1. Home
  2. Allergic reactions

Allergic reactions

Tick-borne red meat allergy (α-gal syndrome)

Author/s: 
Jeimy, Samira, Zhu, Rongbo

Tick-borne red meat allergy occurs from sensitization to a carbohydrate, galactose-α-1,3-galactose (α-gal)

The lone star tick (Amblyomma americanum) is commonly found in the southern United States, but its prevalence in Canada is increasing.1 The tick’s saliva contains a high level of α-gal, a carbohydrate antigen also present in nonprimate mammalian cell membranes.2 Skin and bloodstream exposure to this antigen through a tick bite leads to sensitization to the carbohydrate and, subsequently, to red meat allergy.

Keywords 
tick-borne illness Allergic reactions red meat allery

Infant pacifier sanitization and risk of challenge-proven food allergy: A cohort study

Author/s: 
Soriano, V.X., Koplin, J.J., Forrester, M., Peters, R.L., O'Hely, M., Dharmage, S.C., Wright, R., Ranaganathan, S., Burgner, D., Thompson, K., Dwyer, T., Vuilerman, P., Ponsonby, A.

Background: Environmental microbial exposure plays a role in immune system development and susceptibility to food allergy.

Objective: We sought to investigate whether infant pacifier use during the first postnatal year, with further consideration of sanitization, alters the risk of food allergy by age 1 year.

Methods: The birth cohort recruited pregnant mothers at under 28 weeks' gestation in southeast Australia, with 894 families followed up when infants turned 1 year. Infants were excluded if born under 32 weeks, with a serious illness, major congenital malformation, or genetic disease. Questionnaire data, collected at recruitment and infant ages 1, 6, and 12 months, included pacifier use and pacifier sanitization (defined as the joint exposure of a pacifier and cleaning methods). Challenge-proven food allergy was assessed at 12 months.

Results: Any pacifier use at 6 months was associated with food allergy (adjusted odds ratio, 1.94; 95% CI, 1.04-3.61), but not pacifier use at other ages. This overall association was driven by the joint exposure of pacifier-antiseptic use (adjusted odds ratio, 4.83; 95% CI, 1.10-21.18) compared with no pacifier use. Using pacifiers without antiseptic at 6 months was not associated with food allergy. Among pacifier users, antiseptic cleaning was still associated with food allergy (adjusted odds ratio, 3.56; 95% CI, 1.18-10.77) compared with no antiseptic use. Furthermore, persistent and repeated antiseptic use over the first 6 months was associated with higher food allergy risk (P = .029).

Conclusions: This is the first report of a pacifier-antiseptic combination being associated with a higher risk of subsequent food allergy. Future work should investigate underlying biological pathways.

Keywords: Pacifier; antiseptic; birth cohort; dummy; food allergy; microbial exposure; sanitization.

Keywords 
infant Pregnancy Pregnant Persons Mothers Allergic reactions Food Allergies

Allergic Reactions Including Anaphylaxis After Receipt of the First Dose of Pfizer-BioNTech COVID-19 Vaccine

Author/s: 
Shimabukuro, T., Nair, N.

On December 11, 2020, the US Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for the Pfizer-BioNTech coronavirus disease 2019 (COVID-19) vaccine, administered as 2 doses separated by 21 days.1 Shortly after, the Advisory Committee on Immunization Practices (ACIP) issued an interim recommendation for its use.2 Following implementation of vaccination, reports of anaphylaxis after the first dose of the Pfizer-BioNTech COVID-19 vaccine emerged.3 Anaphylaxis is a life-threatening allergic reaction that occurs rarely after vaccination, with onset typically within minutes to hours.4

Notifications and reports of suspected severe allergic reactions and anaphylaxis following vaccination were captured in the Vaccine Adverse Event Reporting System (VAERS), the national passive surveillance (spontaneous reporting) system for adverse events after immunization.5 Physicians at the US Centers for Disease Control and Prevention (CDC) evaluated these reports and applied Brighton Collaboration case definition criteria6 to classify case reports as anaphylaxis or not anaphylaxis. Nonallergic adverse events, mostly vasovagal or anxiety-related, were excluded from the analysis. Anaphylaxis and nonanaphylaxis allergic reaction cases with symptom onset occurring later than the day after vaccination were also excluded because of the difficulty in clearly attributing allergic reactions with delayed onset after vaccination. Because the Moderna COVID-19 vaccine was only available beginning December 21, 2020, this article focuses on the Pfizer-BioNTech COVID-19 vaccine.

During December 14 to 23, 2020, after administration of a reported 1 893 360 first doses of Pfizer-BioNTech COVID-19 vaccine (1 177 527 in women, 648 327 in men, and 67 506 with sex of recipient not reported),3 CDC identified 21 case reports submitted to VAERS that met Brighton Collaboration case definition criteria for anaphylaxis (Table), corresponding to an estimated rate of 11.1 cases per million doses administered. Four patients (19%) were hospitalized (including 3 in intensive care), and 17 (81%) were treated in an emergency department; 20 (95%) are known to have been discharged home or had recovered at the time of the report to VAERS. No deaths from anaphylaxis were reported.

Keywords 
COVID-19 COVID-19 vaccine coronavirus vaccines Pfizer Pfizer–BioNTech mRNA vaccine Anaphylaxis Allergic reactions
Subscribe to Allergic reactions