, median age and range 24 years, 1 month to 73 years), and correlated these with disease severity of mastocytosis, skin involvement, basal total serum tryptase, and diaminooxidase concentrations.

RESULTS

The cumulative incidence of anaphylaxis in patients with mastocytosis was higher in adults (49%; P < 0.01) compared with that in children (9%). Only children with extensive skin involvement had experienced anaphylaxis. In adults, anaphylaxis was correlated to the absence of urticaria pigmentosa lesions (P < 0.03). Reactions occurred more frequently in adults with systemic (56%) when compared with cutaneous mastocytosis (13%; P < 0.02). In adults, 48% of reactions were severe, and 38% resulted in unconsciousness. Major perceived trigger factors for adults were hymenoptera stings (19%), foods (16%), and medication (9%); however, in 26% of reactions, only a combination of different triggers preceded anaphylaxis. Trigger factors remained unidentified in 67% of reactions in children compared with 13% in adults. Patients with anaphylaxis had higher basal tryptase values (60.2 +/- 55 ng/ml, P < 0.0001) in comparison with those without (21.2 +/- 33 ng/ml), but not diaminooxidase levels.

CONCLUSION

Adult patients and children with extensive skin disease with mastocytosis have an increased risk to develop severe anaphylaxis; thus, an emergency set of medication including epinephrine is recommended.

Mastocytosis and allergy

PURPOSE OF REVIEW

To illustrate features of allergy in mastocytosis.

RECENT FINDINGS

The rates of atopy in patients with mastocytosis have generally been found to be similar to those of the normal population, although the incidence of anaphylaxis is much higher in mastocytosis. Introduction of objective pathologic criteria by the WHO for the diagnosis of mastocytosis has greatly facilitated the workup of patients with suspected mastocytosis, and has led to identification of mast cell disease in a subset of patients with anaphylaxis. There is increasing evidence that an activating c-kit mutation (D816V) exists in a subset of patients with recurrent mast cell activation symptoms who have normal-appearing bone marrow biopsies in routine evaluations without skin lesions. The genetic deficiency of alpha tryptase has not been found to influence serum tryptase levels in patients with mastocytosis.

SUMMARY

Pathologic mast cell activation is a key finding in both allergic diseases and mastocytosis, albeit caused by entirely different mechanisms. Mastocytosis should be suspected in patients with recurrent anaphylaxis, who present with syncopal or near-syncopal episodes without associated hives or angioedema.

Cardiovascular disease and anaphylaxis

PURPOSE OF REVIEW

In severe anaphylaxis, the cardiovascular system is often heavily involved. Preexisting cardiovascular disease may therefore influence the course of anaphylaxis in a negative way.

RECENT FINDINGS

Systemic mastocytosis and elevated baseline serum tryptase are associated with severe and fatal anaphylaxis to hymenoptera stings. This is due to an increased number of cardiac mast cells resulting in high concentrations of cardiotoxic mast cell mediators in cardiac tissue during anaphylaxis. Severe anaphylaxis in coronary heart disease, in particular, is explained by an increased load of cardiac mast cells together with coronary stenosis favouring myocardial hypoxia. Contraindications for the use of medications for cardiac disease in patients with anaphylaxis, especially beta-blockers, have been questioned by epidemiologic studies considering the positive effects of these drugs on much more prevalent cardiac diseases.

SUMMARY

Preexisting cardiovascular disease, mastocytosis and elevated baseline serum tryptase are risk factors for fatal anaphylactic reactions or lasting morbidity due to myocardial or cerebrovascular infarction induced by anaphylaxis. Life-saving cardiac medications like beta-blockers may increase the severity of anaphylaxis. Since life-threatening cardiovascular diseases are much more frequent than anaphylaxis, the relative risk of either disease with and without these drugs must be analyzed carefully together with the cardiologist.