Iodine is an essential mineral found in many foods, such as seafood. The thyroid gland uses iodine to make thyroid hormones, which help control growth, repair damaged cells, and support a healthy metabolism Iodine is not considered an allergen (ie, triggers an allergic response) since it occurs naturally in the body. However, some medications, solutions, or concentrations that contain iodine may cause an allergic reaction. These reactions may be caused by the iodine (ie, a true iodine allergy) or by other substances that have been mixed with iodine.
Before use iodine excessively (ie, for frequent wound scrubs or gargles to prevent COVID-19), consider a patch test to be sure you are not allergic.
If they think you’re allergic to the povidone in povidone-iodine solution, ask your MD to do this test. Some may be able to do this at home, but be sure to monitor the person having the test to be sure they do not have a rare severe reaction.
1. Apply a small amount of povidone-iodine to a patch or bandaid’s central part and then placed on your skin.
2. Check each day to see if you had a reaction.
Gargling diluted povidone-iodine to prevent a cold, flu, or COVID-19 appears to be safe in adults. Povidone iodine has been used for years in kids for wound cleaning. There have been no publications of gargling povidone-iodine in kids to prevent . I have personally used it on myself and children to prevent viral infections. The goal is to prevent aspiration which has never happened. This is the only risk I could find for adults or kids (aside from allergy/anaphylaxis as noted above and in below reference [in child with multiple exposures to povidone iodine after an initial allergy: thus do not use povidone iodine if your child is allergic).
There is 1 published case of a 16yo girl who was intubated, about to have surgery when 10% Povidone iodine contaminated breathing tube and caused an aspiration. pneumonia. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3198188/
Aspiration of Povidone Iodine can damage lung tissue so avoid for now all aspiration or nebulization. https://www.researchgate.net/publication/51703528_Lung_injury_induced_by_the_pulmonary_instillation_of_povidone-iodine_in_rats
More information below:
Exposure to mixtures that also contain iodine can cause some of the following reactions:
- itchy rash that comes on slowly (contact dermatitis)
- hives (urticaria)
- anaphylaxis, which is a sudden allergic reaction that can cause hives, swelling of your tongue and throat, and shortness of breath
Anaphylactic shock is the most severe form of anaphylaxis and is life-threatening. It requires emergency medical attention.
Symptoms of anaphylaxis include:
Certain solutions and foods that contain iodine can be the cause of an adverse reaction:
- Povidone-iodine (Betadine) is a solution commonly used as a skin disinfectant in medical settings. It may cause a rash in sensitive people.
- Iodinated contrast dye can also cause an allergic reaction. This dye is an X-ray radiocontrast agent used for intravascular injections (injections into blood vessels). Contrast dyes containing iodine have been responsible for severe reactions (including deaths) in a very limited number of people. Those who have an allergy or other adverse effect to iodinated radiocontrast dye may be given systemic glucocorticosteroid before receiving iodinated contrast. Or use of iodinated contrast may be avoided altogether.
- Foods that contain iodine, such as fish and dairy, can also cause an allergic reaction.
- Amiodarone (Cordarone, Pacerone) is a medication that’s used to manage atrial fibrillation and other heart rhythm diseases in those with cardiac conditions. Currently, experts know of only one case of suspected cross-reactivity in a person who received amiodarone and iodine-containing contrast. Doctors should use caution when prescribing amiodarone for people who have problems with iodine-containing contrast. However, the risk of a true allergic reaction is very low.