Anaphylactic Shock Due to Allergy to Macrogol 4000 Contained in SonoVue&reg

SonoVuer Milan, Italy) is an ultrasound contrast medium which contains polyethylene glycol (PEG) or macrogol, an excipient responsible for severe allergic reactions, especially through the parenteral route, and widely used, especially in the health field. We present an adult patient who experienced an IgE-mediated anaphylactic shock due to macrogol contained in SonoVue®, as demonstrates the skin tests realized. The allergy study has been useful in our case because it has guided us in the preventive measures to advice to the patient, who has to avoid not only SonoVue® but also other products that contain macrogol. We consider this case of interest because it is an allergic adverse reaction to SonoVue® in which its excipient, macrogol, has acted like the allergen responsible. We have to add SonoVue® to the list of the products that contain macrogol in their composition and keep in mind the possible allergenic capacity of this excipient for suspecting its responsibility, especially in those patients with multiple drug allergy and/or reactions to products of different natures like ultrasound gels, topical products (e.g. toothpastes, antiseptics, sunscreens, etc.), plasma expanders and others.