Iodine is a member of a group of non-metal elements called halogens; other halogens include fluorine, chlorine and bromine. Iodine may also be ingested in foods such as seaweed, seafood and iodised salt. Smaller amounts of iodine are found in vegetables and meat. Iodine is a trace element present throughout the body and is essential for the production of thyroid hormones.
It is not possible to have a true allergy to elemental iodine. Newer iodinated contrast media have improved chemical properties and the incidence of these types of reactions is now much lower. Most of the above reactions to contrast media are not true hypersensitivity reactions immunoglobulin E antibodies are not involved. The reactions are called idiosyncratic, and unlike true hypersensitivity reactions, a previous sensitisation to the agent is not required, nor do these reactions consistently recur in an individual.
Povidone-iodine is a commonly used antibacterial agent that is a compound of iodine and povidone, along with other additives. Povidone is also used in other products such as foods, medicines eg, antihistamines , diuretics, and pain-relievers , hair products, and toothpaste. Allergic contact reactions to povidone-iodine preparations are rare and can be difficult to distinguish from an irritant contact reaction to povidone-iodine. Both reactions can cause redness, induration firmness and multiple small blisters.
Patch testing is often used to help diagnose an allergic contact reaction. However, false positive reactions can occur in this instance due to the irritant properties of povidone-iodine under occlusion. These can help relieve symptoms, such as an itchy rash. Your doctor will also direct you to stay away from foods or other things that do trigger these adverse reactions. Anaphylactic shock is an emergency situation. It may require immediate medical treatment in the form of a shot of epinephrine adrenaline.
Avoiding iodine completely could raise these issues:. Talk to your doctor to determine how you can get enough iodine intake without triggering a reaction. While iodine intolerance and adverse side effects to intravascular contrast dye containing iodine are both uncommon, talk to your doctor about getting tested if you suspect you have a problem with either or suffer from some of the symptoms. Iodine is an important element that your body needs for many of its basic functions.
But how much is too much? Learn how to recognize the signs of…. Shellfish, such as shrimp, clams, scallops, and lobster, are highly nutritious powerhouses. This article reviews different types of shellfish, their…. Food dye allergies are rare, but if you have one, you may be at risk for an anaphylactic reaction. Neti pots have been used for many years as a remedy for allergies and other conditions.
Learn what the benefits are and how to practice nasal…. Researchers say allergic reactions to COVID vaccines are rare, and any such incidents can easily be treated at the vaccination site. Skin testing and radioallergosorbent testing RAST have not been shown to be helpful in the diagnosis.
Small test doses are often not helpful, with reports of severe, life-threatening reactions occurring after small amounts of RCM given, as well as severe reactions with larger doses of RCM occurring after a person tolerates a small dose of IV dye.
An IV-dye allergy can only be diagnosed after symptoms have occurred. Otherwise, it's only possible to determine that a person is at increased risk of a reaction. The treatment of an acute reaction to RCM is similar to that of an adverse reaction from any cause.
Treatment may include injectable epinephrine and antihistamines, as well as the use of intravenous fluids for low blood pressure and shock. It is common in patients with a history of non-severe pseudo-allergic reactions to RCM to be treated with a combination of oral corticosteroids, such as prednisone, and antihistamines, such as diphenhydramine Benadryl before any future contrast administrations.
Patients with a history of severe reactions should avoid radiocontrast media except in specific, severe circumstances under the direction of a healthcare provider. If you're concerned about a potential reaction to RCM, talk to your healthcare provider about the risks and benefits of performing a test with RCM and whether alternatives are available. Your healthcare provider may be able to gain similar information by performing an MRI scan which uses gadolinium-based contrast rather than a CT scan.
In patients with a history of severe reactions, radiocontrast should be completely avoided except in specific extreme circumstances under healthcare provider supervision. These are generally considered safe, but there is a risk of nephrogenic systemic fibrosis, a rare disease that mostly affects the skin, and contrast-induced nephropathy, which causes a loss of kidney function. These complications are most common among people with existing kidney disease.
If you have a history of allergies, you may need to take medication before receiving the contrast dye to prevent having a serious allergic reaction. You may have some sensations, though:. Any history of allergy increases your risk of having a reaction to contrast agents.
However, your healthcare provider may be able to provide medication that you can take before a scan to prevent a reaction. Sign up for our Health Tip of the Day newsletter, and receive daily tips that will help you live your healthiest life.
The use of contrast media. Side effects of radiographic contrast media: pathogenesis, risk factors, and prevention. Biomed Res Int. Clinical pharmacology, uses, and adverse reactions of iodinated contrast agents: a primer for the non-radiologist. Mayo Clin Proc. Shellfish allergy and relation to iodinated contrast media: United Kingdom survey. World J Cardiol. Radiological Society of North America.
Contrast Materials. Updated July, 23, Mount Sinai School of Medicine.
0コメント