Anisakis, Something Is Moving inside the Fish.

The first case of human infection by a species of the Anisakidae family was reported more than 60 years ago. Over the last 20 years, Anisakis has become a highly studied parasite, not only for its parasitism, but also for its role as an inducer of allergic reactions. Several studies have indicated that the pathological changes occurring within the gastrointestinal tract during infection with Anisakis simplex are the combined result of the direct action of the larvae invading the tissue and the complex interaction between the host's immune system and the parasite. Although the most commonly described pathologies are digestive, urticaria/angioedema and anaphylaxis, occupational asthma and arthritis have been seldom described. This paper is a narrative of the immune-mediated reaction induced by this parasite over the course of the last two decades.

Evidence of IgE-Mediated Cross-Reactions between Anisakis simplex and Contracaecum osculatum Proteins.

Fish consumers may develop allergic reactions following the ingestion of fish products containing nematode larvae within the genus Anisakis. Sensitized patients may cross-react with proteins from insects, mites and mollusks, leading to allergic reactions even in the absence of the offending food. Potential cross-reactivity in Anisakis-allergic patients with larval proteins from other zoonotic parasites present in freshwater and sea fish should be investigated due to an increasing occurrence in certain fish stocks, particularly Contracaecum osculatum. In this work, we evaluated IgE-cross reactions by in vivo (skin prick tests with parasites extracts) and in vitro methods (IgE-ELISA and IgE-immunoblot). In vivo skin prick tests (SPT) proved the reactivity of Anisakis-sensitized patients when exposed to C. osculatum antigens. Sera from Anisakis-sensitized patients confirmed the reaction with somatic antigens (SA) and excretory/secretory proteins (ES) from C. osculatum. Only anecdotal responses were obtained from other freshwater worm parasites. Consequently, it is suggested that Anisakis-sensitized humans, especially patients with high levels of specific anti-Anisakis antibodies, may react to C. osculatum proteins, possibly due to IgE-mediated cross-reactivity.

Prospective assessment of diagnostic tests for pediatric penicillin allergy: From clinical history to challenge tests.

BACKGROUND: Diagnostic guidelines for penicillin allergy in children recommend cumbersome protocols based partially on data from adults, which may be suboptimal for pediatric use. OBJECTIVE: To assess the accuracy of tools for diagnosis of penicillin allergy in children. METHODS: A prospective, multicenter study was conducted in children with reported adverse events related to penicillin, excluding severe reactions. All patients underwent a uniform diagnostic protocol that consisted of clinical history, skin tests, serum specific IgE (sIgE), and, regardless of these results, drug provocation tests (DPTs). RESULTS: A total of 732 children (mean age, 5.5 years; 51.2% males) completed the allergy workup, including DPTs. Amoxicillin triggered 96.9% of all reactions. None of the patients with an immediate index reaction (IR) developed a reaction on DPT. Penicillin allergy was confirmed in 35 children (4.8%): 6 immediate reactions (17%) and 29 nonimmediate reactions (83%) on the DPT. No severe reactions were recorded. The allergist diagnosis based on the clinical history was not associated with the DPT final outcome. In 30 of 33 allergic patients (91%), the results of all skin tests and sIgE tests were negative. A logistic regression model identified the following to be associated with penicillin allergy: a family history of drug allergy (odds ratio [OR], 3.03; 95% confidence interval [CI], 1.33-6.89; P = .008), an IR lasting more than 3 days vs 24 hours or less (OR, 8.96; 95% CI, 2.01-39.86; P = .004), and an IR treated with corticosteroids (OR, 2.68; 95% CI, 1.30-5.54; P = .007). CONCLUSION: Conventional predictors of allergy to penicillin performed weakly. The authors propose straightforward penicillin provocation testing in controlled, experienced centers for the diagnosis of nonsevere penicillin allergy in children.

Omalizumab efficacy in cases of chronic spontaneous urticaria is not explained by the inhibition of sera activity in effector cells.

Omalizumab (OmAb) is a humanized anti-IgE antibody approved for the treatment of chronic spontaneous urticaria (CSU). OmAb's mechanism of action is known to include actions on free IgE and on pre-bound IgE. However, OmAb is equally and rapidly effective against autoimmune and non-autoimmune urticaria where IgE involvement is not clear, suggesting the involvement of additional mechanisms of action. In this study, we sought to investigate the ability of OmAb to inhibit mast cell and basophil degranulation induced by sera from CSU patients. For this purpose, we performed a comparison between the in vitro incubation of sera from CSU patients treated with OmAb and the in vivo administration of OmAb in a clinical trial. We found that OmAb added in vitro to sera from CSU patients did not modify the ability of the sera to induce cell degranulation. Similarly, the sera from patients treated with OmAb in the context of the clinical trial who had a good clinical outcome maintained the capacity to activate mast cells and basophils. Thus, we conclude that the beneficial activity of OmAb does not correlate with the ability of patient sera to induce cell degranulation.

Allergic contact dermatitis from mercury antiseptics and derivatives: study protocol of tolerance to intramuscular injections of thimerosal.

BACKGROUND: Mercury derivatives are frequent contact allergens and their cross-reactivity is not constant. Thimerosal is an organic mercurial used as an antiseptic and as a preservative in most vaccines. OBJECTIVE: To evaluate cross-reactivity, exposure factors, and tolerance to vaccines containing thimerosal in patients sensitized to mercury derivatives. DESIGN: Observational study (cross-sectional); PATIENTS: 125 patients were recruited for the study, 72 women and girls and 53 boys and men, average age 18.7 years old, range 3 to 65, with positive patch tests to mercury derivatives and/or thimerosal; INTERVENTIONS: All patients were studied by means of enquiry, patch tests, intradermal tests, and intramuscular challenge with thimerosal. RESULTS: A sensitization to thimerosal was observed in 57 patients. Twenty-four of these 125 patients presented a positive intradermal reaction. Ammoniated mercury seems to be a good marker of mercury sensitization eliciting positive reaction in 78% of all patients and merbromin in 66%. In most cases, (100/125) cross-reactivity was found among mercury derivatives. The intramuscular injection of thimerosal induced a mild local reaction in only 5 patients (4% of the total, 9% of thimerosal positive reactions). Childhood vaccinations, merbromin used as an antiseptic, broken thermometers, and the use of drops were the main sources of exposure. CONCLUSIONS: The majority of the patients showed positive tests to both organic and inorganic mercury derivatives. Vaccination with thimerosal is relatively safe, even for individuals with delayed type hypersensitivity to this chemical, since more than 90% of allergic patients tolerated intramuscular challenge tests with thimerosal. A simplified protocol of patch tests to study mercury derivatives is proposed. It would be advisable to restrict the use of mercurial antiseptics and mercury thermometers.

Anisakis simplex: dangerous--dead and alive?

The risk of infection with Anisakis simplex and related parasites of fish has been recognized for some time, but it is now emerging that ingestion of material from dead parasites in food is also potentially dangerous. The resulting allergic reactions range from rapid onset and potentially lethal anaphylactic reactions to chronic, debilitating conditions. This review discusses the problems and clinical implications associated with A. simplex, other related conditions, and the way in which disease manifestations vary from person to person.