ABSTRACT
Peanut allergy is one of the most common food allergies in childhood. In vitro cross-sensitization between peanut and tree nuts (TN) is high, but only a subgroup of patients allergic to peanut will have a concomitant allergy to one or several TN. In this article, the authors report a case of a 12-year-old boy who experienced 1 episode of lips and mouth itching, generalized urticarial, and eyelid angioedema 20 minutes after ingestion of peanut at 4 years of age. The immunoallergological study revealed the presence of a concomitant allergy to peanut, pistachio, and cashew confirmed with medically supervised oral food challenges (OFC) in a child who had never eaten these TN. The mechanism of IgE-mediated hypersensitivity was demonstrated by positive skin prick tests (SPT) with commercial extracts, although the specific IgE (sIgE) for these foods was negative. As described in the literature, we concluded that serum peanut and TN sIgE measurements have lower sensitivity than SPT to assess IgE sensitization, and OFC is the gold standard for accurate diagnosis of food allergy. We highlight the relevance of excluding or confirming TN allergy in a peanut-allergic patient who had never ingested certain TN, and of knowing the clinical relevant cross-reactivity patterns between TN, pistachio/cashew, and walnut/pecan, that could reduce the need for OFC in clinical practice, reducing allergy rates and financial and health burdens of food allergy.
ABSTRACT
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.
ABSTRACT
BACKGROUND: Data on real-life experience with omalizumab dose/interval adjustments are still limited, as well as on omalizumab discontinuation. OBJECTIVE: To evaluate efficacy and safety of omalizumab dose/interval adjustment in a Portuguese cohort of patients with chronic spontaneous urticaria (CSU) and to characterize those who discontinued omalizumab. METHODS: A retrospective study of patients who started omalizumab for CSU at a Portuguese Urticaria Center of Reference and Excellence (UCARE) was conducted between 2009 and 2021. Response criteria were based on a weekly Urticaria Activity Score (UAS7) <7 points (partial: UAS7 7-15 points; nonresponders: UAS7 >15 points) and minimal important difference >10 points. RESULTS: A total of 138 patients were enrolled in the study; 83% of them were women, and the median age was 49 years (interquartile range: 40-58 years). On 300 mg q4 weeks, 96 (70%) patients were responders, 29 (21%) partial responders, and 13 (9%) nonresponders. After dose/interval adjustments (up to 600 mg q2 weeks), 108 (78%) were responders, 27 (20%) partial responders, and 3 (2%) nonresponders. No adverse events were reported. Updosing was more frequent in patients with angioedema, body mass index >30 kg/m2, positive basophil activation test, and autologous serum test. A total of 71 (51%) patients lengthened interval, presenting higher median pre-omalizumab D-dimer (0.2 vs 0 mcg/mL, P = .038) and C-reactive protein (0.3 vs 0.1 mg/dL, P = .030) values than those with a standard dose. In total, 37 patients (27%) stopped omalizumab, but 14 (38%) of them needed retreatment on average 11 months after discontinuation. Patients with angioedema and a longer omalizumab duration had higher chance of relapse. CONCLUSIONS: Omalizumab dose and/or interval adjustment is effective and safe and should be implemented in partial/nonresponders for response improvement and in responders for further discontinuation. A protocol for regimen adjustments is proposed.
