Background: Fixed drug eruption (FDE) represents a drug-related cutaneous reaction.Many drugs been associated with this clinical entity, with continually evolving documentation of implicated agents and clinical presentations. A bullous form can occur although it is rare.Objectives: To assess the epidemiological and clinical characteristics of FDE. Methods: We retrospectively analysed all FDE cases who presented to the ClinicalPharmacology Department at the University Hospital, Monastir, Tunisia, for allergy workup.Results: The mean age of the 41 confirmed FDE cases was 43.8 ± 15.5 years. The time between first lesion onset and FDE diagnosis was less than 1 month for 13 patients (31.7%). Fifteen patients had bullous lesions. The upper limbs were the most common location (65.9% of cases). The patch tests were positive in 27 cases; a provocation test yielded a positive response in the four cases tested. Nonsteroidal anti-inflammatory drugs (NSAIDs) were involved in 51.2%, antibiotics in 24.4%, and other analgesics in 19.5%. The most common offending drug was mefenamic acid in 24.4% of cases. Bullous lesions were significantly associated with paracetamol intake (P = .014; odds ratio 16.7; 95% confidence interval: 1.76-158).Conclusions: NSAIDs and antibiotics were the most implicated in inducing FDE; paracetamol was associated with bullous lesions. K E Y W O R D Sepidemiology, fixed drug eruption, oral rechallenge, patch test

Patients with positive STs 9 Patients with positive STs to all NMBAs 30 Patients lost to follow-up 26 Patients without new general anaesthesia 92 Patients with a new general anaesthesia 67 Without NMBA 25 Using NMBA 148 Patients contacted Patie Fig 1. Flow chart of the study. NMBA, neuromuscular blocking agent; ST, skin test.

Drug allergy work-up in betalactam (BL) allergy is probably the most-developed drug-allergy evaluation at present. 1 During the last few years, the debate on whether 1-day or several-day (prolonged) drug provocation test (DPT) should be performed in non-immediate reactions (ie, occurring >1 hour after the last administered dose) in order to increase sensitivity has been ongoing and groups working in drug allergy diagnosis have been deploying pro and con arguments and studies in favour of either option. [2][3][4][5] The most acceptable way to validate a negative DPT is by studying its negative predictive value (NPV) in patients who are re-challenged to the negatively tested drug, in real-life therapeutic conditions. 6,7 Because therapeutic conditions imply underlying infectious disease (and therefore, a differential diagnosis responsible of cutaneous eruptions, independent of medication), performing a follow-up of tested patients including retest if necessary is advisable, under the hypothesis that not all reactions occurring upon retaking the drug are drug-related.The number needed to harm (NNH) is a measure of the harm caused by an intervention. More specifically, it is a measure of how many people need to be exposed to an intervention, (eg, DPT) in order for one person to have a particular adverse effect (eg, a DHR):the larger the value of the number needed to harm, the lower the risk of the adverse effect. In the specific case of DPT, prolonged DPT deliver courses of antibiotics in subjects that are otherwise healthy and this intervention may have additional drawbacks at a higher overall level (eg, microbial resistance and economic costs). If the NNH is high, and considering that prolonged DPT pick up merely mild reactions (as confirmed by the studies performing prolonged DPT 2-4 ), prolonged DPT might not be an effective intervention as compared to 1-day DPT. Between December 2014 and June 2016, a multicentre (NCT02844712) study was conducted in two allergy units, Hôpital Arnaud de Villeneuve (Montpellier, France) and Complesso Integrato Columbus (Rome, Italy). Patients with a complete and negative allergy work-up for a BL were contacted and asked to answer a questionnaire regarding re-administration of a negatively tested BL, as previously described. 6 Both centres perform 1-day DPT in both immediate and in mild/moderate non-immediate suspicions of BL drug hypersensitivity reactions (DHR), in a similar manner (including contraindications for DPT). Data were expressed either as numbers and percentage (with 95% CIs) or as medians (with interquartile range). Comparisons were made using chi-square tests for categorical variables. Clinical risk factors for developing a reaction upon subsequent re-challenge in real-life were searched using multivariate logistic regression. A total of 950 patients, 208 (21.9%) from Rome and 742 (78.1%) from Montpellier, answered and returned the questionnaire. The index reaction had been immediate in 152 (16%) of patients, and non-immediate (or of unknown chronology) for the rem...