Challenging dogmas: Intravenous versus oral beta-lactam antibiotic provocation tests.

Background: Drug provocation tests (DPT) are considered the gold standard procedure to ascertain the diagnosis of beta-lactam (BL) allergy. Regarding route of administration, current recommendations prioritize oral challenges, considering them safer, and reserving the intravenous route for drugs for which this is the only formulation. Objective: To compare in terms of tolerance and safety two protocols of BL DPT, using an oral protocol (OR-DPT) and an intravenous protocol (IV-DPT). Methods: A descriptive, retrospective study was performed, including adult patients who underwent IV-DPT or OR-DPT for suspected immediate or delayed hypersensitivity to BL antibiotics, over a period of 4 years (between January 2018 and December 2021). Demographical data, index hypersensivity reactions' characteristics and tolerance to DPT were reviewed. Results: A total of 1036 patients underwent DPT, mean age of 56.8 (standard deviation, SD, 17.8) years, 655 were women (63.2%). Immediate drug hypersensitivity reactions (DHR) had occurred in 564 of patients (54.4%). OR-DPT were performed in 439 (42.4%) and IV-DPT in 597 (57.6%). The frequency of reactions during DPT, regardless of the route used, was low (3.6%): only 16 (3.6%) in OR-DPT and 21 (3.5%) in IV-DPT. From IV-DPT, 16 out 21 DHR during DPT were immediate compared with 4 out of 16 in OR-DPT. Adjusted relative risk of developing a hypersensitivity reaction during IV-DPT versus OR-DPT was 1.13 (95% confidence interval (CI)0.57-2.22). Conclusion: The results suggest that OR-DPT and IV-DPT are both safe procedures when adequately performed. However, IV-DPT protocols showed a higher rate of immediate DHR during DPT probably due to the selection of basal high-risk patients to undergo IV-DPT. In conclusion, IV-DPT may be considered as an option for challenges in drug-allergy studies, entailing a precise administration.

Pregabalin-induced delayed cutaneous hypersensitivity reaction occurring after 40 days of use: a case report.

Pregabalin is the first-line treatment for neuropathic pain. Cases of cutaneous hypersensitivity reactions caused by pregabalin generally occur within 2 weeks of initiating medication. We report a rare case of a delayed cutaneous hypersensitivity reaction caused by pregabalin, which was confirmed by a drug provocation test. A 72-year-old man with severe herpes zoster neuralgia developed maculopapular drug eruption covering 80% to 90% of his total body surface area after 40 days of combined multidrug analgesia. A drug provocation test for pregabalin was positive. The time interval between initiating medication and the onset of the patient's rash was the longest and he also had the largest area of skin affected compared with patients with a similar condition in previous related reports. Remaining vigilant for possible adverse cutaneous hypersensitivity reactions during treatment is important because of the long-term course of pregabalin treatment for neuropathic pain.

Intradermal testing of iodinated contrast media: Should we test up to pure or with diluted compounds only?

BACKGROUND: Intradermal testing (IDT) with iodinated contrast media (ICMs) is an established diagnostic tool in patients with ICM hypersensitivity. Currently, it is unclear which test concentration is the more useful one, up to pure or up to 1:10 diluted ICMs. METHODS: We searched the literature database PubMed for eligible papers dealing with ICM allergy and their IDT results. We analyzed the data presented by the papers and compared the pooled groups tested with diluted and undiluted ICMs. RESULTS: We identified 29 eligible original papers, and extracted data of 1137 patients that formed the study population. Although in the cohort tested with diluted ICMs the number of tested ICMs was greater, the percentage of positive tests was significantly less (9.0% vs. 24.7%; P < 0.0001; OR 0.30 [0.26-0.34]). The frequency of positive tested culprit ICMs was also lesser in the group tested with diluted ICMs (31.0% vs. 72.5%; P < 0.0001; OR 0.17 [0.12-0.23]). The number of drug provocation tests (DPTs) was greater in patients with diluted IDTs (374 vs. 89; P < 0.0001; OR 2.54 [1.93-3.36]). We detected an increased sensitivity in patients with undiluted tests (0.774 vs. 0.282) and a nearly identical specificity in both groups (1 vs. 0.983). CONCLUSIONS: For the first time, we show that IDT up to pure ICM concentrations is superior to using diluted ICMs only. Possibly, we can reduce the number of DPTs when performing IDTs with pure ICMs. In the undiluted group, there were no hints for skin irritations or unspecific test reactions.

Direct oral challenge for immediate and non-immediate beta-lactam allergy in children: A real-world multicenter study.

BACKGROUND: Allergy to beta-lactam antibiotics (BLA) is frequently suspected in children, but a drug provocation test (DPT) rules it out in over 90% of cases. Direct oral DPT (DODPT), without skin or other previous tests, is increasingly been used to delabel non-immediate BLA reactions. This real-world study aimed to assess the safety and effectiveness of DODPT in children with immediate and non-immediate reactions to BLAs. METHODS: Ambispective registry study in children (<15 years), attended between 2016 and 2023 for suspected BLA allergy in 15 hospitals in Spain that routinely perform DODPT. RESULTS: The study included 2133 patients with generally mild reactions (anaphylaxis 0.7%). Drug provocation test with the implicated BLA was performed in 2014 patients (94.4%): 1854 underwent DODPT (86.9%, including 172 patients with immediate reactions). One hundred forty-five (7.2%) had symptoms associated with DPT, although only four reactions were severe: two episodes of anaphylaxis and two of drug-induced enterocolitis syndrome, which resolved rapidly with treatment. Of the 141 patients with mild reactions in the first DPT, a second DPT was considered in 87 and performed in 57, with 52 tolerating it without symptoms. Finally, BLA allergy was ruled out in 90.9% of the sample, confirmed in 3.4%, and remained unverified, usually due to loss to follow-up, in 5.8%. CONCLUSIONS: Direct oral DPT is a safe, effective procedure even in immediate mild reactions to BLA. Many reactions observed in DPT are doubtful and require confirmation. Severe reactions are exceptional and amenable to treatment. Direct oral DPT can be considered for BLA allergy delabeling in pediatric primary care.

Safety of direct oral provocation test to delabel reported mild beta-lactam allergy in infants.

BACKGROUND: Around 10% of people report a drug allergy and avoid some medications because of fear of allergic reactions. However, only after a proper diagnostic workup can some of these reactions be confirmed as allergic or nonallergic hypersensitivities. Beta-lactams (BLs) are the most common medication suspected of being involved in drug hypersensivity reactions (DHRs) in children. Recently, direct oral provocation tests (DPT) with BLs gained popularity within pediatric populations as a tool for delabeling children with suspected BL allergies. This study aimed to evaluate the safety of direct provocation tests in infants with mild cutaneous non-immediate reactions to BLs. METHODS: The authors retrospectively analyzed the data of 151 infants between 2015 and 2022, referred for evaluating a suspected allergy to BLs that occurred before age 24 months. RESULTS: The mean age of the children, including 55% male kids, at the suspected reaction was 15.9 months and the mean age at the time of the DPT was 39.6 months. In most cases, antibiotics were prescribed to treat common upper respiratory infections, such as acute otitis (54.3%) and acute tonsillitis (27.2%). Amoxicillin was considered the culprit drug in 62.9% of the cases, and the combination of amoxicillin-clavulanic acid in the case of 33.8% of children. The most frequent associated cutaneous clinical manifestations were maculopapular exanthema in 74.8% and delayed urticaria/angioedema in 25.2%. Of the 151 infants evaluated, parents of 149 infants agreed for a direct DPT, and only three had a positive test (2%). Symptoms resulting from the DPT were mild and easily treatable. CONCLUSIONS: A direct DPT without prior tests is a safe and effective procedure to delabel BL allergy, even in infants. The authors wish to emphasize the importance of properly validating BL allergy suspicions by promoting appropriate diagnostic procedures in infants as, in most cases, DHRs can be excluded and there is no need for further therapeutic restrictions.

The importance of clinical history in the diagnosis of drug hypersensitivity in children.

BACKGROUND: In case of suspected hypersensitivity reactions (HRs) to drugs, a challenging area for pediatricians is detecting relevant elements in the parent-reported history, in order to reach a definite diagnosis. We analyzed the concordance between the description of the HR and the medical reports documented at the time of the event. Furthermore, we studied any correlation between clinical history variables and the prediction of true allergy. METHODS: We retrospectively collected 50 charts of children referred to our Allergy Unit, after a previous access to the Emergency Department. We compared the description of the HR at acute phase to the history told by parents. Type and timing of the HR and culprit drug were classified as "known" or "unknown." The diagnosis was confirmed or excluded at the end of the investigations. Logistic regression analysis was performed to find any significant association. RESULTS: The type of the HR was known in 74%, the timing in 28%, and the culprit drug in 98%. We showed that having had a severe HR had an increased odds of remembering the timing; being older >6 years and having had an immediate HR had an increased odds of remembering the type; time to diagnostic was lower in patients whose parents remembered the type of HR. CONCLUSION: Our paper underlines the importance of an accurate anamnesis at the time of the event. Providing the physicians with a standardized Case Report Form could be a useful tool to simplify the diagnostic work-up and minimize mistakes due to lack of memory.

Safety of direct oral provocation test to delabel reported mild beta-lactam allergy in infants

Background: Around 10% of people report a drug allergy and avoid some medications because of fear of allergic reactions. However, only after a proper diagnostic workup can some of these reactions be confirmed as allergic or nonallergic hypersensitivities. Beta-lactams (BLs) are the most common medication suspected of being involved in drug hypersensivity reactions (DHRs) in children. Recently, direct oral provocation tests (DPT) with BLs gained popularity within pediatric populations as a tool for delabeling children with suspected BL allergies. This study aimed to evaluate the safety of direct provocation tests in infants with mild cutaneous non-immediate reactions to BLs. Methods: The authors retrospectively analyzed the data of 151 infants between 2015 and 2022, referred for evaluating a suspected allergy to BLs that occurred before age 24 months. Results: The mean age of the children, including 55% male kids, at the suspected reaction was 15.9 months and the mean age at the time of the DPT was 39.6 months. In most cases, antibiotics were prescribed to treat common upper respiratory infections, such as acute otitis (54.3%) and acute tonsillitis (27.2%). Amoxicillin was considered the culprit drug in 62.9% of the cases, and the combination of amoxicillin–clavulanic acid in the case of 33.8% of children. The most frequent associated cutaneous clinical manifestations were maculopapular exanthema in 74.8% and delayed urticaria/angioedema in 25.2%. Of the 151 infants evaluated, parents of 149 infants agreed for a direct DPT, and only three had a positive test (2%). Symptoms resulting from the DPT were mild and easily treatable. Conclusions: A direct DPT without prior tests is a safe and effective procedure to delabel BL allergy, even in infants... (AU)

Is a Prolonged Drug Provocation Test Better Than a Single-Day Drug Provocation Test? A Systematic Review and Meta-Analysis.

BACKGROUND: There is currently no standardized duration of drug provocation test (DPT) for confirming/delabeling beta-lactam hypersensitivity reaction (BL-HSR). OBJECTIVES: This meta-analysis and systematic review aimed to investigate the added diagnostic value of extended-day over single-day DPT for confirming/delabeling BL-HSR in adults and children. METHODS: The MEDLINE, EMBASE, Web of Science, and CINAHL online databases were searched from inception to March 15, 2023, for studies that performed extended-day DPT to confirm/delabel BL-HSR. Risk difference and risk ratio were used to compare the proportions of patients with confirmed BL-HSR by single-day or extended-day DPT. RESULTS: A total of 10,371 DPTs from 42 studies were included. Extended-day DPTs ranged from 2 to 7 days, or as long as index reactions were reported (maximum 10 days). The overall prevalence of confirmed BL-HSR was 6.96% (3.31% during the first-day DPT, and 3.65% during extended-day DPT). Approximately half of the positive reactions during extended-day DPT occurred during the second/third day. The increased detected pool prevalence of confirmed BL-HSR yielded by extended-day DPT was 0.03 (95% CI, 0.02%-0.04%; I2 = 57.69%; P < .001), and the risk ratio of positive reactions between extended-day and single-day DPT was 1.94 (95% CI, 1.62-2.33; I2 = 36.26%; P < .001). The risk difference increased per 1% increase in prevalence of BL-HSR by 0.6% (95% CI, 0.4%-0.7%; P < .001). Twenty-three severe reactions occurred during DPT, and only 2 severe reactions (0.02%) occurred during extended-day DPT. An additional 28 extended-day DPTs were needed to identify 1 mild reaction. CONCLUSIONS: The increased prevalence of confirmed BL-HSR observed during extended-day DPT could be attributed to the first-day DPT. As a result, our findings do not conclusively support the use of extended-day DPT over single-day DPT. Further studies, incorporating a washout period, are required to comprehensively compare these 2 approaches.

EAACI/ENDA position paper on drug provocation testing.

In drug hypersensitivity, drug provocation testing (DPT), also called drug challenge, is the gold standard for investigation. In recent years, risk stratification has become an important tool for adjusting the diagnostic strategy to the perceived risk, whilst still maintaining a high level of safety for the patient. Skin tests are recommended before DPT but may be omitted in low-risk patients. The task force suggests a strict definition of such low-risk patients in children and adults. Based on experience and evidence from studies of allergy to beta-lactam antibiotics, an algorithm on how to adjust DPT to the risk, and when to omit skin tests before DPT, is presented. For other antibiotics, non-steroidal anti-inflammatory drugs and other drugs, skin tests are poorly validated and DPT is frequently necessary. We recommend performing DPT with chemotherapeutics and biologicals to avoid unnecessary desensitization procedures and DPT with skin tests negative contrast media. We suggest DPT with anesthetics only in highly specialized centers. Specifics of DPT to proton pump inhibitors, anticonvulsants and corticosteroids are discussed. This position paper provides general recommendations and guidance on optimizing use of DPT, whilst balancing benefits with patient safety and optimizing the use of the limited available resources.

Approach for delabeling beta-lactam allergy in children.

A considerable number of pediatric patients treated with beta-lactam (BL) antibiotics develop delayed onset of skin rashes during the course of treatment. Although the most frequent cause of these symptoms is infectious, many cases are labeled as allergic reactions to these drugs. BL allergy labels could have a negative impact, as they imply avoidance of this group of drugs and the use of second-line antibiotics, leading to a potential increase in adverse effects and the utilization of less effective therapies. This constitutes a major public health concern and economic burden, as the use of broad-spectrum antibiotics can result in multidrug-resistant organisms and prolonged hospital stays. Therefore, it is crucial to delabel patients during childhood to avoid false labeling in adult life. Although the label of BL allergy is among the most frequent causes of allergy referral, its management remains controversial, and new diagnostic perspectives are changing the paradigm of managing BL allergies in children. Traditionally, drug provocation testing (DPT) was exclusively performed in patients who had previously obtained negative results from skin tests (STs). However, the sensitivity of STs is low, and the role of in vitro testing in the pediatric population is not well defined. Recent studies have demonstrated the safety of direct DPT without prior ST or serum tests for pediatric patients who report a low-risk reaction to BLs, which is cost-effective. However, there is still a debate on the optimal allergic workup to be performed in children with a benign immediate reaction and the management of children with severe cutaneous adverse drug reactions. In this review, we will discuss the impact of the label of BL allergy and the role of the different tools currently available to efficiently address BL allergy delabeling in children.

Diagnosis and Management of Drug-Induced Interstitial Lung Disease Associated with Amikacin Liposome Inhalation Suspension in Refractory Mycobacterium Avium Complex Pulmonary Disease: A Case Report.

Amikacin liposome inhalation suspension (ALIS) is a key drug for the treatment of refractory Mycobacterium avium complex pulmonary disease (MAC-PD). Although cases of drug-induced interstitial lung disease (DIILD) by ALIS have been reported, its diagnosis is challenging due to overlapping existing pulmonary shadows, airway bleeding, exacerbation of underlying conditions, and the potential for various concurrent infections. A 72-year-old woman started treatment with ALIS for refractory MAC-PD. Three weeks later, she had a fever, cough, and appetite loss. She was hospitalized because multiple infiltrative opacities were observed on chest X-ray and chest computed tomography. Because the opacities worsened after empiric antibiotic therapy with broad-spectrum antibiotics, we initiated corticosteroid therapy, suspecting DIILD caused by ALIS, although drug lymphocyte stimulation tests for ALIS and amikacin were negative. Three days later, we found signs of improvement and quickly tapered the corticosteroids. After obtaining informed consent, we performed a drug provocation test of ALIS. Seven days later, she exhibited fever, an increased peripheral white blood cell count, and elevated serum C-reactive protein level, all of which returned to baseline 4 days after stopping ALIS, leading to a diagnosis of DIILD caused by ALIS in this patient. DIILD caused by ALIS is rare but should be carefully diagnosed to ensure that patients with refractory MAC-PD do not miss the opportunity to receive ALIS treatment.

Ciprofloxacin-Induced Anaphylactic Reaction Followed by Negative Provocation Test in Response to Levofloxacin: A Case Report.

Fluoroquinolones are a commonly prescribed class of antibiotics due to their broad spectrum of antimicrobial activity, favorable pharmacokinetic properties, ability to switch from parenteral to oral administration, and global availability. After beta-lactams, they are the second most common antibiotic class associated with drug allergies. The mechanism of fluoroquinolone-induced hypersensitivity reactions has not yet been fully understood, so the true incidence of hypersensitivity reactions remains unknown. Cross-reactivity between fluoroquinolones has been the subject of conflicting and limited clinical research. Due to their similar chemical structure, some argue for close cross-reactivity within the group. However, recent studies have produced contradictory results. We present the case of a young patient who had an anaphylactic reaction to ciprofloxacin but was tolerant to levofloxacin, as determined via a skin prick test followed by a drug provocation test. Our findings support the notion that there is little cross-reactivity between fluoroquinolones. Consequently, exposure to another fluoroquinolone in a hospital setting may be beneficial, particularly for patients who lack adequate antibiotic alternatives. However, additional research on this subject is required.

Case of Polyethylene Glycol Allergy Confirmed with Basophil Activation Test and Oral Challenge Successfully Immunized with SARS-CoV-2 Vaccine.

Polyethylene glycols (PEG) or macrogols are polymers of ethylene oxide widely used in drugs either as active substances or, more commonly, as excipients. We report a Caucasian 32-year-old woman with referred anaphylaxis almost instantly after oral intake of a macrogol-containing laxative. Despite an anaphylactic reaction, the patient showed negative results for both the skin test and specific IgE to monomer, while the basophil activation test and oral challenge were positive. The patient was later successfully vaccinated with a polysorbate 80-containing SARS-CoV-2 vaccine following an additional work-up. As a result, the inactive form of PEG cannot be fully diagnosed, and it is considered a "hidden" allergen. Allergens like polysorbates need special consideration due to their possible cross-reactivity by their specific derivatives.

Drug provocation tests in children: All that glitters is not gold.

A proper allergy work-up, based on the gold standard drug provocation test (DPT), usually rules out suspected drug hypersensitivity in children. These tests are generally open, given their high efficiency compared with double-blind placebo-controlled DPTs. Although their negative predictive value is excellent, no studies have calculated their positive predictive value, highly dependent on the prevalence of the disease. Most studies have found a rate of <5%-10% of true beta-lactam hypersensitivity in children. Given this low prevalence (pre-test probability), a few false-positive results can significantly reduce the estimated positive predictive value. False positives may arise from the nocebo effect during the test, including nocebo by proxy, or from observer bias, which depends on professional expertise and organizational circumstances. Some studies have found a high rate of tolerance on a second DPT in children who failed the first, but these results may be affected by the interval between the two tests, of a year or more in most cases, reflecting a loss of hypersensitivity over time. Taking into account the low rate of positive DPTs, with commonly mild reactions, we suggest confirming nonsevere positive DPTs with a second provocation performed soon after the first, especially in the case of beta-lactam antibiotics, in order to improve the diagnostic accuracy, de-label more patients, and achieve a better estimation of true drug hypersensitivity prevalence. In case of mild immediate reactions, the potential benefits of a second DPT should be carefully weighed against the risk of anaphylaxis.

United States Drug Allergy Registry (USDAR) grading scale for immediate drug reactions.

BACKGROUND: There is no accepted grading system classifying the severity of immediate reactions to drugs. OBJECTIVE: The purpose of this article is to present a proposed grading system developed through the consensus of drug allergy experts from the United States Drug Allergy Registry (USDAR) Consortium. METHODS: The USDAR investigators sought to develop a consensus severity grading system for immediate drug reactions that is applicable to clinical care and research. RESULTS: The USDAR grading scale scores severity levels on a scale of 0 to 4. A grade of no reaction (NR) is used for patients who undergo challenge without any symptoms or signs, and it would confirm a negative challenge result. A grade 0 reaction is indicative of primarily subjective complaints that are commonly seen with both historical drug reactions and during drug challenges, and it would suggest a low likelihood of a true drug allergic reaction. Grades 1 to 4 meet the criteria for a positive challenge result and may be considered indicative of a drug allergy. Grade 1 reactions are suggestive of a potential immediate drug reaction with mild symptoms. Grade 2 reactions are more likely to be immediate drug reactions of moderate severity. Grade 3 reactions have features suggestive of a severe allergic reaction, whereas grade 4 reactions are life-threatening reactions such as anaphylactic shock and fatal anaphylaxis. CONCLUSION: This proposed grading schema for immediate drug reactions improves on prior schemata by being developed specifically for immediate drug reactions and being easy to implement in clinical and research practice.

Different Patterns of Response in Hypersensitivity Reactions to Arylpropionic Acid Derivatives.

BACKGROUND: Ibuprofen and other arylpropionic acid derivatives (APs) are among the most consumed nonsteroidal anti-inflammatory drugs worldwide at all age ranges; however, little is known about drug hypersensitivity reactions (DHRs) they induce. OBJECTIVE: To characterize in detail patients reporting DHRs to APs. METHODS: We prospectively evaluated patients with symptoms suggestive of AP-DHRs and analyzed their clinical characteristics, reported reactions, and diagnostic approaches. RESULTS: Six hundred sixty-two patients confirmed as hypersensitive to APs were included: 489 with cross-reactive reactions (CRs) (73.86%) and 173 with selective reactions (SRs) (26.13%). The percentage of subjects reporting reactions to ibuprofen and dexketoprofen was higher in CRs (P = .005 and P = .01, respectively), whereas naproxen and ketoprofen were more frequently involved in SRs (P = .0002 and P = .00001, respectively). The most frequent symptoms induced by ibuprofen, dexketoprofen, and naproxen were isolated angioedema and urticaria, combined or not with angioedema in both CRs and SRs. The result of nasal provocation test with lysine acetylsalicylate was positive in 156 cases (77.14% in patients showing exclusively respiratory symptoms, and in 68.18% of those with both cutaneous and respiratory involvement). To confirm diagnosis, drug provocation test with acetylsalicylic acid was required in 246 CR patients (50.3%), whereas in 28 SR patients (16.18%) drug provocation test with the culprit AP was required. CONCLUSIONS: Skin is the organ most commonly involved in AP-DHRs, with ibuprofen and dexketoprofen inducing most frequently CRs, and naproxen and ketoprofen SRs. More studies are necessary to clarify the underlying mechanism in DHRs induced by APs.

The state and consideration for skin test of ß-lactam antibiotics in pediatrics.

ß-lactam antibiotics are the most frequently used drugs and the most common drugs that cause allergic reactions in pediatrics. The occurrence of some allergic reactions can be predicted by skin testing, especially severe adverse reactions such as anaphylactic shock. Thus, penicillin and cephalosporin skin tests are widely used to predict allergic reactions before medication in pediatrics. However, false-positive results from skin tests were more often encountered in pediatrics than in adults. In fact, many children labeled as allergic to ß-lactam are not allergic to the antibiotic, leading to the use of alternative antibiotics, which are less effective and more toxic, and the increase of antibiotic resistance. There has been controversy over whether ß-lactam antibiotics should be tested for skin allergies before application in children. Based on the great controversy in the implementation of ß-lactam antibiotic skin tests, especially the controversial cephalosporin skin tests in pediatrics, the mechanism and reasons of anaphylaxis to ß-lactam antibiotics, the significance of ß-lactam antibiotic skin tests, the current state of ß-lactam antibiotic skin tests at home and abroad, and the problems of domestic and international skin tests were analyzed to determine a unified standard of ß-lactam antibiotic skin tests in pediatrics to prevent and decrease adverse drug reactions, avoid waste of drugs, and a large amount of manpower and material resource consumption.

Relevance of the diagnosis of hypersensitivity reactions to antineoplastic and biological agents: experience with drug provocation test.

Summary: Background. Evidence regarding drug provocation test (DPT) with chemotherapeutic agents is scarce. The aim of our study is to describe the experience of DPT in patients with a history of hypersensitivity reactions (HSRs) to antineoplastic and biological agents. Methods. This was an eight-year retrospective, observational, descriptive study of patients with a history of HSRs to chemotherapy who were submitted to DPT. Anamnesis, skin tests (ST) and DPT were analyzed. Patients with a negative DPT were submitted to at least one regular supervised administration (RSA). Patients with positive DPT or HSR during RSA were offered rapid drug desensitization (RDD). Results. A total of 54 patients were submitted to DPT. The most common suspected drugs were platins (n = 36), followed by taxanes (n = 11). Most initial reactions were classified as grade II (n = 39) according to Brown's grading system. ST with platinum (n = 35), taxanes (n = 10) and biological agents (n = 4) were negative, except for one intradermal test with paclitaxel, which was positive. A total of 64 DPTs were performed. Eleven percent of all DPTs were positive (platins (n = 6), doxorubicin (n = 1)). Of the 57 RSA with the culprit drugs, 2 were positive (platins). The diagnosis of hypersensitivity was confirmed by DPT/RSA in 9 patients. All patients with positive DPT/RSA presented HSRs of equal or less severity than the initial one. Conclusions. DPT followed by RSA allowed to exclude HSRs in 45 patients (55 culprit drugs). DPT before desensitization prevents non-hypersensitivity patients from undergoing RDD. In our study DPT was safe, all reactions were managed by an allergist.