Oral aspirin challenges in patients with a history of intolerance to single non-steroidal anti-inflammatory drugs

Hypersensitivity reactions to non-steroidal anti-inflammatory drugs: results of an Austrian cohort study

Background

Hypersensitivity to non-steroidal anti-inflammatory drugs (NSAIDs) is the second most common cause of drug hypersensitivity. Despite the importance of NSAIDs in routine analgesia only few studies have systematically addressed the question of tolerability in hypersensitive patients.

Methods

The authors retrospectively analysed 398 patients that were treated at the Department of Dermatology, Kepler University Hospital Linz, Austria, in the period 2012–2016 with a clinical history of NSAID hypersensitivity. Skin tests (skin prick and intracutaneous tests) to common NSAIDs were performed, followed by single-blinded, placebo-controlled drug challenge with either the culprit drug or an alternative NSAID.

Results

A total of 361 patients were subjected to skin testing. Of these, 25 patients (6.3%) showed a positive reaction to the culprit drug. According to the severity of the reaction in the medical history, 87 patients were exposed orally to the culprit drug (oral provocation test, OPT) after negative skin test and 255 patients received OPT with alternative NSAIDs according to established protocols. OPT with the culprit drug resulted in hypersensitivity reactions in 12 patients (13.79%). In terms of alternative NSAID testing, the three most commonly tested drugs were lornoxicam (192 OPTs), acetaminophen (156 OPTs) and celecoxib (133 OPTs) with tolerability rates in respectively 88.54% (hypersensitivity reactions, 11.46%), 92.31% (hypersensitivity reactions, 7.69%) and 91.73% (hypersensitivity reactions, 8.27%) of cases.

Conclusion

OPT with alternative NSAIDs are useful in patients with NSAID hypersensitivity as tolerability varies between the individual substances.

Multiple Drug Intolerance Syndrome: An Underreported Distinct Clinical Entity

Aim:

Multiple drug intolerance syndrome (MDIS) is a unique clinical entity distinct from other drug hypersensitivity syndromes. The aim of this review was to critically appraise the various aspects of MDIS.

Methods

A review was conducted to search for the causes, mechanism, clinical features, and management of MDIS.

Results

The most common cause of MDIS is antibiotics followed by non-steroidal anti-inflammatory drugs (NSAIDs). Although some non-specific immunological mechanisms are involved, the immunological tests for MDIS are negative. Rashes, gastrointestinal reflux, headache, cough, muscle ache, fever, dermatitis, hypertension, and psychiatric symptoms are the usual manifestations. Treatment is mostly symptomatic with the withdrawal of the offending drug. Drug re-challenges and desensitization may be required for the management of this syndrome.

Conclusion

MDIS occurs by a nonimmune mechanism which requires a prompt withdrawal of the offending drug(s), and in some cases may require drug re-challenge and desensitization.

NSAIDs-hypersensitivity often induces a blended reaction pattern involving multiple organs

Non-steroidal anti-inflammatory drugs (NSAIDs)-induced hypersensitivity reactions are classified by the European Network on Drug Allergy (ENDA) as either cross-reactive or selective. The former is the most frequent type and includes patients with exclusively respiratory symptoms (NSAIDs-exacerbated respiratory disease, NERD) or exclusively cutaneous symptoms: NSAIDs-induced urticaria/angioedema (NIUA); and NSAIDs-exacerbated cutaneous disease (NECD). However, although not reflected in the current classification scheme (ENDA), in clinical practice a combination of both skin and respiratory symptoms or even other organs such as gastrointestinal tract symptoms (mixed or blended reactions) is frequently observed. This entity has not been sufficiently characterised. Our aim was to clinically characterize blended reactions to NSAIDs, comparing their clinical features with NERD and NIUA. We evaluated patients with symptoms suggestive of hypersensitivity to NSAIDs who attended the Allergy Unit of the Regional University Hospital of Malaga (Malaga, Spain) between 2008 and 2015. We included 880 patients confirmed as cross-reactive based on clinical history, positive nasal provocation test with lysine acetylsalicylate (NPT-LASA), and/or positive drug provocation test (DPT) with acetylsalicylic acid (ASA), who were classified as blended (261; 29.6%), NERD (108; 12.3%) or NIUA (511; 58.1%). We compared symptoms, drugs, underlying diseases and diagnostic methods within and between groups. Among blended patients the most common sub-group comprised those developing urticaria/angioedema plus rhinitis/asthma (n = 138), who had a higher percentage of underlying rhinitis (p < 0.0001) and asthma (p < 0.0001) than NIUA patients, showing similarities to NERD. These differences were not found in the sub-group of blended patients who developed such respiratory symptoms as glottis oedema; these were more similar to NIUA. The percentage of positive NPT-LASA was similar for blended (77%) and NERD groups (78.7%). We conclude that blended reactions are hypersensitivity reactions to NSAIDs affecting at least two organs. In addition to classical skin and respiratory involvement, in our population a number of patients also develop gastrointestinal symptoms. Given the high rate of positive responses to NPT-LASA in NERD as well as blended reactions, we suggest that all patients reporting respiratory symptoms, regardless of whether they have other associated symptoms, should be initially evaluated using NPT-LASA, which poses less risk than DPT.

Predictive value of a negative oral provocation test in patients with hypersensitivity to analgesics

INTRODUCTION

Nonsteroidal anti-inflammatory drugs (NSAIDs) take first or second place as the cause of drug-induced hypersensitivity reactions. The oral provocation test (OPT) is a gold standard for the diagnosis of NSAID hypersensitivity. We investigated which analgesics patients took after a negative OPT and determined the proportion of patients that experienced a hypersensitivity reaction despite a negative OPT.

METHODS

We selected 115 patients (67.8% female, age 54.9 ± 16.7 years) with a negative aspirin OPT and a convincing history of immediate hypersensitivity to aspirin or NSAIDs. In a telephone survey, we identified the analgesics taken after the OPT and possible adverse events.

RESULTS

The mean follow-up time was 5.1 ± 2.0 years. All subjects needed at least one analgesic drug. Despite the negative outcome of the aspirin OPT, only 33.9% of subjects took aspirin and 0.9% had a hypersensitivity reaction. The negative predictive value (NPV) of the aspirin OPT was 97.4%. Overall, 16 (13.9%) subjects experienced a hypersensitivity reaction, 12 of which occurred after taking a drug not tested with the OPT. The NPV of the OPT for all NSAIDs was 96.4%.

CONCLUSIONS

Our results support the available data that most subjects do not re-take the tested drug regardless of the high NPV of the OPT.

Rapid Aspirin Challenge in Patients with Aspirin Allergy and Acute Coronary Syndromes

Aspirin allergy in a patient with acute coronary syndrome represents one of the more urgent challenges an allergist may face. Adverse reactions to aspirin are reported in 1.5% of patients with coronary artery disease. A history of adverse reaction to aspirin often leads to unnecessary withholding of this medication or use of alternative antiplatelet therapy which may be inferior or more costly. Aspirin therapy has been shown to reduce morbidity and mortality in patients with coronary artery disease. Rapid aspirin challenge/desensitization in the aspirin allergic patient has been consistently shown to be both safe and successful in patients with acute coronary syndromes.

Evaluation of hypersensitivity reactions to nonsteroidal anti-inflammatory drugs according to the latest classification

BACKGROUND/AIM

The consensus document for hypersensitivity reactions to nonsteroidal anti-inflammatory drugs (NSAIDs) proposed by the European Network for Drug Allergy (ENDA) interest group (2011) was revised in 2013. We aimed to evaluate the usability of the latest NSAID hypersensitivity classification of ENDA.

METHOD

A total of 370 patients with a history of hypersensitivity reactions to NSAIDs among the 1250 outpatients referred for suspected drug allergy between July 2013 and June 2014 were evaluated, and 308 patients who were confirmed as having NSAID hypersensitivity were included in this study. After confirming the diagnosis, a single-blind placebo-controlled drug provocation test was performed with aspirin or diclofenac to categorize the patients according to the ENDA classification. The reactions not meeting the ENDA classification criteria were grouped as blended reactions.

RESULTS

Among the 308 patients (224 female, mean age 42.12 ± 13.24), the leading cause of hypersensitivity reactions was metamizol (30.5%) followed by aspirin (30.2%). The most common NSAID hypersensitivity subgroup was SNIUAA (46.4%) and the least common type was SNIDR (1.6%). Cross-reactivity was identified in 50.3% of the patients. In five patients (1.6%), the hypersensitivity reactions to NSAIDs did not meet the ENDA classification: Three patients experienced anaphylaxis with different NSAIDs, one patient encountered anaphylaxis with one NSAID and urticaria with other NSAIDs, and the last patient had angioedema with different NSAIDs.

CONCLUSION

The latest ENDA classification for NSAID hypersensitivity is generally a practical and useful instrument for clinicians. We only point out that anaphylaxis with different NSAIDs can be seen in a small group of patients.

Hypersensitivity to non-steroidal anti-inflammatory drugs (NSAIDs): classification of a Danish patient cohort according to EAACI/ENDA guidelines

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) are reported to be the second most common cause of drug hypersensitivity. In 2011, experts from the EAACI/ENDA group and GA(2)LEN proposed a new classification system for NSAID hypersensitivity. The aim of this study was to classify a patient cohort with a history of NSAID hypersensitivity according to this system.

METHODS

Patients with a clinical history of NSAID hypersensitivity referred to the Allergy Centre, Odense University Hospital between 2002 and 2011 and evaluated with oral provocation tests (OPTs) were included in the study. Medical records were retrospectively investigated with respect to the culprit NSAID(s), underlying diseases and symptoms at the primary reaction and during oral provocation tests (OPTs). Data was supplemented with a questionnaire. Classification according to EAACI guideline was based on these findings.

RESULTS

In total 149 patients were included. Of those, 39 patients (26.2%) had a positive OPT. Twenty-nine patients were classified as cross-reactive responders and 9 patients as single NSAID responders after positive OPTs with the culprit NSAID, but not to acetylsalicylic acid. All single NSAID responders reacted to non-pyrazolone drugs. Only one patient could not be classified according to the EAACI/ENDA system. An overlap between respiratory and cutaneous symptoms was found in 15/39 (38%) of patients.

CONCLUSIONS

All but one of our patients could be classified according to the EAACI classification system. Overlaps between different classes may occur much more commonly than expected.

Multiple nonsteroidal anti-inflammatory drug-induced cutaneous disease: what differentiates patients with and without underlying chronic spontaneous urticaria?

BACKGROUND

Multiple nonsteroidal anti-inflammatory drug (NSAID) cutaneous reactors may be otherwise normal or have underlying chronic spontaneous urticaria (CSU). This study compared these two phenotypes of NSAID-hypersensitive subjects.

METHODS

A total of 97 multiple NSAID reactors underwent oral challenges with paracetamol, etoricoxib and tramadol. Atopic status was investigated in all patients, and autoreactivity was ascertained in some cases as well. Otherwise normal multiple NSAID reactors were reevaluated after 1-5 years in order to detect their proneness to CSU.

RESULTS

At the first visit, 41 patients had CSU and 56 had multiple NSAID intolerance without any underlying cutaneous disease. Altogether, 22, 10 and 6% of patients did not tolerate paracetamol, etoricoxib and tramadol, respectively, on oral challenge. Intolerance to these alternative drugs showed a strong association (p < 0.01 with all combinations). The two subgroups of patients did not show any difference in terms of mean age, gender distribution, prevalence of atopic diseases, prevalence of single offending NSAIDs and prevalence of intolerance to paracetamol, etoricoxib or tramadol on oral challenge. In all, 20% of multiple NSAID reactors without CSU at presentation developed CSU between 6 months and 5 years after the initial clinical evaluation.

CONCLUSIONS

Multiple NSAID cutaneous reactors with or without CSU seem identical from a clinical point of view, and some of the latter group show a propensity to acquire the former phenotype over time. A subset of patients apparently identical to the general population of multiple NSAID reactors also react to drugs exerting little or no cyclooxygenase-1 enzyme inhibition and might represent a distinct phenotype of NSAID-hypersensitive patients possibly characterized by a different underlying pathogenesis.

Classification and practical approach to the diagnosis and management of hypersensitivity to nonsteroidal anti-inflammatory drugs

Hypersensitivity reactions to aspirin (acetylsalicylic acid) and other nonsteroidal anti-inflammatory drugs (NSAIDs) constitute only a subset of all adverse reactions to these drugs, but due to their severity pose a significant burden to patients and are a challenge to the allergist. In susceptible individuals, NSAIDs induce a wide spectrum of hypersensitivity reactions with various timing, organ manifestations, and severity, involving either immunological (allergic) or nonimmunological mechanisms. Proper classification of reactions based on clinical manifestations and suspected mechanism is a prerequisite for the implementation of rational diagnostic procedures and adequate patient management. This document, prepared by a panel of experts from the European Academy of Allergy and Clinical Immunology Task Force on NSAIDs Hypersensitivity, aims at reviewing the current knowledge in the field and proposes uniform definitions and clinically useful classification of hypersensitivity reactions to NSAIDs. The document proposes also practical algorithms for the diagnosis of specific types of NSAIDs hypersensitivity (which include drug provocations, skin testing and in vitro testing) and provides, when data are available, evidence-based recommendations for the management of hypersensitive patients, including drug avoidance and drug desensitization.

Clinical management of patients with a history of urticaria/angioedema induced by multiple NSAIDs: an expert panel review

Nonsteroidal anti-inflammatory drugs (NSAIDs) represent one of the most frequent causes of drug-induced urticaria/angioedema worldwide. Recent review articles have classified patients experiencing NSAID-induced urticaria/angioedema into different categories, including single reactors, multiple reactors, and multiple reactors with underlying chronic urticaria. Each of these categories requires a different clinical approach. The present article, written by a panel of experts, reports the main recommendations for the practical clinical management of patients with a history of urticaria/angioedema induced by multiple NSAID based on current knowledge.

Response to a selective COX-2 inhibitor in patients with urticaria/angioedema induced by nonsteroidal anti-inflammatory drugs

BACKGROUND

In subjects with hypersensitivity reactions with cross-intolerance to nonsteroidal anti-inflammatory drugs (NSAIDs), tolerance to selective COX-2 inhibitors has not been evaluated in large series of well-phenotyped cases.

METHODS

We evaluated 252 patients with urticaria and/or angioedema caused by hypersensitivity owing to cross-intolerance to NSAIDs. In addition to the clinical history, diagnosis was confirmed by provocation to an alternative NSAID. Two groups were considered: (A) patients with cross-intolerance to NSAIDs and intolerance to paracetamol and (B) patients with cross-intolerance to NSAIDs and good tolerance to paracetamol. Etoricoxib was administered to Group A patients and to a representative sample of Group B patients. In the event of a positive response, serum tryptase levels were determined and skin biopsy was performed in five patients in each group.

RESULTS

Ibuprofen was the most commonly implicated drug, followed by acetylsalicylic acid (ASA). Urticaria was the most common manifestation, followed by angioedema. Most of the patients developed symptoms within 1 h. Twenty-five percent in Group A (n = 47) and 6% in Group B (n = 50) were intolerant to etoricoxib. Skin biopsy showed mast cell activation with the release of tryptase to the extracellular space but without the increase in serum tryptase levels.

CONCLUSION

Selective COX-2 inhibitors may be unsafe in subjects with urticaria and/or angioedema caused by hypersensitivity reactions to NSAIDs with cross-intolerance if they are intolerant to paracetamol. A quarter of patients who were intolerant to this drug were also intolerant to etoricoxib. In subjects with hypersensitivity to NSAIDs and intolerance to paracetamol, selective COX-2 inhibitors should be administered as a controlled, incremental dose provocation test to assess tolerance.

Hypersensitivity to nonsteroidal anti-inflammatory drugs (NSAIDs) - classification, diagnosis and management: review of the EAACI/ENDA(#) and GA2LEN/HANNA*

Nonsteroidal anti-inflammatory drugs (NSAIDs) are responsible for 21-25% of reported adverse drug events which include immunological and nonimmunological hypersensitivity reactions. This study presents up-to-date information on pathomechanisms, clinical spectrum, diagnostic tools and management of hypersensitivity reactions to NSAIDs. Clinically, NSAID hypersensitivity is particularly manifested by bronchial asthma, rhinosinusitis, anaphylaxis or urticaria and variety of late cutaneous and organ-specific reactions. Diagnosis of hypersensitivity to a NSAID includes understanding of the underlying mechanism and is necessary for prevention and management. A stepwise approach to the diagnosis of hypersensitivity to NSAIDs is proposed, including clinical history, in vitro testing and/or provocation test with a culprit or alternative drug depending on the type of the reaction. The diagnostic process should result in providing the patient with written information both on forbidden and on alternative drugs.

Basophil responsiveness and clinical picture of acetylsalicylic acid intolerance

BACKGROUND

Exposure to acetylsalicylic acid (ASA) may exacerbate respiratory or skin diseases or induce anaphylactoid reactions in apparently healthy individuals. We wanted to evaluate specific responsiveness of basophils to ASA in correlation with the clinical picture.

METHODS

We performed a prospective single-blind study of 59 subjects involved in clinical evaluation and/or ASA provocation testing. Whole blood basophils were stained with anti-CD63/CD123/HLA-DR mAbs after stimulation with 0.25 or 1 mg/ml ASA.

RESULTS

We found that 40 subjects were ASA tolerant and 19 were ASA intolerant. Both groups had comparable manifestations of asthma and/or rhinitis (13 in the tolerant and 9 in the intolerant group). Intolerant subjects showed significantly higher basophil responsiveness to ASA in comparison to tolerant subjects, which was concentration-dependent in both groups. The ratio between responses at 1 mg/ml of ASA and at baseline (activation index) was analyzed according to the clinical picture. We demonstrate that the activation index was higher only in the intolerant subjects with anaphylactoid reactions, but not in a subgroup of subjects with asthma/rhinitis. The ROC calculations show that the optimal threshold activation index was more than 2.18. The sensitivity was 80% and the specificity was 83% in the subgroup with anaphylactoid reactions. In the asthma/rhinitis subgroup, the sensitivity was 78% and the specificity was 50%.

CONCLUSIONS

Our study demonstrates that there is a significantly higher in vitro basophil response to ASA in intolerant as compared to tolerant subjects. ROC analyses suggest that this measurement might only have a diagnostic value in subjects without asthma and/or rhinitis.

NSAID hypersensitivity (respiratory, cutaneous, and generalized anaphylactic symptoms)

Adverse reactions to drugs have been classified as predictable (related to the pharmacologic actions of the drug) and unpredictable (related to the individual's immunologic response or genetic susceptibility). The term "drug hypersensitivity" refers to the symptoms or signs initiated by an exposure to a drug at a dose normally tolerated by nonhypersensitive persons. In this article, the current knowledge on hypersensitivity reactions to nonsteroidal antiinflammatory drugs is discussed.

Predictive Value of Autologous Plasma Skin Test for Multiple Nonsteroidal Anti-Inflammatory Drug Intolerance

BACKGROUND

Recent studies show that patients with multiple nonsteroidal anti-inflammatory drug (NSAID) intolerance are frequently characterized by autoreactivity; this can be detected by autologous serum skin test (ASST).

OBJECTIVE

To assess whether the autologous plasma skin test (APST), a test that was recently shown to be more sensitive than ASST, may be usefully employed as a predictive test for multiple NSAID intolerance in patients with a history of single NSAID intolerance.

METHODS

Thirty otherwise normal adults with a history of acute urticaria following the ingestion of one single NSAID underwent an APST before being challenged with a COX-1-inhibiting NSAID other than the offending drug.

RESULTS

Sixteen patients experienced urticaria following the ingestion of the alternative NSAID and were therefore classified as multiple NSAID reactors; all 16 (100%) scored positive on APST. In contrast only 3/14 patients finally classified as single NSAID reactors were positive on APST (p < 0.001). The positive and negative predictive value of APST for multiple NSAID intolerance were 86 and 100%, respectively.

CONCLUSION

In patients with a history of acute urticaria induced by a single NSAID APST can be usefully employed to detect patients that are prone to react to NSAID other than the original offending one.

Safety of selective cyclooxygenase-2 inhibitors and a basic non-steroidal anti-inflammatory drug (NSAID) in Japanese patients with NSAID-induced urticaria and/or angioedema: Comparison of meloxicam, etodolac and tiaramide

The identification of a safe and reliable alternative for patients with non-steroidal anti-inflammatory drug (NSAID)-induced urticaria/angioedema is a frequent problem for dermatologists and other practitioners. Cyclooxygenase-2 (COX-2) inhibitors have been reported to be safe for NSAID-intolerant patients from the US and Europe but not all of them have yet been approved for use in Japan. It was our objective to investigate the clinical manifestations of oral NSAID challenges in Japanese patients with histories of urticaria and/or angioedema after the intake of NSAIDs and to find safe alternative drugs, including COX-2 inhibitors and a basic anti-inflammatory drug. Twenty subjects suspected NSAID-induced urticaria/angioedema from histories were included in a double-blind or single-blind, placebo-controlled oral challenge protocol using NSAIDs. Skin prick tests using NSAIDs, which were dissolved in saline, were conducted. The mean age of the patients was 37.3 years; 14 patients were female. The results of other challenge tests showed that the most frequently intolerated drugs was loxoprofen (100%), followed by acetyl salicylic (94.4%), etodolac (53.3%), dicrofenac (50%), acetaminophen (38.5%), meloxicam (33%), and tiaramide (21.4%). Urticaria and angioedema were induced after aspirin intake in 83.3% and 22.2% of patients, respectively, whereas an asthmatic response was seen in 5.6%. Skin prick tests with NSAIDs were 100% negative. This study showed that among the NSAIDs that are available in Japan and that were investigated in this study, tiaramide, which does not inhibit COX, is the relatively safe alternative drug for Japanese patients with NSAID-induced urtiacaria and/or angioedema. Furthermore, meloxicam seems to be better tolerated than etodolac between two selective COX-2 inhibitors.

Tolerance to coxibs in patients with intolerance to non-steroidal anti-inflammatory drugs (NSAIDs): a systematic structured review of the literature

Adverse events triggered by non-steroidal anti-inflammatory drugs (NSAIDs) are among the most common drug-related intolerance reactions in medicine; they are possibly related to inhibition of cyclooxygenase-1. Coxibs, preferentially inhibiting cyclooxygenase-2, may therefore represent safe alternatives in patients with NSAID intolerance. We reviewed the literature in a systematic and structured manner to identify and evaluate studies on the tolerance of coxibs in patients with NSAID intolerance. We searched MEDLINE (1966–2006), the COCHRANE LIBRARY (4th Issue 2006) and EMBASE (1966–2006) up to December 9, 2006, and analysed all publications included using a predefined evaluation sheet. Symptoms and severity of adverse events to coxibs were analysed based on all articles comprising such information. Subsequently, the probability for adverse events triggered by coxibs was determined on analyses of double-blind prospective trials only. Among 3,304 patients with NSAID intolerance, 119 adverse events occurred under coxib medication. All adverse events, except two, have been allergic/urticarial in nature; none was lethal, but two were graded as life-threatening (grade 4). The two non-allergic adverse events were described as a grade 1 upper respiratory tract haemorrhage, and a grade 1 gastrointestinal symptom, respectively. In 13 double-blind prospective studies comprising a total of 591 patients with NSAID intolerance, only 13 adverse reactions to coxib provocations were observed. The triggering coxibs were rofecoxib (2/286), celecoxib (6/208), etoricoxib (4/56), and valdecoxib (1/41). This review documents the good tolerability of coxibs in patients with NSAID intolerance, for whom access to this class of drugs for short-term treatment of pain and inflammation is advantageous.

Clinical management of adult patients with a history of nonsteroidal anti-inflammatory drug-induced urticaria/angioedema: update

In the large majority of previous studies, patients with a history of acute urticaria induced by nonsteroidal anti-inflammatory drugs (NSAIDs) seeking safe alternative drugs have undergone tolerance tests uniquely with compounds exerting little or no inhibitory effect on the cyclooxygenase 1 enzyme. In light of recently published studies, however, this approach seems inadequate and should be changed. The present article critically reviews the clinical management of patients presenting with a history of urticaria induced by a single NSAID or multiple NSAIDs and suggests a simple, updated diagnostic algorithm that may assist clinicians in correctly classifying their patients.

Use of ketoprofen oral challenges to detect cross-reactors among patients with a history of aspirin-induced urticaria

BACKGROUND

In patients with a history of urticaria induced by a single nonsteroidal anti-inflammatory drug (NSAID), advising elimination of all drugs that inhibit cyclooxygenase 1 (COX-1) can lead to unnecessary avoidance of useful NSAIDs.

OBJECTIVE

To classify patients with a history of aspirin-induced urticaria as cross-reactors or single-drug reactors by oral challenges with another strong COX-1 inhibitor, namely, ketoprofen.

METHODS

Forty otherwise healthy patients with a history of acute urticaria after the ingestion of aspirin underwent single-blind, placebo-controlled oral challenges with ketoprofen. In patients who did not tolerate ketoprofen, tolerance tests with drugs exerting either COX-1 inhibition at high doses (acetaminophen and nimesulide) or no COX-1 inhibition at therapeutic doses (rofecoxib and tramadol) were performed.

RESULTS

In 24 patients (60%), ketoprofen induced urticaria that was controlled by an intravenous antihistamine; 18 (75%) of the 24 patients reacted after the first provocative dose. On subsequent challenges, 3 (38%) of 8 ketoprofen reactors did not tolerate nimesulide, whereas acetaminophen tramadol and rofecoxib were tolerated by 18 of 18, 14 of 14, and 16 of 16 ketoprofen reactors, respectively. Three ketoprofen reactors reported the onset of spontaneous recurrent urticaria 1 to 3 years after the challenge tests.

CONCLUSION

In patients with a history of urticaria induced by a single NSAID, oral challenges with alternative COX-1 inhibitors are helpful in detecting whether they are true single-NSAID reactors; weak COX-1 inhibitors should be challenged subsequently only in those who show multiple-NSAID intolerance.