What is Iodine Allergy?
It is a common radiology procedure to question patients about iodine allergy, if they require the administration of intravenous contrast material. Intravenous contrast material has iodine which can cross react with substances which have a high content of Iodine such as seafood. The increasing trend of the consumption of iodine rich food such as salt, bread, seafood are the reasons which make the general population suffer from Iodine allergies.
Iodine and Immune reactions: Iodine is a trace element which is broken down in our stomach to its ionized form also termed as iodide. There are various dietary sources which provide our body with this trace element. Fish has a high content of this element as it is believed that all the iodine present in the earth’s soil has been washed in to the oceans. Antigen –antibody reactions are a characteristic response of the immune system in which the B and the T lymphocytes take part. Iodine on the other hand is a very small molecule which is unable to act as an antigen; therefore it functions as a hapten. While functioning as a hapten it can use a carrier molecule to kindle an antibody reaction .Iodine allergy can be characterized by symptoms such as nausea, vomiting, asthmatic attack and skin irritation.
Iodine allergy and Contrast material: Allergies can happen due to contrast material cross reaction, which contains traces of iodine; these are used for intravenous injections in Radiology procedures. The contrast material is composed of benzoic acid derivatives. This can cause idiosyncratic or nonidiosyncratic reactions. The process in which idiosyncratic reactions take place is ambiguous as there are lot of theories to explain it. On the other hand nonidiosyncratic reactions generally contribute to iodine mumps, which is a swelling of salivary glands. In other cases there can be swelling of the lachrymal glans and rashes on the skin. This condition is also termed as Iodism.
Symptoms of Iodine allergy: Iodine allergy is also caused due to seafood and can have immune as well as nonimmune responses .Seafood can cause allergy, can be a source of infection and can have high toxicity levels which makes it one of the common causes of Iodine allergy. Reactions to food intolerance can appear in a couple of hours and in some cases can be fatal. This hypersensitivity is generally contributed to Immunoglobulin E .For instance skin prick tests are done with shrimp extract to ascertain any sensitivity to seafood like shrimps. Iodism can take place in patients who have burn injuries and also in neonates.
It is important to evaluate the risk factors before subjecting any patient with iodine allergy to intravenous material. Although eight five out of every hundred people do not have any contrast reactions. The different types of causes of iodine allergy such as contrast reaction, allergies by seafood and povidine dermatitis have specific immune causes. Presence of a seafood allergy can make a patient more viable (almost three times) to contrast reactions. The exact causes of the Iodine allergy should be ascertained and treated accordingly. What may appear as a mild initial reaction can aggravate in to a life threating condition.