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The authors reflects on the use of new diagnostic tool called basophil activation test (BAT) for drug allergy. They state that the routine use of the tool could increase the sensitivity of diagnostic work-ups, therefore, it reduces the need for drug provocation tests. They stress that there is an evidence that the BAT can contribute to the diagnosis of anaphylactic reactions due to several drugs.

Summary Background Proven IgE or T-cell mediated drug hypersensitivity reactions ( DHRs) seem less common in children compared with adults. However, this has never been proved by data. Objective To determine and compare proven DHR prevalence in children and adults. Methods Using the DAHD ( D rug A llergy and H ypersensitivity D atabase) cohort, children with proven DHRs were compared with adults. The international EAACI- ENDA recommendations were followed. Patients were divided into four groups: index reaction and test during childhood ( C/C), index reaction at childhood and test at adulthood ( C/A), index reactions at childhood and adulthood and test at adulthood ( CA/A), index reaction and test at adulthood ( A/A). Results A total of 3275 patients (67.9% female), comprising a total of 4370 patient-episodes, were evaluated (74.5% belonged to the A/A group). Prevalence of positive tests was 15.2% (95% CI, 14.1-16.2) for all tested classes, 10.6% (8.3-13.0) for C/C, 10.6% (7.5-13.6) for C/A, 22.1% (12.8-31.3) for CA/A and 16.5% (15.2-17.8) for A/A. The prevalence was lower in group C/C compared with groups A/A ( P < 0.0001) and CA/A ( P = 0.003). It was also lower in group C/A compared with the two latter groups (respectively P = 0.003 and P = 0.005). Significant differences were found for maculopapular exanthemas only, and not for urticaria/angiœdema and anaphylaxis. The difference was mainly observed with β-lactams and not for NSAIDs. Conclusion and Clinical Relevance Suspicions of DHRs are less likely to be confirmed in children. [ABSTRACT FROM AUTHOR]

Background Several studies have shown that skin tests are useful tools for the diagnosis of iodinated contrast medium (ICM) allergy, but the real number of false negative results is not known. Objective To evaluate the negative predictive value of ICM skin tests. Material and Methods One hundred and fifty-nine patients tested in our department because of a previous ICM reaction over the last 9 years were called and asked standardized questions about ICM re-exposure. Results Twenty-nine patients had been re-exposed to ICM. There were 20 (69.0%) females and the median age was 55 (34–60) years. The median time interval between the reaction and skin testing was 11.9 (1.6–21.5) years. Twenty-four patients (82%) had an immediate reaction, four a non-immediate (13.8%) reaction and no data were available for one patient. Two patients had positive ICM skin tests previously and were re-exposed to a negatively skin-tested ICM and did not react. Only two patients presented a mild reaction during ICM re-injection: one immediate (generalized urticaria lasting for 3 days) and one non-immediate maculopapular reaction. The patient with urticaria was re-tested and re-challenged (negative). The other patient was unable to return for re-testing. Conclusion Skin testing for ICM hypersensitivity has a negative predictive value of 96.6% (95% CI: 89.9–103.2) and none of the reactions in skin-test-negative patients were severe. Multi-centric large surveys are still needed for confirmation. Cite this as: S. Caimmi, B. Benyahia, D. Suau, L. Bousquet-Rouanet, D. Caimmi, P.-J. Bousquet and P. Demoly, Clinical & Experimental Allergy, 2010 (40) 805–810. [ABSTRACT FROM AUTHOR]

Background β-lactams continue to remain the most commonly involved drug family in allergic drug reactions. They are often essential and there is a cost-effective and favourable risk-benefit ratio for the exploration of all suspicions of β-lactam allergy. A firm diagnosis is always based on skin tests and sometimes on provocation tests. Recommendations have been published by allergy societies and distinguished scientists but they are not always concordant and can lead to some confusion for the practicing allergologist. The situation has even worsened since the world wide withdrawal of these penicillin determinants and since the predominance of amoxicillin and cephalosporin prescriptions in most countries. Objective – Method In a recent article, it was stated that patients with a penicillin allergy history and negative skin tests to major and minor penicillin determinants are at a low risk of relapse (0–5%) when receiving a β-lactam. In this paper, our Drug Allergy and Hypersensitivity Database, a cohort database, was used to demonstrate that this statement is false. Standardized European Network for Drug Allergy questionnaires, skin test and challenge procedures were followed. Results One-thousand two-hundred and eighteen subjects, 69.8% of female, 51.7% of atopics, were included. 21.1% had a true β-lactam allergy confirmed by skin tests (178, 69.3%) or by drug provocation (79, 30.7%). 17.4% of the patients with negative skin tests to major and minor penicillin determinants were positive for a β-lactam. Conclusion In the diagnosis of β-lactams allergy, if all skin tests are negative, skin tests with other determinants and provocation tests under strict surveillance are mandatory. [ABSTRACT FROM AUTHOR]

Background Poorly documented self-reported drug allergy (DAll) is a frequent problem in daily clinical practice and has a considerable impact on prescription choices. The diagnostic work-up of drug hypersensitivity (DHs) allows a better classification of the reactions and provides patients with more reliable information and recommendations for future treatments. Objective To assess the prevalence of self-reported adverse drug reactions (ADRs) and DAll in a paediatric population and to investigate children reporting suspected DAll in order to achieve a firm diagnosis. Design The first phase was based on a cross-sectional survey assessing the life occurrence of ADRs and self-reported DAll carried out at the outpatient clinic of a paediatric hospital. The second phase was based on the diagnostic work-up in children with parent-reported DAll, including detailed anamnesis and in vitro and in vivo investigations (skin and provocation tests). Participants One thousand four hundred and twenty-six parents responded to the initial survey. Sixty of the 67 patients with reported DAll were evaluated at the allergy clinic. Results The prevalences of self-reported ADRs and DAll were 10.2% and 6.0%, respectively. Most of the suspected allergic reactions were non-immediate cutaneous events attributable to β-lactam antibiotics and occurred in very young children. Thirty-nine of the 60 patients consulting for evaluation had a plausible clinical history and were recommended further investigation. DHs was diagnosed in three children only, based on positive responses in skin ( n=1) and oral provocation ( n=2) tests. Conclusion ADRs are frequently reported in children, and many children are classified as having a DAll. After complete evaluation, only a few of these reactions can be attributed to DHs and DAll. Most of the patients (94% in this study) could actually tolerate the initially suspected drug. [ABSTRACT FROM AUTHOR]

To estimate the prevalence of self-reported drug allergy in adults.Cross-sectional survey of a general adult population from Porto (all of whom were living with children involved in the International Study of Asthma and Allergies in Childhood–phase three), during the year 2002, using a self-administered questionnaire.The prevalence of self-reported drug allergy was 7.8% (181/2309): 4.5% to penicillins or otherβ-lactams, 1.9% to aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs) and 1.5% to other drugs. In the group‘allergic toβ-lactams’, the most frequently implicated drug was penicillin G or V (76.2%) followed by the association of amoxicillin and clavulanic acids (14.3%). In the group‘allergic to NSAIDs’, acetylsalicylic acid (18.2%) and ibuprofen (18.2%) were the most frequently identified drugs, followed by nimesulide and meloxicam. Identification of the exact name of the involved drug was possible in less than one-third of the patients, more often within the NSAID group (59.5%). Women were significantly more likely to claim a drug allergy than men (10.2% vs. 5.3%). The most common manifestations were cutaneous (63.5%), followed by cardiovascular symptoms (35.9%). Most of the reactions were immediate, occurring on the first day of treatment (78.5%). Only half of the patients were submitted to drug allergy investigations. The majority (86.8%) completely avoided the suspected culprit drug thereafter.The results showed that self-reported allergy to drugs is highly prevalent and poorly explored. Women seem to be more susceptible.β-lactams and NSAIDs are the most frequently concerned drugs. [ABSTRACT FROM AUTHOR]

Summary Background Hypersensitivity to paracetamol (acetaminophen) is rare and very few clinical data are available in the literature. Materials and methods Eighty-four patients (28 males and 56 females, 5–70 years old) with a suspicion of paracetamol hypersensitivity were referred to our drug allergy clinic between May 1996 and May 2000. The reaction had occurred 1–96 months prior to the consultation. Single-blinded placebo-controlled oral challenges were carried out in 82 patients, under strict hospital surveillance. Results Most of the patients experienced skin eruptions 82/84 (97.6%), with 10 cases of anaphylactic shock (11.9%). Twenty-six (30.9%) reactions were immediate (occurring within the first hour after drug intake), 53 (63.1%) non-immediate and five could not remember. Oral provocation tests (OPT) demonstrated drug hypersensitivity in 11 patients only. The two patients not tested (due to a history of life-threatening reaction) were included in the positive group. Thus, 13 (15.5%) patients had paracetamol hypersensitivity and 71 (84.5%) had not. All the 13 positive patients had skin eruptions, five with anaphylactic shock. 9/13 had immediate reactions. Using OPT, 10 out of 11 had the same clinical reaction but more delayed. In both groups, whether hypersensitive to paracetamol or not: atopy was similar (7/13–53.8% and 31/71–43.7%), sex ratio was not different (M/F 0.3 and 0.5), 3/13 (23.1%) and 0/71 (0%) had aspirin/ibuprofen hypersensitivity. Conclusion The clinical history of paracetamol (acetaminophen) hypersensitivity is rarely sufficient to set a firm diagnosis and only OPT can confirm this. Careful OPT reproduces the same symptoms (not more severe in our hands) with the same or slightly more delayed chronology. Atopy and sex are not risk factors. [ABSTRACT FROM AUTHOR]