Anaphylaxis: first clinical presentation, subsequent referral practise, and suspected elicitor-an observational study.

Anaphylaxis is an allergic manifestation characterised by rapid onset and progression. Rapid treatment may be challenging in patients with atypical symptoms or no previous history of anaphylaxis. This study aimed to describe the clinical prehospital presentation of first-time anaphylactic patients. To help target educational initiatives, we sought to identify which groups of medical professionals are most likely to encounter first-time anaphylactic patients and investigated the referral pattern for suspected anaphylactic patients for specialised treatment. A retrospective register-based study from the Region of Southern Denmark. Patients referred to the Allergy Centre, Odense University Hospital, from 2019 to 2021 were included. The medical records were manually reviewed for first contact with the emergency departments or the emergency medical service. 444 patients with suspected anaphylaxis were referred. 226 patients had grade 3-5 systemic allergic reactions as classified by the World Allergy Organisation; 90% had cutaneous symptoms, 63% symptoms from the central nervous system, 42% gastrointestinal symptoms, 40% cardiovascular symptoms, 36% had upper-airway symptoms, and 36% had lower-airway symptoms. Patients treated prehospitally had a significantly more severe degree of anaphylaxis than patients only treated within the hospital. More than half of the patients with suspected anaphylaxis were referred to the Allergy Centre from the emergency departments. Patients with allergies progressing to severe anaphylaxis most often are treated prehospitally before transport to emergency departments. From the emergency departments, they are referred to the allergy centre. Education concerning the immediate treatment of severe anaphylaxis should primarily be targeted towards prehospital care providers.

A comparison of double-blind, placebo-controlled food challenge and open food challenge.

BACKGROUND: Double-blind, placebo-controlled food challenge (DBPCFC) remains the gold standard for diagnosing food allergy, despite sparse comparisons to open food challenges (OpenFCs). The objective of this retrospective study was to compare severity of symptoms and threshold values (cumulative dose of food allergen eliciting a clinical reaction) in children and adults with peanut allergy, challenged in an open and/or double-blind, placebo-controlled protocol. METHODS: This study included patients from the Allergy Centre, Odense University Hospital with a positive oral food challenge, defined as strict objective signs, with peanut during the period 2001-2022. Severity of symptoms was graded using the Sampson's severity score. Distribution models of threshold values were calculated using log-normal interval-censored survival analysis, and the number of placebo reactions was evaluated. RESULTS: In total, 318 positive OpenFCs and 86 DBPCFCs were included. There was no difference in severity of symptoms nor threshold values comparing the two challenge types, neither when stratified for age groups. However, a higher proportion of children experienced Grade 3 symptoms in the double-blind group. Only one patient had a positive reaction to a placebo challenge. CONCLUSION: Our findings do not advocate for DBPCFC being superior to OpenFC, if the latter is performed with strict objective stop criteria by trained staff.