An Unusual IgE-Mediated Hypersensitivity: Two Case Reports of Paracetamol Allergy.

Paracetamol is one of the most commonly used analgesic and antipyretic agents worldwide, attributed in part to its excellent safety profile when administered at recommended doses. Paracetamol allergy is not common, and the majority of the reactions are related to the pharmacological action of cyclooxygenase 1 inhibition. Selective and Immunoglobulin E (IgE)-mediated hypersensitivity reactions are rare. In this article, the authors report two cases of paracetamol allergy in which the mechanism of IgE-mediated hypersensitivity was demonstrated by positive skin tests and basophil activation tests. We highlight the relevance of identifying the mechanism underlying the reaction since patients with IgE-mediated paracetamol allergies will be able to tolerate non-steroidal anti-inflammatory drugs.

Chlorhexidine: a hidden life-threatening allergen.

Chlorhexidine is a commonly used antiseptic and disinfectant in the health-care setting. Anaphylaxis to chlorhexidine is a rare but potentially life-threatening complication. Epidemiologic data suggest that the cases of chlorhexidine allergy appears to be increasing. In this article we report a life-threatening anaphylactic shock with cardiorespiratory arrest, during urethral catheterization due to chlorhexidine. The authors also performed a literature review of PubMed library of anaphylactic cases reports due to this antiseptic between 2014 and 2018, demonstrating the increase in the number of cases occurring worldwide and the importance of detailed anamnesis and appropriate diagnostic workup of allergic reactions to disinfectants.

Clinical, anamnestic and serological features of peach allergy in portugal.

BACKGROUND: Peach is a common food allergen source throughout Europe. The aim of this study was to characterize peach allergy in a Portuguese patient population. METHODS: Thirty peach-allergic patients confirmed by double-blind placebo-controlled food challenges and 29 controls were included. All subjects completed a standardized questionnaire regarding symptoms and epidemiologic characteristics, skin prick tests with inhalant allergens and foods as well as specific IgE antibodies to peach, recombinant peach allergens rPru p 1, rPru p 3, rPru p 4 and cross-reactive carbohydrate determinants. RESULTS: Thirty-seven percent of patients reported only oral allergy syndrome, while 37% reported generalized urticaria and/or angioedema, 17% localized contact urticaria and 10% anaphylaxis with peach. Sensitization to other Rosaceae fruits and tree nuts was present in 90 and 77% of the patients, respectively. Respiratory allergy history was associated with less severe symptoms (oral allergy syndrome or contact urticaria; p < 0.01) and positive skin prick test to peach peel or plum with more severe symptoms (urticaria and/or angioedema or anaphylaxis; p < 0.05). Ninety-seven percent were sensitized to Pru p 3, 13% to Pru p 4, 3% to Pru p 1 and 10% to cross-reactive carbohydrate determinants. Pru p 3 specific IgE was associated with Artemisia vulgaris sensitization and tree nut allergy (p < 0.05) but not with clinical severity. CONCLUSIONS: Half the patients reported systemic reactions to peach. Peach allergy appeared predominantly mediated by Pru p 3 but some patients were sensitized to Pru p 4. Applying a 0.10 kU(A)/l cutoff level, the diagnostic value of combining the 3 recombinant allergens was noteworthy, with 100% sensitivity and 90% specificity.