Anaphylaxis: Unique aspects of clinical diagnosis and management in infants (birth to age 2 years)

Abstract

In this rostrum we aim to increase awareness of anaphylaxis in infancy in order to improve clinical diagnosis, management, and prevention of recurrences. Anaphylaxis is increasingly reported in this age group. Foods are the most common triggers. Presentation typically involves the skin (generalized urticaria), the respiratory tract (cough, wheeze, stridor, and dyspnea), and/or the gastrointestinal tract (persistent vomiting). Tryptase levels are seldom increased because of infant anaphylaxis, although baseline tryptase levels can be increased in the first few months of life, reflecting mast cell burden in the developing immune system. The differential diagnosis of infant anaphylaxis includes consideration of age-unique entities, such as food protein-induced enterocolitis syndrome with acute presentation. Epinephrine (adrenaline) treatment is underused in health care and community settings. No epinephrine autoinjectors contain an optimal dose for infants weighing 10 kg or less. After treatment of an anaphylactic episode, follow-up with a physician, preferably an allergy/immunology specialist, is important for confirmation of anaphylaxis triggers and prevention of recurrences through avoidance of confirmed specific triggers. Natural desensitization to milk and egg can occur. Future research should include validation of the clinical criteria for anaphylaxis diagnosis in infants, prospective longitudinal monitoring of baseline serum tryptase levels in healthy and atopic infants during the first year of life, studies of infant comorbidities and cofactors that increase the risk of severe anaphylaxis, development of autoinjectors containing a 0.1-mg epinephrine dose suitable for infants, and inclusion of infants in prospective studies of immune modulation to prevent anaphylaxis recurrences.

Keywords: Infants (birth to 2 years); adrenaline; antihistamines; clinical criteria for diagnosis; epinephrine; epinephrine autoinjectors; food allergy; food protein–induced enterocolitis syndrome; natural desensitization; tryptase.