TOPLINE

Anaphylaxis in infants and young toddlers presents with age-specific symptoms — pallor, hypotonia, persistent crying — that differ from older children, complicating timely recognition, with cardiovascular signs predicting those at risk for a second anaphylactic reaction.

METHODOLOGY

• Researchers conducted a retrospective analysis to characterize symptom patterns and management of anaphylaxis in children aged 0-2 years in an Australian cohort presenting to a tertiary pediatric emergency department (ED) over two 5-year periods (2003-2007 and 2013-2017).
• A total of 243 confirmed anaphylaxis cases were identified among infants aged 0-2 years; 72 cases occurred in 2003-2007 (27.8% female) and 171 in 2013-2017 (39.2% female).
• Anaphylaxis was defined according to Australasian Society for Clinical Immunology and Allergy criteria, and severity was graded using the European Academy of Allergy and Clinical Immunology classification.
• Biphasic anaphylaxis was defined as one or more anaphylactic symptoms occurring 1-48 hours after complete resolution of initial symptoms without re-exposure to the allergen.

TAKEAWAY

• Mucocutaneous symptoms were the most common presentation (95.8%) among infants presenting with anaphylaxis, followed by respiratory (81.6%), gastrointestinal (43.1%), cardiovascular (33.9%), and neurologic symptoms (18.8%).
• Biphasic anaphylaxis occurred in 4.6% of cases, with most requiring ward admission; biphasic reactors were generally younger than uniphasic cases (median 7.0 months vs 10 months; P = .048). All biphasic anaphylaxis cases were food-induced, with cooked egg being the most frequently implicated allergen (4 of 11 cases).
• When uniphasic and biphasic cases were compared with respect to the primary reaction, biphasic reactors more often showed cardiovascular signs such as pallor/hypotonia (P = .048) and reduced systolic blood pressure (P = .011); these reactors also experienced more severe anaphylaxis (P = .014).
• On presentation to the ED, symptom resolution was less frequent in biphasic than in uniphasic cases (P = .026). The use of oxygen, steroids, and intravenous fluids (P < .05 for all) was significantly higher in biphasic than uniphasic cases.

IN PRACTICE

"While a 4-hour observation period seems sufficient for most infants/toddlers experiencing anaphylaxis, greater severity, cardiovascular signs and/or fluid resuscitation may be useful predictors of biphasic/recurrent anaphylaxis in 0-2-year-olds. Hence, infants/young toddlers presenting with these signs may benefit from an extended (>4 h) inpatient observation time," the authors wrote.

SOURCE

The study was led by Kristina Rueter, Perth Children's Hospital, Nedlands, Australia. It was published online on August 19 in Pediatric Allergy and Immunology.

LIMITATIONS

The study was retrospective in nature and may have incomplete data and reporting bias. The small number of biphasic cases limits robust analysis for identifying predictors. Biphasic reactions occurring post-discharge may have been missed, potentially underestimating the true incidence.

DISCLOSURES

No specific funding was reported. The authors reported no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.