Abstract
A nine-year-old egg allergic child developed anaphylaxis after ingesting
the lysozyme-containing over-the-counter-drug Lysopaine®. He complained
of a sore throat without fever or cough. His mother administered him one
sublingual tablet of the over-the-counter drug Lysopaine®, containing 20
mg lysozyme hydrochloride. A few minutes after intake of the drug, he
developed anaphylaxis and received 300 mg intramuscular epinephrine. HE
was not exposed to other allergens. The responsibility of lysozyme was
confirmed by positive skin prick tests for Lysopaïne® and the presence
of specific IgE against lysozyme. When giving this treatment to her son,
his mother had no idea that it could contain egg protein and she did not
perceive lysozyme as an allergenic protein. However, the box mentioned
the presence of lysozyme and also specified “contains lysozyme
extracted from egg”. Lysozyme, a minor egg allergen, may induce
anaphylaxis in egg-allergic patients. Lysozyme can be found in many
commonly consumed industrial food and drug products and its labelling
may be misleading. Our observation highlights the importance of properly
educating allergic patients to recognize allergens, even minor ones.