Risk of Povidone-Iodine Gargles or general use: very rare. How to do a Patch Test for Povidone Iodine

 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. 

Patch Test:

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:

  • abdominal pain
  • nausea or vomiting
  • diarrhea
  • confusion
  • altered level of consciousness
  • dizziness
  • lightheadedness
  • hives
  • difficulty breathing
  • heart palpitations
  • rapid pulse
  • low blood pressure

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.


Letter to the Editor 


Free Access

Recurrent anaphylaxis caused by topical povidone‐iodine (Betadine)

First published: 03 June 2013


Citations: 15
Conflict of interest: The authors do not have any conflicts of interest.
Dear Editor,

Povidone‐iodine (Betadine) is a rare cause of IgE‐mediated allergy. We report a case of recurrent anaphylaxis in a 12‐year‐old girl following the use of Betadine swabs.

The patient initially presented at 9 years old with generalized urticaria, facial angiooedema and shortness of breath, following a scratch from a rabbit. She was found to have wheeze and was treated with intramuscular adrenaline. In her history, she had mild coroyzal symptoms after handling the rabbit, and with a positive skin prick test (SPT) to rabbit (7 × 7 mm), she was diagnosed with anaphylaxis to rabbit scratch. The rabbit was removed from the home.

She subsequently had a second episode of anaphylaxis at 12 years of age following a cut to her skin. Suspicion fell on the antiseptic Betadine (povidone‐iodine), which was used to clean the wound and which her mother recalled also using on the first occasion. SPT was positive (9 × 9 mm), and she was diagnosed with recurrent povidone‐iodine anaphylaxis. She was provided with a medic alert bracelet, an adrenaline autoinjector, and was advised where possible to avoid exposure to medicines and other products containing povidone and povidone‐iodine.

Povidone‐iodine is a stable iodophor solution containing a water‐soluble complex of iodine and polyvinylpyrrolidone. Fewer than 10 documented IgE‐mediated allergic reactions have been reported following povidone‐iodine exposure, occurring after topical, vaginal or rectal applications.14 The allergenic determinant in cases of immediate hypersensitivity is thought to be povidone, based on the presence of IgE antibodies to povidone in the serum of allergic patients,1 and the occurrence of anaphylaxis to povidone without iodine,5 including in a child who had previously reacted to Betadine.6

Povidone is a mixture of synthetic polymers,7 which is widely distributed, being used as an additive in food products, a dispersant in hairsprays, a suspending and coating agent in tablets, a film forming compound for eyedrops and a retardant for subcutaneous injections.8 It is present in 20% of tablets on the market in Germany9 in more than 800 pharmaceuticals products in Japan,10 and a brief search of MIMS online database (http://proxy36.use.hcn.com.au/Search/QuickSearch.aspx?ModuleName=Product+Info) identified povidone in 650 Australian products such as tablets, eyedrops, gargles and skin creams. Unfortunately, although it is compulsory to declare povidone when it is an active ingredient, its declaration as an excipient is less straightforward. For instance, the listing of excipients in product information sheets is not required by the Therapeutic Goods Administration for over‐the‐counter and complementary medicines.11 Therefore, if a patient is diagnosed as being allergic to povidone‐iodine, while avoidance should be advocated,710 this may be difficult, and given the risk of accidental exposure to povidone, the supply of an adrenaline autoinjector has been recommended.10

Finally, the long‐standing widely held belief that a patient who has had a reaction to one iodine‐containing compound (e.g. Betadine or seafood) is at greater risk of reacting to another, such as radiocontrast medium, is not supported by evidence and appears to be a myth.12

2002 Mar;28(3):210-4.

 doi: 10.1046/j.1524-4725.2002.01161.x.

Dilute povidone-iodine solutions inhibit human skin fibroblast growth



Background: Povidone-iodine solutions are widely used and highly effective antiseptics. Although commonly used at full strength, this concentration appears to be toxic to the cells involved in wound healing. Few systematic studies of povidone-iodine toxicity have been reported. The effects of various dilutions of 10% povidone-iodine solution on the growth of human diploid fibroblasts were assessed using in vitro cell culture.

Objective: The purpose of this study was to systematically evaluate the toxicity of povidone-iodine on living cells using an in vitro model.

Methods: Adult skin fibroblasts and fetal lung fibroblasts were subcultivated at various seeding densities of 3000-10,000 cells/cm2 and grown in polystyrene tissue culture flasks under an atmosphere containing 5% O2, 5% CO2, and 90% N2. Cells were grown in a medium containing various concentrations of povidone-iodine (1%, 0.1%, 0.025%, 0.01%, and 0%). Cell attachment was reduced by 0.1% and 1% povidone-iodine in our initial studies; subsequent experiments were performed by changing the medium to contain the povidone-iodine 24 hours after seeding. Growth curves were performed by counting triplicate cultures every 48 hours for 250-300 hours.

Results: Fibroblast growth was progressively retarded at 0.01% and 0.025%, and totally inhibited by 0.1% and 1% povidone-iodine solutions. Partial recovery of cell growth after limited exposure of cultures to dilute solutions of povidone-iodine was noted.

Conclusion: This study shows that even dilute solutions of povidone-iodine are toxic to human fibroblasts. The results indicate that caution should be used when povidone-iodine is placed on an open wound, and that prolonged contact with viable uncontaminated tissue should be avoided.

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