Type I hypersensitivity in an asthmatic child allergic to peanuts: was soy lecithin to blame?

Background: Soy lecithin is widely used as an emulsifier, not only in topical skin care products but also in various drugs administered either topically, orally, or intravenously or by inhalation. Patients strongly allergic to soy and/or peanuts can develop an anaphylactic reaction when exposed to soy lecithin.

Method: We report a 3-year-old asthmatic boy, allergic to peanuts, who was treated at the emergency department for an exacerbation of asthma following an upper respiratory tract infection.