Food allergy-induced anaphylaxis rates increase among infants in Australia

Although anaphylaxis rates among infants have increased, whether these increases are due to recommendations for earlier introduction of potential allergens is unclear, according to data published in Annals of Allergy, Asthma & Immunology.

Also, the use of adrenaline was sub-optimal in the anaphylaxis cases that were recorded, Sandra L. Vale, BSc, PhD student in the of the University of Western Australia School of Allied Health, and colleagues wrote.

In 2016, the Australasian Society of Clinical Immunology and Allergy (ASCIA) updated its Guidelines for infant feeding and allergy prevention to recommend that caregivers introduce infants to all common food allergens by age 12 months.

Launched in Western Australia in August 2018 and nationwide in June 2019, the Australian National Allergy Strategy’s Nip allergies in the Bub (NAITB) campaign was designed to promote these recommendations among caregivers and health professionals.

Hypothesizing that increased consumption of potential food allergens among infants would correspond with increases in anaphylaxis rates, the researchers examined data from the St. John Ambulance (SJA) service and from EDs in Western Australia from July 1, 2015, to June 30, 2020.

There were 172 infant anaphylaxis attendances in the SJA dataset and 294 in the ED dataset during the study period.

In the SJA dataset, monthly anaphylaxis rates increased from 5.8/10⁵ population in July 2015 to 9.45/10⁵ population in June 2020, with an overall increasing trend over time. These data equated to a 1-year increase rate ratio of 1.21 (95% CI, 1.09-1.35), or a 21% increase.

The ED dataset also revealed an overall increasing trend over time with a 1-year increase ratio of 1.11 (95% CI, 1.02-1.2), or 11%. The researchers called the patterns of event rates among the SJA and ED datasets similar.

Additionally, the researchers observed a level change upward for infant anaphylaxis rates in the SJA dataset when NAITB was launched, but they did not consider this change to be significant (RR = 1.74; 95% CI, 0.94-3.2). They also did not observe any slope change due to the intervention (RR = 1.01; 95% CI, 0.97-1.04).

The researchers did not observe any level change in the ED dataset due to the NAITB campaign (RR = 1.01; 95% CI, 0.63-1.64), although they did cite a nonsignificant upward slope change (RR = 1.01; 95% CI, 0.98-1.04).

Ambulance crews did not code for the administration of adrenaline in 63% of the anaphylaxis events. Also, ambulance crews administered adrenaline in 54 of the 63 events where adrenaline administration was recorded.

Adrenaline was administered before the crew arrived in 10 events, and in one of these events, the crew administered a second dose after they arrived. The ASCIA Action Plan recommends that the ambulance is called after adrenaline has been administered.

Despite these increases in rates of infant anaphylaxis, the researchers wrote, they were not directly attributable to the NAITB campaign. Instead, the researchers said these increases could be due to increased education and awareness as well as to improved policies and legislation addressing anaphylaxis management in the community.

The researchers also concluded that more parents are following current ASCIA Guidelines for introducing infants to potential allergens, although more research will be necessary to determine if these increases are attributable to the NAITB campaign or to general community awareness.

Further, the researchers called for the development of a program that would actively monitor allergic reactions among infants, including anaphylaxis, to foods during the first year of life.