Allergie aux médicaments et aliments iodés : la séquence allergénique n’est pas l’iode

Clinical and forensic aspects of potassium iodide: Suddenly in high demand across Europe due to fears of radiation poisoning from a nuclear attack in Ukraine

Potassium iodide has demonstrated several therapeutic applications over time, being the choice for shielding the thyroid during radiation emergencies involving radioiodine release. Amidst the ongoing military conflict between Ukraine and Russia and the growing concern regarding the potential deployment of nuclear weapons, there has been a surge in the demand for potassium iodide across Europe. This work aimed to comprehensively review the current knowledge regarding the pharmacology, physiology, adverse effects, the protective role in reducing the risk of thyroid cancer and recommendations for potassium iodide use during radiation emergencies. Evidence on adverse effects is scarce, as potassium iodide is generally well-tolerated. Guidelines for thyroid blocking with potassium iodide during radiation emergencies suggest that, among populations vulnerable to radioiodine exposure, the benefits of potassium iodide outweigh the risks of adverse effects. Controversial topics surrounding the utilization of potassium iodide in radiation emergencies include the prophylaxis in iodine-deficient regions and following the detonation of dirty bombs, whether granule formulations versus tablets should be used and mental health concerns. Although the rise in demand seems to be a justified security measure, it is essential to recognize that potassium iodide protects the thyroid from radioiodine and does not impact the body's absorption of other radioactive materials or defend against external radiation exposure.

The Use of Iodophor-Impregnated Drapes in Patients With Iodine-Related Allergies: A Case Series and Review of the Literature

Background

The use of iodophor-impregnated adhesive drapes have become almost universally incorporated into standard practice of arthroplasty draping technique. Iodine-related allergies in patients planned for joint replacement present a challenge in terms of the best course of action to minimize complications and optimize outcomes.

Methods

This is a retrospective case series of patients that received an iodophor-impregnated drape as part of draping for a total hip or knee arthroplasty at a single orthopaedic-specific hospital with documented iodine-related allergies. From 2015 to 2023, 9816 total hip arthroplasty and total knee arthroplasty cases were reviewed, and 135 were documented to have an iodine-related allergy for a prevalence of 1.38%. Intraoperative and postoperative records were reviewed to screen for an allergic reaction or wound healing issues that may have been related to an adverse reaction to the use of the iodophor-impregnated drape.

Results

Of the 135 patients, 43 had iodine listed as an allergy, 85 had shellfish, 20 had iodinated contrast media, and 3 had povidone iodine. Sixteen patients had a cluster of iodine-related allergies. There were no intraoperative reports of an allergic reaction to this drape. There were four superficial wound problems, none of which were documented to relate to an allergic dermatitis reaction, and none required further surgery.

Conclusions

Patients reporting iodine-related allergies were present in 1.38% of patients undergoing hip or knee arthroplasty in our series. We encountered no allergic reactions or adverse outcomes that could be attributed to the use of iodiphor impregnated drapes in these patients.

Contrast-Induced Neurotoxicity: An Inside Look at a Rare Presentation

Imaging modalities frequently utilize iodinated-based contrast agents (IBCAs) to assist professionals in deficit identification and improve clinical outcomes for patients. However, they are not without risk. In patients with post-radiological neurological deficits, contrast-induced neurotoxicity (CIN) should be among the top differentials. In this case report, we present the case of a 61-year-old female who experienced classical signs and symptoms of neurotoxicity after a cerebral angiogram. The patient's clinical detriments stemming from iodinated contrast resolved after a multi-day treatment of high-dose steroid use.

Akute Schwellung im Halsbereich nach iodhaltigem Kontrastmittel – der oft unerkannte Iodmumps anhand von drei Fallbeispielen

Es werden drei Patientinnen vorgestellt, die zur Abklärung einer akuten Halsschwellung nach einer Untersuchung mit iodierten Kontrastmitteln zugewiesen wurden. Bei allen drei war ein akutes Angioödem vermutet worden, das allerdings nicht ausreichend auf Antihistaminika und Kortikosteroide ansprach. Es wurde schließlich ein sog. „Iodmumps“ oder Iod-assoziierte Sialoadenopathie diagnostiziert. Sonografisch und histologisch finden sich lediglich ein Ödem der Speicheldrüsen, hingegen keine Hinweise für eine ausgeprägte entzündliche Reaktion. Diese Komplikation ist nicht so selten und wird von Iod selbst ausgelöst, wie mit einer Provokation mit Iod-Kaliumiodid (Lugolʼscher Lösung) nachgewiesen werden konnte. Die pathophysiologisch ungeklärte Iod-assoziierte Sialoadenopathie wird somit als idiosynkratische Reaktion klassifiziert.

Successful prolonged cardiopulmonary resuscitation after intraoperative cardiac arrest due to povidone-iodine allergy: A case report

BACKGROUND

Iodophor (povidone-iodine) is widely used clinically because of its broad-spectrum antibacterial effects. Although extremely rare, it may cause anaphylactic shock, which itself carries the life-threatening risk of cardiac arrest.

CASE SUMMARY

We present a case in which a patient with postoperative infection went into anaphylactic shock and cardiac arrest caused by povidone-iodine during secondary surgery. The patient was successfully resuscitated by 2 h of cardiopulmonary resuscitation.

CONCLUSION

This is the first known case of cardiac arrest caused by povidone-iodine allergy.

Shelling the myth: allergies to Iodine containing substances and risk of reaction to Iodinated contrast media

PURPOSE

In excess of 100 million procedures using iodinated radio-contrast media are conducted each year. There is a common misunderstanding regarding the links between allergy to iodinated substances and the risk of allergic reaction to intravenous iodinated contrast agents. These perceived risks are managed via administration of corticosteroids or avoidance of iodinated contrast altogether.

METHODS

An extensive review of published literature on scientific databases and international guidelines was conducted in order to inform the research question. A questionnaire was formulated and distributed to hospital doctors in four tertiary centres. Within this questionnaire, hospital doctors were presented with six different scenarios of bona fide allergy to iodinated substances (e.g. shellfish) and asked to select the treatment response option which they deemed to be the most suitable from a choice of three (standard contrast scan/delay scan with pre-medication/change to non-contrast scan).

RESULTS

Eighty-seven questionnaire responses were received. Contrast (standard protocol) was the most appropriate regimen in the setting of all the listed allergies. This was identified correctly by 76%, 69%, 44%, 32%, 18% and 14% for kiwi, fish, poly-food, shellfish, betadine and tincture of iodine allergies, respectively.

CONCLUSIONS

There is a lack of understanding amongst local junior medical staff regarding administration of iodinated contrast media to patients with a history of allergy to iodinated substances. These misconceptions may potentiate the unnecessary usage of pre-medication and ordering of non-contrast scans in the setting of a gold-standard enhanced scan. Findings from this study suggest that there is a need for future education efforts targeted during the basic specialty training stage.

Fidelity of Electronic Documentation for Reactions Prompting Premedication to Iodinated Contrast Media

PURPOSE

The aims of this study were to assess the fidelity of electronic health record documentation prompting premedication to iodinated contrast media and to determine the appropriateness of administered premedication on the basis of that documentation.

METHODS

In this retrospective quality assurance cohort study, medication adverse events recorded in electronic health records between January 1, 2018, and August 31, 2019, to "iodine," "iodine-containing products," and "iodinated contrast media" were identified (N = 4,309); entries missing documentation (n = 1,651) and breakthrough reactions (n = 22) were excluded. Reaction description, severity, and free-text comments were used to categorize each entry as concordant (documentation matches recorded severity per the ACR Manual on Contrast Media version 10.3), discordant (description-severity mismatch, agent unrelated to iodinated contrast media, not a hypersensitivity reaction), or unclear. A subset of patients undergoing premedication was identified, and premedication was categorized as appropriate, inappropriate, or unsure on the basis of the index reaction using the aforementioned framework. Descriptive statistics were calculated.

RESULTS

There were 2,636 adverse event entries in 2,441 patients: 59.9% (1,578 of 2,636) were classified as concordant, 30.2% (797 of 2,636) as discordant (n = 377 not a hypersensitivity reaction, n = 317 description-severity mismatch, and n = 103 unrelated agent), and 9.9% (n = 261) as unclear documentation. For the premedicated subset, concordance classification was feasible for 202 unique patients premedicated 335 times. Premedication was appropriate in 72% (240 of 335) and inappropriate in 22% (73 of 335); 17% of premedication events (56 of 335) were inappropriately administered for a prior physiologic reaction.

CONCLUSIONS

Premedication prompts in the electronic health record are often erroneous because of inaccurate coding, incomplete data, and reaction misclassification. These errors result in inappropriate premedication for a substantial minority of patients.

[Update on perioperative hypersensitivity reactions: joint document from the Brazilian Society of Anesthesiology (SBA) and Brazilian Association of Allergy and Immunology (ASBAI) - Part II: etiology and diagnosis]

This second joint document, written by experts from the Brazilian Association of Allergy and Immunology (ASBAI) and Brazilian Society of Anesthesiology (SBA) concerned with perioperative anaphylaxis, aims to review the pathophysiological reaction mechanisms, triggering agents (in adults and children), and the approach for diagnosis during and after an episode of anaphylaxis. As anaphylaxis assessment is extensive, the identification of medications, antiseptics and other substances used at each setting, the comprehensive data documentation, and the use of standardized nomenclature are key points for obtaining more consistent epidemiological information on perioperative anaphylaxis.

Update on perioperative hypersensitivity reactions: joint document from the Brazilian Society of Anesthesiology (SBA) and Brazilian Association of Allergy and Immunology (ASBAI) - Part II: etiology and diagnosis

This second joint document, written by experts from the Brazilian Association of Allergy and Immunology (ASBAI) and Brazilian Society of Anesthesiology (SBA) concerned with perioperative anaphylaxis, aims to review the pathophysiological reaction mechanisms, triggering agents (in adults and children), and the approach for diagnosis during and after an episode of anaphylaxis. As anaphylaxis assessment is extensive, the identification of medications, antiseptics and other substances used at each setting, the comprehensive data documentation, and the use of standardized nomenclature are key points for obtaining more consistent epidemiological information on perioperative anaphylaxis.

Skin Preparation Techniques for Orthopedic Foot and Ankle Surgery: A Current Concepts Review

Surgical site infection (SSI) following orthopedic foot and ankle surgery is associated with morbidity, mortality, and cost to the healthcare system. The local anatomy and physiology predispose patients undergoing procedures to elevated risk. In particular, sterilizing of the webspaces, nailfolds, and subungual areas presents challenges, and the preferred skin antisepsis technique for foot and ankle procedures has not yet been defined. Skin antiseptic solutions (SASs) consist of 3 main categories: alcohol, chlorhexidine, and iodine-based solutions. This review of the literature supports a combined chlorhexidine and alcohol preparation technique; however, there are a number of studies that suggest otherwise. In addition, there is variable evidence for the use of alternatives to the standard soft sponge application technique, including immersion, bristled brush, and cotton gauze application. These alternatives may have a particular advantage in the forefoot. Most studies to date use growth from skin swab cultures after skin preparation as the primary outcome. Higher-level studies with large subject populations and more meaningful clinical outcomes will be required to solidify guidelines for preoperative skin antisepsis prior to foot and ankle procedures.Level of Evidence: Level V, expert opinion.

[Recurrence of drug eruption after renewed injection of iodinated contrast medium in patients with known allergic contraindications]

BACKGROUND

Iodinated contrast media (ICM) are used extensively by both radiologists and cardiologists. Injection of such products can induce immediate hypersensitivity reactions, some of which are IgE-mediated, and delayed hypersensitivity reaction with all types of drug eruptions being reported. Allergy tests, whether patch-tests or intradermal tests, are useful to confirm whether patients are allergic. At the end of these tests, depending on the reaction (chronology and clinical symptoms) and the results of the skin tests, patients are given an allergy card as well as a detailed certificate indicating the various ICM contraindicated and those allowed.

OBSERVATIONS

We report herein three cases of patients experiencing a confirmed allergic eruption after injection of ICM, and whose recommendations and contraindication were not taken into consideration, leading to recurrence of eruption after renewed ICM injection.

DISCUSSION

The three cases we report herein underscore the lack of knowledge concerning eruptions induced by ICM, particularly among radiologists. Better dissemination of information about the existence of such reactions appears necessary amongst the medical professionals concerned.