Focus on the role of substance P in chronic urticaria.

BACKGROUND: Emerging data have strengthened the importance of substance P (SP) as a proinflammatory mediator in human pathology. A role for SP in the pathogenesis of urticaria has long been hypothesized. METHODS: Literature data regarding the possible role of SP in chronic urticaria/chronic spontaneous urticaria (CSU) have been reviewed and summarized in this manuscript. This review is based on pertinent articles that were retrieved by a selective literature search in the PubMed database. Articles in English published up to July 2018 were taken into consideration. RESULTS: Recent studies in patients with CSU have demonstrated that circulating levels of SP are significantly elevated, in correlation with disease severity, and that SP-positive basophils are upregulated. SP has been shown to trigger degranulation in basophils derived from CSU patients. Moreover, SP can be involved in pseudoallergic reactions and may act as a histamine-releasing factor in a subset of patients with CSU. Current evidence suggests that the biological activity of SP can be exerted not only through the conventional NK-1 receptor but also through the recently identified Mas-related G protein-coupled receptors. MRGPRX2 can cause mast cell activation and has been found to be upregulated in the skin of patients with severe chronic urticaria. CONCLUSIONS: Many findings seem to support the pathogenic involvement of SP in chronic urticaria/CSU. However, further studies are necessary to elucidate the role of SP as a mediator in CSU pathogenesis and a potential new therapeutic target.

Focus on the agents most frequently responsible for perioperative anaphylaxis.

Adverse reactions (ARs) to drugs administered during general anesthesia may be very severe and life-threatening, with a mortality rate ranging from 3 to 9%. The adverse reactions to drugs may be IgE and non-IgE-mediated. Neuromuscular blocking agents (NMBA) represent the first cause of perioperative reactions during general anesthesia followed by latex, antibiotics, hypnotic agents, opioids, colloids, dyes and antiseptics (chlorhexidine). All these substances (i.e. NMBA, anesthetics, antibiotics, latex devices) may cause severe systemic non-IgE-mediated reactions or fatal anaphylactic events even in the absence of any evident risk factor in the patient's anamnesis. For this reason, in order to minimize perioperative anaphylactic reactions, it is important to have rapid, specific, sensitive in vitro diagnostic tests able to confirm the clinical diagnosis of acute anaphylaxis.

Immediate-type hypersensitivity reaction to Mannitol as drug excipient (E421): a case report.

Allergic reactions to mannitol have been reported rarely, despite its widespread use as a drug and as a food excipient. This is the first case report in which oral mannitol induces an immediate type hypersensitivity as a drug excipient, in a 42 year old man affected by rhinitis to olive tree pollen. Unusual and undervalued risk factors for mannitol hypersensitivity are examined.

Diagnosis of latex allergy: the importance of hev B 11.

We present the cases of 5 patients with a positive clinical history of cutaneous symptoms due to contact with latex products. A latex allergological assessment was made through skin prick tests (SPTs) both with commercial latex extracts and extemporaneous glove extracts, and serum-specific IgE to latex and glove-use tests. In addition, serum-specific IgE to recombinant allergens for Hevea brasiliensis was dosed. Molecular diagnostics in association with the glove-use test and, to a lesser extent, the SPTs with glove eluate are useful diagnostic tests to confirm the diagnosis of latex allergy in patients with mucocutaneous symptoms.

Anaphylaxis induced by intramuscular betamethasone disodium phosphate: reflections on a clinical case.

Glucocorticoids could be responsible for allergic symptoms correlated to an Ig-E mediated hypersensitivity mechanism. We describe the case of an anaphylactic reaction in a professional nurse, occurring after an intramuscular administration of Betamethasone. After performing skin prick tests, intramuscular tests and patch tests we concluded that the patient had Ig-E mediated sensitization. She was prescribed oral Prednisone and Deflazacort and shows good tolerance of these drugs. This demonstrates that in these patients it is possible to administrate glucocorticoids without the changes in the sites indicated by Wilkinson. Nevertheless, our patient showed a negative allergy test for Dexamethasone disodium phosphate, and in those patients sensitized to fluorinated glucocorticoids, tolerance to other glucocorticoids is not so easily predictable as in patients with hypersensitivity to first generation steroids or in corticosteroid contact dermatitis, according to the four patterns of cross-reactivity proposed by Coopman and Dooms-Goossens.

A joint allergist/cardiologist classification for thienopyridines hypersensitivity reactions based on their symptomatic patterns and its impact on the management strategies.

The role and importance of thienopyridines such as ticlopidine, clopidogrel, and prasugrel is well-established for several indications, ranging from prevention of acute coronary syndromes to percutaneous coronary interventions, where the dual antiplatelet therapy represents the gold standard to avoid denovo coronary stenosis. However, there is a significant cohort of patients with coronary artery disease who may manifest hypersensitivity reactions to thienopyridines. The examination of the various case reports from medical literature leads to identify mainly four clinical patterns of hypersensitivity to thienopyridines which involves more frequently cutaneous, hematologic, and articular tissues, therefore the kind and predominance of clinical symptoms may determine a different clinical approach to overcome or neutralize thienopyridines hypersensitivity.

Allergic and pseudoallergic reactions induced by glucocorticoids: a review.

Glucocorticoids (GCs) represent the most effective treatment for autoimmune and allergic diseases, even if collateral effects are not rare, especially endocrine and immunosuppressive manifestations. Moreover, these drugs can develop adverse immunological reactions of I, III or IV type. Though immediate adverse reactions caused by systemic therapy with GCs are not very frequent, the possible beginning of anaphylactic and pseudo-anaphylactic manifestations in patients undergoing therapy with these drugs has to be considered. It has been observed that immediate adverse reactions usually are happened in asthmatic patients and in patients obliged to assume GCs again and again because of their pathology (e.g, kidney transplant). Other risk factors resulted to be female sex and hypersensibility to acetylsalicylic acid (ASA). Both in the cases of pseudo-allergic and allergic reactions, the pharmacological principle is hardly the responsible agent for the reaction; instead the excipients in drugs are often implicated (succinate salt, sulphites and carboxy-methyl-cellulose). It is possible that the IgE-response is highly specific for a fixed GC molecule as well depending on the way of administration and its salification. Moreover, it has been hypothesized that in patients with a first type allergic reaction to GCs there is a fourth type, sensitization to GCs, which is not usually diagnosed and even comes before IgE sensitization. Third type hypersensibility reactions may occur, too. Since GCs are large-scale drugs, also in emergency medicine and reanimation, allergic sensitization towards them, although infrequent, gives many interventionist problems. In the light of this feature, it seems of crucial importance to verify the tolerance toward other GC molecules. And in particular, it has been noted that patients presenting immediate reactions to hydrocortisone (HC) and methylprednisolone (MP) could tolerate prednisone and prednisolone per os and second-generation GCs, such as desamathazone and betamethazone. Nevertheless, second-generation GCs must not be considered safe; in fact, the beginning of allergic manifestations has been pointed out even towards them.

Once daily levocetirizine for the treatment of allergic rhinitis and chronic idiopathic urticaria.

Levocetirizine is the pharmacologically active enantiomer of cetirizine. It is a potent histamine H-1 receptor antagonist with anti-inflammatory and antiallergic properties. The review analyses the levocetirizine's properties in terms of safety and efficacy both in allergic rhinitis and urticarioid syndromes.

Allergic reactions to inhalant glucocorticosteroids: a hot topic for pneumologists and allergologists.

Allergic contact dermatitis to topical glucocorticosteroids (GCS) is a delayed type cell-mediated hypersensitivity reaction; it is frequently observed in dermatological and allergological practice, although its incidence is likely underestimated. By contrast, allergic contact sensitization to inhalant GCS is virtually unknown to most pneumologists. Here, we review some cases of adverse reactions to inhalant GCS in terms of pathogenetic mechanisms, risk factors, epidemiology, and allergic cross-sensitivity. In fact, this particular form of sensitization to drugs that have a wide spectrum of use in pneumological practice deserves more attention than in the past.

Cross-reactivity in cell-mediated and IgE-mediated hypersensitivity to glucocorticoids.

In the last few decades, glucocorticoids have received increasing attention for their capability of provoking systemic hypersensitivity reactions, when administered orally, parenterally, or intralesionally, as well as allergic skin and mucosal symptoms, when applied locally to the skin in patients with contact dermatitis or to the mucosa in patients with asthma and/or rhinitis. However, because of their anti-inflammatory and immunosuppressive properties, glucocorticoids are often not suspected of such hypersensitivity reactions. In addition, because glucocorticoids retain their anti-inflammatory potential, even if they act as sensitizers, the signs and symptoms of allergic reactions are not always obvious, particularly when they overlap with those caused by the very diseases glucocorticoids are used to treat. Moreover, interpretation of diagnostic tests, specifically that of patch-test reactions, can be difficult. In this review, particular attention is addressed to the problem of allergenic cross-reactivity among topical and systemic glucocorticoids. We also look at the clinical and practical aspects of both cell-mediated and IgE-mediated hypersensitivity reactions to glucocorticoids and their consequences on anti-inflammatory therapeutic choices.

Alternative glucocorticoids for use in cases of adverse reaction to systemic glucocorticoids: a study on 10 patients.

BACKGROUND: Reactions to systemically administered corticosteroids are rare, despite their widespread use. OBJECTIVES: To identify alternative glucocorticoids for emergency use in patients with adverse reactions to systemic glucocorticoids. METHODS: Ten patients were identified as having adverse reactions after the use of systemic corticosteroids. Skin prick tests and intradermal tests to hydrocortisone (HC) and methylprednisolone (MP), and intradermal tests to betamethasone and dexamethasone, were performed in all patients, and oral challenge tests to betamethasone (n=10) and deflazacort (n=6). RESULTS: Skin prick tests were negative in all patients, whereas intradermal tests to HC and MP were positive in eight; two patients showed only an isolated cutaneous sensitivity to MP. Intradermal tests to betamethasone and dexamethasone were negative, and oral challenge tests were negative in all patients. CONCLUSIONS: Our results suggest the possibility of an IgE-mediated mechanism for allergic reactions to HC and MP, probably due, at least in part, to a steroid-glyoxal. We suggest that betamethasone and deflazacort could be reserved for emergency use in patients with adverse reactions to other corticosteroids.

Long-term selective IgE-mediated hypersensitivity to hydrocortisone sodium succinate

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