Contrast media and cutaneous reactions. Part 2: Delayed hypersensitivity reactions to iodinated contrast media

Very rare adverse reactions to intravascular contrast media: From Kounis to sweet syndrome

Intravascular administration of contrast media may inadvertently result in adverse drug reactions (ADR) including selected hypersensitivity reactions. This review highlights some very rare ADR, aiming to alert imaging physicians to these conditions and to prompt adequate management. This is particularly relevant for Kounis syndrome, an immediate hypersensitivity reaction involving the coronary arteries. The acute management of Kounis syndrome can be challenging, as it requires continued contrast media administration, while balancing the simultaneous coronary reperfusion that requires vasodilatation with anti-allergic treatment that may involve vasoconstrictor agents. For other adverse reactions, referral to a drug allergy specialist is highly recommended to assess causality and identify safe alternatives. CLINICAL RELEVANCE STATEMENT: Cardiologists and radiologists must recognize the key symptoms of these very rare adverse reactions to contrast media to promptly initiate the appropriate therapy and refer patients for allergological evaluation, ideally within 1-6 months after the reaction.

Acute generalized exanthematous pustulosis induced by iodinated contrast media: a case report

Acute generalized exanthematous pustulosis (AGEP) is a rare pustular eruption commonly triggered by drugs. It's characterized by acute onset of pustules on erythematous-edematous skin and often presents with fever. This report describes AGEP following exposure to iodinated contrast media (ICM), specifically iobitridol, in a 68-year-old male with multiple comorbidities. The patient developed characteristic erythematous patches with pustules on the body after initial CT imaging with ICM for a prostate abscess. Histological findings and recurrence following re-exposure confirmed AGEP, which was attributed to ICM. This case emphasizes the need for awareness of ICM as a potential trigger for AGEP. Management included topical steroids and antihistamines, resulting in a rapid recovery.

Management and Prevention of Hypersensitivity Reactions to Radiocontrast Media: A Consensus Statement from the American College of Radiology and the American Academy of Allergy, Asthma & Immunology

Intravenous iodinated contrast media (ICM) is widely used in the United States, and it is imperative to provide guidance on the management of adverse reactions to ICM as well as the preparation, planning, and potential premedication for patients with previous reactions. Currently there is a discordance between the American College of Radiology Contrast Manual, which recommends premedication to prevent repeat hypersensitivity reactions to ICM, and the Anaphylaxis 2020 Practice Parameters Update, which recommends against routine administration of glucocorticoids and/or antihistamines to prevent anaphylaxis with prior ICM hypersensitivity reactions. A task force of experts from radiology who are also members of the American College of Radiology Committee on Drugs and Contrast Media and expert allergists/immunologists including members of the Adverse Reactions to Drugs, Biologics and Latex Committee of American Academy of Allergy, Asthma & Immunology evaluated the scientific evidence to develop consensus recommendations that are endorsed by both organizations. The task force took into account the strength of evidence and balanced the potential risks of recurrent reactions with those of premedication and product avoidance when making these recommendations to improve and standardize the care of patients who experience or have a history of reaction to ICM. © Radiological Society of North America and American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc on behalf of American Academy of Allergy, Asthma & Immunology and by Radiological Society of North America. All rights are reserved, including those for text and data mining, AI training, and similar technologies. This paper was jointly developed by The Journal of Allergy and Clinical Immunology: In Practice, Radiology and jointly published by Elsevier Inc and Radiological Society of North America. The articles are identical except for minor stylistic and spelling differences in keeping with each journal's style. Either citation can be used when citing this article. Keywords: Contrast allergy, Contrast hypersensitivity, Iodinated contrast allergy, Iodinated contrast hypersensitivity, Anaphylaxis, Contrast skin testing, Contrast switching, Contrast reaction, Delayed contrast reaction, Immediate contrast reaction.

Management and Prevention of Hypersensitivity Reactions to Radiocontrast Media: A Consensus Statement From the American College of Radiology and the AAAAI

Intravenous iodinated contrast media (ICM) is widely used in the United States, and it is imperative to provide guidance on the management of adverse reactions to ICM as well as the preparation, planning, and potential premedication for patients with previous reactions. Currently there is a discordance between the American College of Radiology Contrast Manual, which recommends premedication to prevent repeat hypersensitivity reactions to ICM, and the Anaphylaxis 2020 Practice Parameters Update, which recommends against routine administration of glucocorticoids and/or antihistamines to prevent anaphylaxis with prior ICM hypersensitivity reactions. A task force of experts from radiology who are also members of the American College of Radiology Committee on Drugs and Contrast Media and expert allergists/immunologists including members of the Adverse Reactions to Drugs, Biologics and Latex Committee of American Academy of Allergy, Asthma & Immunology evaluated the scientific evidence to develop consensus recommendations that are endorsed by both organizations. The task force took into account the strength of evidence and balanced the potential risks of recurrent reactions with those of premedication and product avoidance when making these recommendations to improve and standardize the care of patients who experience or have a history of reaction to ICM.

Diagnosing and Managing Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis in Adults: Review of Evidence 2017-2023

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening reactions associated with long-term disabling sequelae. In the acute phase, the best supportive care in expert centers is the cornerstone of treatment. The follow-up is prolonged and multidisciplinary, according to the patient's needs. In this paper, we review the evidence from 2017 to 2023 for the diagnosis and management of SJS/TEN in adults. On the basis of this review and our own experience, we present recommendations for the diagnosis of SJS/TEN in adults, management in the acute phase (best supportive care; prevention of infections; skin, ocular, and other mucosa management; intensive care measures; and etiological treatment), and follow-up. The most frequent sequelae are cutaneous, ocular, and psychological. High-quality studies assessing the efficacy of immunomodulating agents (eg, cyclosporine, corticosteroids, intravenous Igs, and anti-TNF agents) in accelerating healing and reducing mortality are still lacking. In addition, we propose avenues for future studies.

Rare delayed hypersensitivity reactions to contrast media: Severe cutaneous adverse reactions

The risk of developing a severe delayed cutaneous reaction (SCAR) is very low following iodine-based contrast medium (ICM) administration and extremely low following gadolinium-based contrast agent (GBCA) administration. However, SCAR can be very severe and potentially life-threatening. It is crucial for the imaging physician to recognize danger signals: bullous skin eruption, skin erosion and detachment, mucosal involvement, systemic symptoms, and laboratory abnormalities. Patients suspected of having a SCAR should be urgently referred to a drug allergy specialist or dermatologist. To prevent recurrence, consider exploring alternative imaging modalities and avoid administering the same type of contrast medium involved: if the culprit is a ICM, avoid all ICM and if the culprit is a GBCA, avoid all GBCA. In an allergy centre with experience in SCAR evaluation a careful allergologic analysis may be performed safely several months after the patient has recovered from SCAR. However, allergologic analysis is challenging due to the lack of reliable in vitro diagnostic tests and the risks of in vivo diagnostic tests, particularly drug provocation tests.

Bullous drug eruption

Reactions to intravenous contrast media can be immediate or delayed, with delayed hypersensitivity reactions occurring 1 h to 7 days after administration. Severe reactions such as generalized bullous fixed drug eruption are rare. Skin tests, including patch and intradermal tests, are used to identify culprit agents. There are only a few reports about this issue. Thus, our case will help to raise awareness about this cutaneous drug reaction due to radiocontrast.

Two Rare Cases of Feline Toxic Epidermal Necrolysis: A Novel Therapeutic Approach With Medical-Grade Honey

Toxic epidermal necrolysis (TEN) is an acute and life-threatening dermatological condition that is drug-induced and characterized by extensive epidermal detachment. These lesions should be protected from infection using a product that has a low risk of reactivity. Medical-grade honey (MGH) exerts antimicrobial and wound-healing effects while posing a low risk of exacerbating TEN. In this case report, we are the first to describe the use of MGH for wound management in two feline TEN patients. Case 1 involved a 1-year-old female British shorthair cat, while Case 2 featured a 1-year-old female mixed-breed cat. Both patients presented to the hospital with various symptoms, including fever, tongue lesions, and lesions in the abdominal area following ovariohysterectomy surgery. TEN was confirmed via histopathological examination. The suspected cause of TEN in both cases was the iodine present in the surgical scrub. Tongue lesions were addressed with a liquid diet, and all xenobiotics were immediately withdrawn as a precaution. MGH products supplemented with vitamins were applied to the abdominal wounds following a wound lavage with Ringer's lactate. Daily dressing changes were performed without discomfort, pain, or any adverse reactions. In both cases, debridement became evident after just 1 day, and the patients fully recovered after 12 days of MGH therapy. This case report demonstrates for the first time the successful use of supplemented MGH for wound management in veterinary patients with TEN. The patients did not have any adverse reactions to the treatment, while MGH dressings provided antimicrobial protection and wound-healing effects. Furthermore, these cases highlight the importance of rapid diagnosis and immediate drug withdrawal to increase the survival rate. Overall, supplemented MGH is a safe and effective method to treat TEN-related lesions in feline patients.

Adverse reactions to radiological contrast media: Prevention and treatment

Radiological contrast media, both iodinated and gadolinium-based, can lead to adverse reactions. Type A reactions are related to the pharmacological characteristics of the contrast, including side, secondary and toxic effects. Post-contrast acute kidney injury is the most frequent adverse reaction to iodinated contrast media. Less frequently, thyroid, neurological, cardiovascular, haematological, and salivary gland effects are also detected. With gadolinium-based contrast agents, nausea is the most frequent reaction, but there is also a risk of producing nephrogenic systemic fibrosis and cerebral deposits of uncertain significance. The most effective way of avoiding type A reactions is to decrease the dose and frequency of contrast media administration, especially in patients with pre-existing renal insufficiency. To prevent post-contrast acute kidney injury, adequate hydration of the patient should be maintained orally or intravenously, avoiding prolonged periods of liquid fasting. On the other hand, hypersensitivity reactions are dose-independent and clinically can range from mild cutaneous reactions to anaphylaxis. This article proposes an algorithm that differentiates between nonspecific reactions and true hypersensitivity reactions, as well as levels of severity. It also provides a treatment scheme for immediate reactions adjusted to the severity level, with a focus on the management of anaphylaxis and an early intramuscular administration of adrenaline. Finally, it sets out recommendations for the management of patients with previous hypersensitivity reactions who require elective or urgent contrast administration, favouring the use of alternative contrast media with confirmed tolerance instead of the indiscriminate use of premedication.

Safety of non-ionic contrast media in CT examinations for out-patients: retrospective multicenter analysis of 473,482 patients

OBJECTIVES

This study aimed to explore the incidence of and potential risk factors for adverse drug reactions (ADRs) after non-ionic iodinated contrast media (NICM) administration for CT exams in out-patient settings in China.

MATERIALS AND METHODS

A total of 473,482 out-patients who underwent intravenous NICM between January 1st, 2017, and Dec 31st, 2021, were retrospectively enrolled from three institutions. The occurrence of ADRs and clinical information were recorded. Chi-square test, Poisson regression, and logistic regression analyses were used to evaluate potential ADR risk factors and correlation with demographics, season, and NICM type.

RESULTS

Among the 473,482 patients (mean age 55.22 ± 14.85; 253,499 male) who received intravenous NICM, the overall ADR incidence was 0.110% (522 of 473,482), with 0.099% acute-related drug reactions (469 of 473,482) and 0.0004% serious ADRs (two of 473,482). Iopromide was associated with a higher risk of acute ADRs. Late ADRs were more frequently observed with iodixanol 320. Multi-level logistic regression of patients with acute ADRs and a control group (matched 1:1 for age, gender, NICM, prescriber department, and institution) showed that summer (adjusted OR = 1.579; p = 0.035) and autumn (adjusted OR = 1.925; p < 0.001) were risk factors of acute ADRs. However, underlying disease and scanned body area were not related to a higher ADR incidence.

CONCLUSION

The use of NICM for out-patients is in general safe with a low ADR incidence. The type of contrast medium (iopromide) and the seasons (summer and autumn) were associated with a higher risk of acute ADRs. Late ADRs were more often observed with iodixanol.

CLINICAL RELEVANCE STATEMENT

In comparison to in-patients, out-patients may be exposed to higher risk due to a lack of extensive risk screening, less nursing care, and higher throughput pressure. Safety data about NICM from a large population may complement guidelines and avoid ambiguity.

KEY POINTS

• The incidence and risk factors for adverse events after using non-ionic iodinated contrast media are complex in out-patients. • Non-ionic iodinated contrast media are safe for out-patients and the overall incidence of adverse drug reactions was 0.110%. • There is a higher risk of acute adverse drug reactions in summer and autumn.

Drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms. Part I. Epidemiology, pathogenesis, clinicopathological features, and prognosis

Drug-induced hypersensitivity syndrome (DiHS), also known as drug reaction with eosinophilia and systemic symptoms (DRESS), is a severe cutaneous adverse reaction (SCAR) characterized by an exanthem, fever, and hematologic and visceral organ involvement. Anticonvulsants, antibiotics, and allopurinol are the most common triggers. The pathogenesis involves a complex interplay between drugs, viruses, and the immune system primarily mediated by T-cells. DiHS/DRESS typically presents with a morbilliform eruption 2-6 weeks after drug exposure, and is associated with significant morbidity, mortality, and risk of relapse. Long-term sequelae primarily relate to organ dysfunction and autoimmune diseases. Part I of this continuing medical education activity on DiHS/DRESS provides an update on epidemiology, novel insights into pathogenesis, and a description of clinicopathological features and prognosis.

Toxic Epidermal Necrolysis Secondary to Iodine Versus Methimazole in a Pediatric Patient With Complex Autoimmune Disease

We report a case of a 17-year-old girl who developed toxic epidermal necrolysis (TEN) secondary to preoperative iodine administration before thyroidectomy for Graves' disease. Past medical history was significant for COVID-19 and multisystem inflammatory syndrome in Children (MISC-C), with subsequent diagnoses of type 1 diabetes mellitus (T1DM), Addison disease, and Graves' disease. Her Graves disease was initially managed with methimazole. While there are reported cases of Stevens-Johnson syndrome (SJS) and TEN due to methimazole, the patient had discontinued methimazole over one month prior. Therefore, she likely represents the first case of TEN reported secondary to potassium iodide solution in a pediatric patient. Given the rarity of TEN in pediatric patients, our case highlights the challenges in managing complex autoimmune conditions and underscores the importance of careful medication choices in such cases.

Detection of iodixanol-induced allergic reaction signals in Chinese inpatients: a multi-center retrospective database study using prescription sequence symmetry analysis

Objective

This study aimed to explore the signal detection method for allergic reactions induced by inpatient iodixanol injection.

Methods

A database of 3,719,217 hospitalized patients from 20 large Chinese general hospitals was processed and analyzed using the prescription sequence symmetry analysis (PSSA) method.

Results

126,680 inpatients who used iodixanol and were concurrently treated with anti-allergic drugs were analyzed. In the medical records of these patients, only 32 had documented iodixanol allergies. Statistical analysis identified 22 drugs in 4 categories-calcium preparations, adrenergic/dopaminergic agents, glucocorticoids, and antihistamines-as marker drugs. With time intervals of 3, 7, and 28 days, the adjusted sequence ratios (aSRs) for all anti-allergics and the 4 categories were greater than 1. The 7-day aSRs were 2.12 (95% CI: 2.08-2.15), 1.70 (95% CI: 1.68-1.73), 3.85 (95% confidence interval [CI]: 3.75-2.30), 2.30 (95% CI: 2.26-2.35), and 1.95 (95% CI: 1.89-2.02), respectively. The proportions of adverse drug events indicated by each signal were as follows: all anti-allergics (2.92%-3%), calcium gluconate (0.19%-0.52%), adrenergic/dopaminergic agents (2.20%-3.37%), glucocorticoids (3.13%-3.76%), and antihistamines (1.05%-1.32%).

Conclusion

This first multi-center Chinese inpatient database study detected iodixanol-induced allergy signals, revealing that reactions may be much higher than those in collected spontaneous reports. Iodixanol risk exposure was closer to actual pharmaceutical care findings. PSSA application with ≤7-day intervals appears better suited for monitoring late allergic reaction signals with these drugs.

Delayed hypersensitivity reactions to iodinated contrast media: A diagnostic approach by skin tests

BACKGROUND

Adverse drug reactions to iodinated contrast media (ICM) have risen due to their increasing use in x-ray-based imaging modalities. Delayed hypersensitivity reactions are mainly caused by nonionic monomeric compounds and represent an issue impacting the diagnostic-therapeutic pathways of cancer, cardiology and surgery patients.

OBJECTIVES

To prospectively evaluate the usefulness of skin tests in delayed hypersensitivity reactions to ICM and to evaluate the tolerability of iobitridol, a monomeric nonionic low osmolality compound, as a possible safe alternative.

METHODS

Patients with delayed hypersensitivity reactions to ICM referred to us from 2020 to 2022 were prospectively enrolled in the study. All patients underwent patch test and, if negative, intradermal test with the culprit ICM and iobitridol as alternative.

RESULTS

A total of 37 patients (females 24, 64.9%) were enrolled in the study. Iodixanol and iomeprol were the most frequently involved ICM (48.5% and 35.2%, respectively); 62.2% of patients presented maculopapular eruption, while 37.8% reported delayed urticaria-like rash. Skin tests resulted positive to the culprit ICM in 19 patients (51.4%), 16 to patch test and 3 to intradermal test. Skin tests with iobitridol, tested as alternative, resulted positive in 3/19 patients (15.8%). All 16 patients with negative results to iobitridol were administered this ICM and tolerated it.

CONCLUSIONS

In at least half of patients, delayed-type hypersensitivity was demonstrated by skin tests, particularly by patch test. This diagnostic approach resulted simple, cost-effective and safe, not only to confirm the culprit ICM but also to identify iobitridol as feasible alternative.

[Drug allergy: Fundamental aspects in diagnosis and treatment.]

BACKGROUND

Any substance used as a treatment for any disease can produce harmful or unpleasant events called adverse drug reactions (ADRs). They are due to inherent biological effects of the drug and are caused by immunological and non-immunological mechanisms.

OBJECTIVES

To describe the immunological mechanisms of hypersensitivity reactions (HSR) to drugs, their epidemiology, risk factors, classification, clinical manifestations, diagnosis, treatment, and prognosis.

METHODS

A review of the most current literature in English and Spanish was carried out, in the main databases, related to the HSR of various drug groups.

RESULTS

This study describes the terms used to define ADRs and HSRs, their classification and clinical manifestations, current diagnostic tools, treatment algorithms and prognosis of the most frequently used medications and with the highest prevalence of reported adverse events.

CONCLUSION

ADRs are a challenging entity, with a complex pathophysiology that has not been fully understood. Its approach requires a careful consideration since not all drugs have validated tests for their diagnosis nor a specific treatment. When indicating the use of any drug, the severity of the disease, the availability of other treatments and the potential risks of developing future adverse events should always be taken into consideration.

DRESS syndrome due to iodinated contrast media. A case report

BACKGROUND

The most frequent non-immediate reactions described with iodinated contrast media (ICM) are mild to moderate, however, some cases of patients with severe non-immediate reactions, such as drug eruption with eosinophilia and systemic symptoms (DRESS) have been described.

CASE PRESENTATION

An 84-year-old patient developed DRESS syndrome after administration of ICM ioversol. The patient fullfilled the RegiSCAR diagnostic criteria for DRESS (definite score = 6). He underwent intradermal skin testing (IDT) with the widest panel of ICM available at our center. IDT was positive with ioversol and iomeprol. A punch biopsy was performed on the positive IDT with the culprit drug (ioversol) and histopathology was compatible with a T-cell mediated mechanism.

CONCLUSION

In this case, the IDT-positive biopsy was consistent with DRESS syndrome caused by T-lymphocyte activation, supporting the clinical diagnosis.

Uses of a dedicated 3D reconstruction software with augmented and mixed reality in planning and performing advanced liver surgery and living donor liver transplantation (with videos)

The development of digital intelligent diagnostic and treatment technology has opened countless new opportunities for liver surgery from the era of digital anatomy to a new era of digital diagnostics, virtual surgery simulation and using the created scenarios in real-time surgery using mixed reality. In this article, we described our experience on developing a dedicated 3 dimensional visualization and reconstruction software for surgeons to be used in advanced liver surgery and living donor liver transplantation. Furthermore, we shared the recent developments in the field by explaining the outreach of the software from virtual reality to augmented reality and mixed reality.

Iodinated contrast-induced Stevens-Johnson syndrome: A report of a rare complication for a common imaging agent

Steven-Johnson syndrome (SJS) is a rare condition commonly associated with exposure to antibiotics. We have presented the case of a 76-year-old man with end-stage renal disease who had developed SJS after endovascular thrombectomy of hemodialysis access. He had developed epithelial erosions of the mucosal membranes, hemorrhagic bullae to the palmar and plantar surfaces, and erosions of the genitalia. The findings from biopsies of the lip and palm were suggestive of a drug reaction. He developed SJS three times after exposure to iodinated contrast. The one time he did not develop SJS, he had undergone open thrombectomy with no contrast exposure.

Hypersensitivity Reactions to Iodinated Contrast Media

At present, iodinated contrast media (ICM) are mostly non-ionic, have low osmolality, and are safe. Even if adverse drug reactions (ADRs) occur, most are chemo-toxic symptoms and require only observation or H1 antihistamines. However, rare, unpredictable, and even life-threatening hypersensitivity can still occur. The aim of this review is to summarize the issues that all relevant staff need to know about and be able to respond to. The most significant risk factor for ICM hypersensitivity is a history of ICM hypersensitivity. For high-risk populations, we must cautiously weigh the advantages and disadvantages of premedication and be aware that breakthrough reactions may still occur. The best policy for patients with a history of severe ICM hypersensitivity is to avoid the same ICM. If ICM are inevitable, skin tests, in vitro tests, and drug provocation tests may help to find a feasible alternative that is safer. The severity of the hypersensitivity is correlated with the positivity rate of these tests, so there is no need for further investigations for patients with only mild reactions. We should also keep in mind that even excipients in ICM may induce hypersensitivity. Detailed, standardized documentation is essential for correct diagnosis and the prevention of future occurrence.

Radiocontrast Media Hypersensitivity Reactions in Children

Hypersensitivity reactions to radiocontrast media seem to be rare in children. Furthermore, the use of radiocontrast media in children remains quite safe in terms of the severity of reactions. Since pediatric guidelines are lacking, the diagnostic workup employed in adults could be adapted to children, taking into account that results have not yet been validated in this age group. Specific protocols for risk stratification and management of severe reactions have been proposed so far.

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.

Clinical implication of detecting sensitization to iodinated radiocontrast media in the basophil activation test by flow cytometry

The use of iodinated radiocontrast media is necessary for visualization. A number of patients have adverse effects of various nature and severity when these drugs are administered. Routine allergy tests do not provide adequate diagnosis of reactions to drugs in this group. The aim of this work is to assess the capabilities of the basophil activation test to confirm sensitization to non-ionic iodinated radiocontrast media, as well as to select a safe alternative drug in patients with a burdened history. Basophil activation test by flow cytometry was performed in 184 patients The Nikiforov Russian Centre of Emergency and Radiation Medicine» EMERCOM of Russia and 32 volunteers using ultravist, omnipack, and optiray. The presence of sensitization was assessed based on the basophil activation index, as well as spontaneous and anti-IgE antibody-induced activation of basophils and the population of T-lymphocytes type 2 immune response. The volunteers showed no sensitization to iodinated radiocontrast media. In patients with a medium degree of hypersensitivity reaction in vivo, in vitro sensitization to drugs was detected 4 times more often than in patients with a mild degree (51% versus 13.5%). In patients with systemic reactions to the administration of a known drug, in vitro sensitization was confirmed in 86% of cases, while the frequency of detection of sensitization to drugs did not differ. Spontaneous activation of basophils in patients and type 2 T-lymphocytes were 2 times higher than in volunteers. Patients were more likely to have low (less than 30%) activation of basophils for anti-IgE antibodies. The specificity of the basophil activation test with iodinated radiocontrast media was 100% with a sensitivity of 94.1%. Most patients were able to select a non-sensitizing contrast. Inclusion in the algorithm of spontaneous and anti-IgE antibody-induced activation of basophils and a population of T-lymphocytes type 2 immune response will allow the doctor to carry out a personalized approach to the management of patients with a burdened history.

Inherent clinical properties of non-immediate hypersensitivity to iodinated contrast media

BACKGROUND

Iodinated contrast media (ICM) is a frequently used compound in radiology. Non-immediate hypersensitivity reactions (HSR) appear when a patient leaves the department and usually are undocumented. True hypersensitivity in this group is rarely proved.

METHODS

Single-centre 2014-2018 data were retrospectively analysed. HSR to ICM were classified and investigated according to the time of occurrence (immediate <1 hour, non-immediate >1 hour). ENDA questionnaire and skin tests (prick or intradermal test) were performed according to ENDA/EAACI recommendations.

RESULTS

69 patients with a clinical history of HSR to ICM were identified, 72.46% were females (n = 50). The average age was 56 (SD ± 13.16) years. Non-immediate HSR occurred in 28.99% (n = 20) patients. The suspected culprit drugs were: iodixanol 20% (n = 4), iopromide 5% (n = 1), diatrizoate 10% (n = 2) and iohexol 10% (n = 2). Among non-immediate HSR 96.00% (n = 19) of patients had skin rashes. A statistically significant correlation was found between the clinical symptoms and the type of reaction (p-value <0.05): isolated skin manifestations mostly occurred in non-immediate HSR 75.00% (n = 15). Only 13.04% (n = 9) of all the patients were proved to be allergic to a certain ICM after the proposed diagnostic workup.

CONCLUSIONS

One-third of the hypersensitivity reactions investigated were classified as non-immediate type. Most of them manifested with isolated skin symptoms. The most frequent culprit drug encountered was iodixanol. The overall non-immediate hypersensitivity confirmation rate after diagnostic evaluation was only 15%.

Diagnosing and Managing Patients with Reactions to Radiocontrast Media

Purpose of the review

Iodinated radio contrast media (RCM) belong to the most common elicitors of drug hypersensitivity reactions (HR). Urticaria or anaphylaxis may occur ≤ 1(−6) hour(s) (immediate HR) and exanthems (non-immediate HR) develop > 6 h after application of RCM. Evidence for an immunologic mechanism of RCM HR against the different RCM benzene ring molecules and the benefit of allergological testing in patients with previous hypersensitivity reactions is progressively increasing.

Recent findings

Positive skin tests can confirm allergy in patients with previous reactions to RCM and help to select alternative better tolerated RCMs. Severe hypersensitivity reactions are mainly caused by an allergic mechanism, whereas the majority of non-severe reactions appear to be non-allergic. Skin testing is highly recommended to help identify allergic hypersensitivity reactions and to select alternatives. Using structurally different RCM is more effective than premedication for the prevention of future reactions. Drug provocation tests to RCM have been increasingly used, but are not yet standardized among different centers.

Summary

In patients with previous severe hypersensitivity reactions to RCM, skin testing is recommended. For future RCM-enhanced examinations in patients with previous reactions, structurally different, skin test-negative preparations should be applied. Drug provocation tests do confirm or exclude RCM hypersensitivity or may demonstrate tolerability of alternative RCMs.

Pharmacological prevention of delayed hypersensitivity reactions caused by iodinated contrast media

Background

Delayed hypersensitivity reactions (DHRs) to radiocontrast media (RCM) occur in approximately 0.5–23.0% of patients and are thought to be caused by T cell-mediated mechanisms. However, an optimal pharmacological preventive strategy is not yet established in patients with histories of delayed reactions to RCM.

Objective

We aimed to evaluate the efficacy of pharmacological prevention in patients with histories of delayed reactions to non-ionic low-osmolar RCM when re-exposed to RCM.

Methods

A retrospective review of electronic medical records of 117 patients with previous histories of DHRs to RCM who visited an allergy clinic for the prevention of reactions after the re-exposure to RCM was conducted. The effects of pharmacological prevention were compared according to the symptom scores of previous reactions based on their intensities and durations with electronic medical records (EMRs).

Results

Of the 117 patients who experienced DHRs after RCM injection, we confirmed the outcomes of RCM re-exposure in 101 patients. For pharmacological prevention, 92 patients (91.1%) received steroids before RCM injection and among them, 50 patients (49.5%) received additional steroids after RCM injection. With this pharmacological prevention, patients of symptoms improved or no recurrence, recurrence of similar previous symptoms, and recurrence of worse symptoms were 98 (97.0%), 2 (2.0%), and 1 (1.0%), respectively. The proportions of no recurrence after pharmacological prevention were lower in patients with severe reactions and higher symptom scores.

Conclusion

Pharmacological prevention showed a beneficial effect in most patients with delayed hypersensitivity to RCM. Further investigations are needed to establish an effective protocol for the prevention of delayed reactions to RCM.

Iodine Contrast Complex Rash Responding to Topical Steroids: A Case Report

Patient: Male, 75-year-old

Final Diagnosis: Delayed IV contrast allergic reaction

Symptoms: Rash

Medication:—

Clinical Procedure: —

Specialty: Dermatology

DRESS and AGEP Reactions to Iodinated Contrast Media: A French Case Series

BACKGROUND

Drug reactions with eosinophilia and systemic symptoms (DRESSs) and acute generalized exanthematous pustulosis (AGEP) are potentially severe cutaneous adverse drug reactions.

OBJECTIVE

To describe the clinical findings and sensitization profiles of DRESS and AGEP patients who had been administered iodinated contrast media (ICM).

METHODS

All adult patients in the dermatologist's French Investigators for Skin Adverse Reactions to Drugs (FISARD) network diagnosed with a DRESS or AGEP highly suspected to have been caused by an ICM were included retrospectively.

RESULTS

Thirteen DRESS patients and 19 AGEP patients who had been administered ICM were included, and the median delay in DRESS and AGEP occurrence after ICM administration was short, 4 and 1 days, respectively. Five AGEP patients had systemic involvement. A high cosensitization rate (46%) was observed among the DRESS patients, mainly with beta-lactam antibiotics. Overall, 77% of our patients were sensitized to several ICM. Patch tests identified the suspected ICM for 21 cases (72%). The retrospective nature, the limited number of subjects, the absence of a control group of healthy individuals, and the lack of detailed information on previous exposure to sensitizing drugs are limitations of this study.

CONCLUSIONS

We report a large series of DRESSs and AGEPs related to ICM administration. Skin tests appear useful for diagnosis and potentially to identify alternative ICM.

Probable parenteral and oral contrast-induced Steven Johnson syndrome/toxic epidermal necrolysis

We report a case of contrast-inducted Steven Johnson Syndrome (SJS)/Toxic Epidermal Necrolysis (TEN). The patient had received parenteral iopamidol and oral iohexol five days prior. The patient's chief complaint at the Emergency Department (ED) presentation was shortness of breath and blisters throughout body. Upon arrival, the patient was awake, alert, and oriented with a blood pressure (BP) of 166/68, heart rate (HR) of 117 beats per minute, respiratory rate (RR) of 22 breaths per minute and oxygen saturation of 94% on room air. A review of systems was unremarkable with the exception of chills, fatigue and rash. Physical exam was significant for right eye edema/crusting, hemorrhagic bullae, and maculopapular rash. The patient's initial laboratory results were significant for platelets (PLT) of 549 and absolute neutrophil count (ANC) 8.48 × 10(3)/mcL, neutrophils 84.2%, and lymphocytes 10%. Complete metabolic panel was normal with serum creatinine 0.77 mg/dL. The patient was initially treated with diphenhydramine, methylprednisolone, ondansetron, sodium chloride, lorazepam and oxycodone-acetaminophen. Hemotology/Oncology and Trauma/Burn consult identified possible SJS/TEN and the patient was transferred to another facility for dermatologic/burn follow up.

Gadolinium-based contrast agents: What we learned from acute adverse events, nephrogenic systemic fibrosis and brain retention

BACKGROUND

 Radiologists have been administering gadolinium-based contrast agents (GBCA) in magnetic resonance imaging for several decades, so that there is abundant experience with these agents regarding allergic-like reactions, nephrogenic systemic fibrosis (NSF) and gadolinium retention in the brain.

METHODS

 This review is based on a selective literature search and reflects the current state of research on acute adverse effects of GBCA, NSF and brain retention of gadolinium.

RESULTS

 Due to the frequent use of GBCA, data on adverse effects of these compounds are available in large collectives. Allergic-like reactions occurred rarely, whereas severe acute reactions were very rarely observed. Systemic changes in NSF also occur very rarely, although measures to avoid NSF resulted in a significantly reduced incidence of NSF. Due to gadolinium retention in the body after administration of linear MR contrast agents, only macrocyclic preparations are currently used with few exceptions. Clear clinical correlates of gadolinium retention in the brain could not be identified so far. Although the clinical added value of GBCA is undisputed, individual risks associated with the injection of GBCA should be identified and the use of non-contrast enhanced MR techniques should be considered. Alternative contrast agents such as iron oxide nanoparticles are not clinically approved, but are currently undergoing clinical trials.

CONCLUSION

 GBCA have a very good risk profile with a low rate of adverse effects or systemic manifestations such as NSF. Gadolinium retention in the brain can be minimized by the use of macrocyclic GBCA, although clear clinical correlates due to gadolinium retention in the brain following administration of linear GBCA could not be identified yet.

KEY POINTS

· Acute adverse effects are predominantly mild/moderate, rarely severe reactions occur.. · International guidelines resulted in significant reduction of nephrogenic systemic fibrosis.. · Application of macrocyclic contrast agents minimizes gadolinium retention in the brain..

CITATION FORMAT

· Bäuerle T, Saake M, Uder M. Gadolinium-based contrast agents: What we learned from acute adverse events, nephrogenic systemic fibrosis and brain retention. Fortschr Röntgenstr 2021; 193: 1010 - 1018.

Adverse reactions during procedures: Hypersensitivity to contrast agents and dyes

OBJECTIVE

This review provides an overview of the literature on hypersensitivity reactions during procedures to commonly used contrast agents and dyes. A synthesis of current knowledge on clinical symptoms, epidemiology and risk factors, pathomechanism, and management of hypersensitivity reactions to these substances is presented.

DATA SOURCES

A literature search was conducted through Medline. Included were peer-reviewed articles written in English between 2000 and 2019.

STUDY SELECTIONS

Relevant clinical studies, experimental studies, and review articles have been selected. Additionally, case reports have been included if they carried significant information about rare clinical forms of hypersensitivity reactions, disease mechanisms, or therapy.

RESULTS

An allergological workup is only indicated for patients with a history of immediate (IHR) and nonimmediate hypersensitivity reactions (NIHR) but not for toxic or unrelated adverse events. Skin tests with or without experimental cellular laboratory tests in patients with previous reactions can provide evidence for an allergic mechanism. Positive skin tests indicating allergy are more common in severe reactions. If the adverse event was allergic, skin testing of alternatives is helpful for the selection of other contrast agents for future procedures. Premedication alone may be insufficient in these cases, and breakthrough reactions occur. For nonallergic reactions, change of contrast agent and premedication is often but not always sufficient to suppress reactions.

CONCLUSION

Patients with previous NIHR or IHR, especially moderate and severe IHR, needing potential re-administration of contrast agents should be skin tested to identify an allergic mechanism as well as alternative agents to be used for future procedures.