Search

Currently available COVID-19 vaccines have shown a good safety profile. However, adverse effects such as local reactions have been frequently observed. Based on existing evidence, after administering the BNT162b2 (Pfizer) or AZD1222 (AstraZeneca) vaccines, more than 80% of participants developed injection site pain, while erythema and swelling were present in about 10%.

The “cytokine storm” (CS) consists of a spectrum of different immune dysregulation disorders characterized by constitutional symptoms, systemic inflammation and multiorgan dysfunction triggered by an uncontrolled immune response. Particularly in respiratory virus infections, the cytokine storm plays a primary role in the pathogenesis of respiratory disease and the clinical outcome of respiratory diseases, leading to complications such as alveolar edema and hypoxia. In this review, we wanted to analyze the different pathogenetic mechanisms involved in the various respiratory viral pandemics (COVID-19; SARS; MERS; H1N1 influenza A and Spanish flu) which have affected humans in this and last century, with particular attention to the phenomenon of the “cytokine storm” which determines the clinical severity of the respiratory disease and consequently its lethality.

Summary: Urticaria is a condition involving both skin and mucosal tissues characterized by the presence of wheals and/or angioedema. The acute form has been related to allergic reactions to drugs or foods, interaction with chemicals, or infections. We reviewed the association of urticaria with coronavirus infections. This review was carried out by the use of two search engines for published original articles, employing two key terms correlated to urticaria and viruses: "urticaria" and one term linked to each virus. The research of the relationships between SARS-CoV-2 and urticaria produced 18 papers (including a total of 114 cases). Surprisingly, the search for cases of urticaria in patients with SARS-CoV or MERS produced no results. We tried to interpret this discrepancy and attempted to analyze the possible pathogenesis of urticaria lesions in SARS-CoV-2.

SummaryWhat is known and objective Etoricoxib is a non-steroidal anti-inflammatory drug (NSAID) that inhibits the inducible cyclooxygenase (COX-2) with a good safety profile. We describe the first case of two mucosal adverse events to etoricoxib in the same patient. Case description Our patient developed stomatitis with mucosal exfoliation after etoricoxib assumption. Some months later, after a new etoricoxib intake, she presented with vaginal burning, tongue angioedema and erosions, oral exfoliation and wheals on the hands. A provocation test with diclofenac was negative. What is new and conclusion The peculiarities of our case are the rare clinical manifestation and the selective hypersensitivity to COX-2 inhibitor with tolerance to a non-selective NSAID.

Background New non-ionic contrast agents, classified into low osmolar agents and iso-osmolar agents, present different biochemical characteristics that may influence the allergic reactions they cause. The aim of our study was to evaluate how osmolarity may affect safety in the use of contrast agents. Case presentation Six patients with a positive history for reaction to contrast agent were included in this study. Only one patient prick and intradermal skin test was positive. However, in 5 cases, patients presented an immediate reaction after administration of contrast agent that was not IgE mediated. Conclusions In this study, we focused on iodixanol, an iso-osmolar contrast agent, finding good safety of this product in patients with previous hypersensitivity reactions to contrast agent.

The aim of this review is drawing the attention to the contact dermatitis, an inflammatory skin condition due to pro-inflammatory and toxic factors able to activate the skin innate immunity (irritant contact dermatitis) or caused by a T-cell- mediated hypersensitivity reaction (allergic contact dermatitis). The immune system involvement and a variety of clinical pictures are described in order to better diagnose, prevent and treat allergic contact dermatitis.

Background Specific immunotherapy is the only currently available allergen-orientated treatment able to modify the natural history of respiratory allergic diseases. Safety and clinical efficacy of this treatment are well documented, but evidence about the ability to reduce new sensitizations is still poor. Objective We report a retrospective study conducted in order to assess the prevention of new sensitizations in monosensitized subjects treated with specific immunotherapy vs. monosensitized patients treated with anti-allergic drugs. Methods 8396 monosensitized patients with respiratory symptoms were selected according to an open, retrospective design. Group A included 7182 patients submitted to specific immunotherapy (and anti-allergic drugs when needed) for 4 years and then treated with drugs for at least 3 years. Group B included 1214 patients treated only with drugs for at least 7 years. All patients underwent prick test with a standard panel of allergens and total and specific IgE determination before and after 4 years of treatment and again 3 years later. Results Groups were well balanced. Polysensitized subjects were 23.75% in Group A and 68.03% in Group B after 4 years (P

Background Nonallergic rhinitis with eosinophilia (NARES), accounting for some 15% of perennial rhinitis, is a nasal disorder whose main features are eosinophil counts in nasal smear higher than 10% and negative IgE tests. The mainstay of treatment is topical corticosteroids. Objective To evaluate the adjunctive effect of loratadine, a non-sedating antihistamine with anti-allergic activity, on nasal symptoms and eosinophil counts in nasal secretions in patients with NARES. Methods Thirty patients with NARES were divided in two groups, half receiving flunisolide two 25 μg puffs per nostril morning and night plus loratadine 10 mg u.i.d. and half the same doses of flunisolide plus placebo, according to a double-blind fashion, for 3 weeks. The effectiveness of the treatment in the two groups was evaluated by comparing symptom scores and eosinophil counts, and safety was assessed by comparing the adverse effects. Results The loratadine treated group had better results both in nasal symptoms, with a decrease in sneezing (P

Because of the widespread use of botanicals, it has become crucial for health professionals to improve their knowledge about safety problems. Several herbal medicines contain chemicals with allergenic properties responsible for contact dermatitis. Among these, one is Rosmarinus officinalis L. (rosemary), a plant used since ancient times in folk medicine; at the present time it is used worldwide as a spice and flavouring agent, as a preservative and for medicinal and cosmetic purposes. The present article aims to revise and summarise scientific literature reporting cases of contact dermatitis caused by the use of R. officinalis as a raw material or as herbal preparations. Published case reports were researched on the following databases and search engines: PUBMED, MEDLINE, EMBASE, Google Scholar, Scopus. The used keywords were: R. officinalis and rosemary each alone or combined with the words allergy, contact dermatitis, allergic contact dermatitis, sensitisation and occupational dermatitis. The published case reports show that both rosemary extracts and raw material can be responsible for allergic contact dermatitis. Two cases related to contact dermatitis caused by cross-reactivity between rosemary and thyme were also commented. The diterpene carnosol, a chemical constituent of this plant, has been imputed as a common cause for this reaction. The incidence of contact dermatitis caused by rosemary is not common, but it could be more frequent with respect to the supposed occurrence. It seems plausible that cases of contact dermatitis caused by rosemary are more frequent with respect to the supposed occurrence, because they could be misdiagnosed. For this reason, this possibility should be carefully considered in dermatitis differential diagnosis.

In radar systems and other applications circulator is an important component used for isolation or duplexing. In modern polarimetric radars it is required to transmit vertical and horizontal polarization turn by turn while receive both co and cross polarizations to serve this purpose switching (latching) circulator is inevitable device. Three port junction waveguide circulators are most widely used form of the circulators for high power conditions. This paper discusses the design a high power three port waveguide latching circulator at Ka band. The Design is done around centre frequency of 32.5 GHz using HFSS. Design is specifically made with dimension of WR-28 waveguide, so the device can be directly installed in the system using WR-28 waveguide. Isolation in excess of -45 dB is observed and Insertion Loss fraction of a dB is obtained which is quite competent with industrial standards. Latching ferrite H-plane wave guide Y-junction circulator with internal magnetic return paths has widespread applications in radars and radiometers and works as protective devices in microwave receivers.

Acute cerebellar ataxia is the most common cause of childhood ataxia, usually resulting from infections or vaccinations. Cases of acute cerebellar ataxia have been reported as a consequence of several viral and bacterial infections as well as immunizing agents, such as varicella, influenza, hepatitis B, and diphtheria-pertussis-tetanus vaccines. Although immunization with meningococcal group C conjugate vaccines has been associated with several neurological side effects, acute cerebellar ataxia has not been previously reported. The authors describe a case of a 12-year-old girl exhibiting acute cerebellar ataxia following meningococcal group C conjugate vaccination. In this patient, cerebellar symptoms started within 24 hours from the vaccination, and infective causes have been ruled out by serum and liquoral analyses. Magnetic resonance imaging findings were normal. Progressive clinical improvement was obtained after corticosteroid treatment. This case increases the small number of postvaccinal ataxias and contributes to further clarifying the complex pathogenesis of this disorder.

Polysensitization is quite frequent in allergic children and may cause difficulties for the allergist in prescribing allergen-specific immunotherapy. This study aimed at evaluating the clinical effectiveness of 1 year of sublingual immunotherapy (SLIT) in a cohort of Italian allergic children with polysensitization. This open study was performed on 51 polysensitized children (34 boys; mean age, 11.8 years; range, 5.2-17.7 years) with allergic rhinitis and/or mild to moderate asthma. All of them were treated with SLIT for 1 year. The kind and the number of prescribed allergen extracts, the type of diagnosis, the severity of symptoms, and the use of drugs were evaluated at baseline and after 1 year. The adverse events to SLIT were also evaluated. Forty-two children were treated with a single extract, four with two different extracts and three with a mix of allergens. SLIT treatment induced a significant reduction in the number of sensitizations (p = 0.018); significant improvement of allergic rhinitis classification and severity; significant reduction of ocular, nasal, and bronchial symptoms (p < 0.01 for all); and drugs use (p < 0.01 for all drugs). No systemic reactions to SLIT were observed. This open study provides evidence that polysensitization is not an obstacle for prescribing SLIT in polysensitized children. Indeed, SLIT efficacy on clinical parameters is significant after 1 year and the therapy is safe.

Monotonicity of the prunig front is proved for the Lozi map. A general expression for its Hausdorff dimension is also derived which takes into account multifractal fluctuations as well

The construction of a simple geometrical scheme for counting the number of periodic points allows to study the distribution of cycles as well as the analytic structure of the topological ζ-function of hyperbolic automorphisms of the two-dimensional torus.

The relationship between the Lyapunov spectrum of diffusively coupled one-dimensional maps and the spectrum of the discrete Schrodinger operator is stressed. As a result, an analytic expression is derived for the Lyapunov spectrum for uniformly expanding maps. It is also shown that for a coupling strength larger than a critical value, the spectrum extends to - ∞.

A 34-year-old woman referred episodes of gastrointestinal disorders and sometimes angioedema of the lips which appeared within 2 hours from the ingestion of packed food like biscuits, cereals or fruit juice. A patch test with the standard European series and with food preservatives was positive for fragrances mix. The avoidance of packed food labelled as containing flavours among the ingredients caused the disappearance of the above reported symptoms.

High oxidative stress status is known to be one of the most important factors determining cell injury in thalassemic patients and causing other serious medical complications, including a continuous proinflammatory status. The quantification of protein carbonyl groups in peripheral blood is widely used to measure the extent of oxidative modification. Thus, we measured serum concentrations of protein carbonyl groups in 30 patients affected by thalassemia major and in 15 healthy subjects. Strongly higher levels of protein carbonyl groups were measured in the blood from thalassemic patients than in that from healthy controls. Our findings evidence that thalassemic patients suffer from protein oxidative stress; the possibility of a role for carbonyl stress in the progression and severity of the disease needs further investigation.

(2003). Adverse Reactions to Pantoprazole. Scandinavian Journal of Gastroenterology: Vol. 38, No. 7, pp. 800-800.

Summary We present the case of bronchospastic reaction to clarithromycin had during a drug challenge test Personal allergic history was negative for respiratory allergies and positive for adverse drug reactions to general and regional anesthesia and to ceftriaxone After the administration of 1/4 of therapeutic dose of clarithromycin the patient showed dyspnea, cough and bronchospasm in all the lung fields The positivity of the test was confirmed by the negativity to the administration of placebo The quickness and the clinical characteristic of the adverse reaction suggest a pathogenic mechanism of immediate-type hypersensitivity On reviewing the literature we have found no reports of bronchospastic reaction to clarithromycin Macrolides are a class of antibiotics mainly used in the last years in place of b-lactams because of a broad spectrum of action and a low allergic power. In fact, there are few reports on allergic reactions to these molecules Clarithromycin is one of the latest macrolides, characterised by the presence of a 14-carbon-atom lactone ring as erythromycin, active on a wide spectrum of pathogens

Case of a 57-year-old hospital attendant with hand eczema. Patch tests were read at 2 and 3 days using the 1+ to 3+ scoring system recommended by the Contact Dermatitis Research Group.

Background: New routes of administering immunotherapy in respiratory allergy are being studied as an alternative to conventional injective immunotherapy. We carried out a study to evaluate the clinical efficacy and effects of sublingual immunotherapy in patients with Parietaria judaica-induced respiratory allergy. Methods: A double-blind, placebo-controlled design was followed. Thirty patients with P. judaica rhinoconjunctivitis, mild asthma, or both were randomly chosen for sublingual immuno-therapy (14 patients) or placebo treatment (16 patients). The patients underwent preseasonal rush induction treatment followed by coseasonal maintenance treatment during the Parietaria pollen season. Symptom and drug scores, as well as specific IgE and specific IgG4, were recorded. Results: Significantly lower symptom and drug scores were found (P=0.04), especially during the Parietaria pollination period, in the immunotherapy group. No significant difference in specific IgE and specific IgG4 was detected between the active and placebo groups; a statistically significant increase of specific IgE was detected in both groups (P=0.05). No patient undergoing active sublingual immunotherapy reported local or systemic side-effects. Conclusions: Our data suggest that sublingual immunotherapy is both clinically effective and safe in treating patients with Parietaria-induced rhinoconjunctivitis and mild asthma.

Nonallergic rhinitis with eosinophilia (NARES), accounting for some 15% of perennial rhinitis, is a nasal disorder whose main features are eosinophil counts in nasal smear higher than 10% and negative IgE tests. The mainstay of treatment is topical corticosteroids.To evaluate the adjunctive effect of loratadine, a non-sedating antihistamine with anti-allergic activity, on nasal symptoms and eosinophil counts in nasal secretions in patients with NARES.Thirty patients with NARES were divided in two groups, half receiving flunisolide two 25 microg puffs per nostril morning and night plus loratadine 10 mg u.i.d. and half the same doses of flunisolide plus placebo, according to a double-blind fashion, for 3 weeks. The effectiveness of the treatment in the two groups was evaluated by comparing symptom scores and eosinophil counts, and safety was assessed by comparing the adverse effects.The loratadine treated group had better results both in nasal symptoms, with a decrease in sneezing (P0.000001) and rhinorrhoea (P0.006), respectively, corresponding with 73.4% and 66.7% with respect to 46.6% and 26.7% in the control group, and in eosinophil counts which decreased by 20% compared with 14.3% in patients treated with placebo and flunisolide. As to safety, only nasal irritation in two patients, one in each group, was reported.Loratadine improves the effectiveness of flunisolide in treatment of NARES with no change in safety, and with no sedation.

Forty patients, monosensitized to Parietaria judaica with a clinical history of at least two years of rhinoconjunctivitis with or without asthma, were selected and randomly allocated in two groups. According to an open controlled experimental plan, twenty patients were submitted to sublingual immunotherapy (SLIT) with a solution of purified and biologically standardized extract of Parietaria judaica, following a preseasonal rush schedule. All patients, twenty belonging to the SLIT group and twenty belonging to the control group, were allowed to take authorized rescue drugs at need. At the end of the Parietaria pollen season. 15 patients for each group resulted to have complied with the criteria of the study. SLIT tolerance turned out to be excellent as no side effects were noticed in the group under treatment. No change could be detected in specific IgE and IgG4 in either group. According to the daily symptom and drug scores registered by each patient in a diary card, the SLIT group showed a statistically significant lower symptom score (p = 0.032) and lower drug plus symptom score (p = 0.037) during the peak pollen period (May-June 1994) in comparison to the group treated only with symptomatic drugs. Moreover, 13 out of 15 patients submitted to SLIT expressed a very favourable subjective opinion about the therapy and asked to continue the same treatment the following season. According to our results, the rush SLIT schedule, followed by maintenance during the pollen season, is simple, safe and effective for Parietaria pollen allergy and showed an excellent compliance.

The statistics of systems with good chaotic properties obey a formal fluctuation‐response relation which gives the average linear response of a dynamical system to an external perturbation in terms of two‐time correlation functions. Unfortunately, except for particularly simple cases, the appropriate form of correlation function is unknown because an analytic expression for the invariant density is lacking. The simplest situation is that in which the probability distribution is Gaussian. In that case, the fluctuation‐response relation is a linear relation between the response matrix and the two‐time two‐point correlation matrix. Some numerical computations have been carried out in low‐dimensional models of hydrodynamic systems. The results show that fluctuation‐response relation for Gaussian distributions is not a useful approximation. Nevertheless, these calculations show that, even for non‐Gaussian statistics, the response function and the two‐time correlations can have similar qualitative features, which may be attributed to the existence of the more general fluctuation‐response relation.

The authors propose a numerical method for extracting the spectrum of decay rates of time correlations in chaotic dynamical systems. The sum of the first p decay rates is related to the asymptotic behaviour of the time correlation of suitable exterior forms of order p. The method is applied to maps of the interval and to the Henon map.

The standard encoding procedure to describe the chaotic orbits of unimodal maps is accurately investigated. We show that the grammatical rules of the underlying language can be easily classified in a compact form by means of a universal parameter τ. Two procedures to construct finite graphs which approximate non-Markovian cases are discussed, showing also the intimate relation with the corresponding construction of approximate Markov partitions. The convergence of the partial estimates of the topological entropy is discussed, proving that the error decreases exponentially with the length of the sequences considered. The rate is shown to coincide with the topological entropyh itself. Finally, a superconvergent method to estimateh is introduced.

Background: The delay between onset of symptoms and coronary care unit admission is decisive in the outcome of patients with acute myocardial infarction. Objective: To evaluate the influence of the factors that affect the delay in acute myocardial infarction treatment. Methods: Multicenter case-control study conducted by 118 coronary care units in Italy. The median and mean times in cases and controls were compared for decision time, home-to-hospital time, and in-hospital time, and the influence of several potential risk factors on the delay was evaluated by comparison of patients admitted more than 6 hours after onset with those admitted within 6 hours after onset. Results: Among 5301 patients with acute myocardial infarction, 590 who came to a coronary care unit after 12 hours were considered cases. Controls included 600 patients treated within 2 hours, 603 between 2 and 6 hours, and 466 between 6 and 12 hours. The median decision time among cases was 50-fold higher than that of controls who presented within 2 hours. Home-to-hospital time and in-hospital time appeared to play a less important role. Among the patient-related variables, advanced age, living alone, low intensity of initial symptoms, history of diabetes, strong pain at onset of the infarction, occurrence of symptoms at night, and involvement of a general practitioner seemed to affect delay significantly. Conclusion: Interventions aimed at reducing the delay in acute myocardial infarction treatment should primarily focus on the help-seeking behavior of patients. (Arch Intern Med. 1995;155:1481-1488)

A computer-controlled X-band time domain electron paramagnetic resonance (EPR) spectrometer, with a time resolution of the order of 0.5μsec, has been constructed with many of the crucial microwave components designed and fabricated by the Microwave Engineering Group of TIFR. The spectrometer operates either in a microwave power pulsed mode for determination of spin-lattice relaxation times by the saturation recovery technique or in the kinetic mode for determination of the time dependence of EPR signal after laser excitation. It has an automatic frequency control, an automatic phase control and, most importantly, a field-frequency lock which ensures good stability of the EPR line positions enabling signal averaging for extended periods. The constructional details of the spectrometer and its performance in both the modes are described here by reporting results on certain typical systems.

The main feature of the coupled map lattice model that we investigate is the presence of periodic solutions. These can be studied analytically for homogeneous initial conditions and there is evidence that this dynamics provides some information for generic initial conditions. Due to such periodic properties this model could be helpful for the study of turbulent behaviour in reaction-diffusion processes.

Although copper sulfate can cause systemic contact dermatitis, few such cases have been recorded among copper-releasing IUD users. Reported in this paper is a case of endometritis and urticaria-angioedema syndrome in a 32-year-old user of a copper IUD. Widespread urticaria, as well as angioedema of the eyelids and the labia majora and minora, persisted for about 6 months and were not responsive to corticosteroids and H1-antagonists. Copper sulfate positivity was demonstrated in 72-hour patch test, 48-hour application of the copper spiral to forearm, and in vitro lymphocyte-stimulating test. Histologic examination of the endometrial biopsy revealed vulvovaginitis with hyperplasia of the cervical canal and T-cell and eosinophilic granulocyte infiltration. Removal of the IUD caused complete symptom remission. In experimental animals with a radioactively labeled copper IUD, small amounts of copper sulfate are absorbed through the mucus membrane and carried to the cutis through the blood or lymph. In the cutis, the allergen is intercepted from antigen-presenting cells and recognized by T cells that migrate to the lymph nodes with blastic transformation, proliferation of cytotoxic lymphocytes, and cytokine production.

The tapeworm Taenia (T.) solium can be responsible for two different conditions: taeniasis and cysticercosis. Helminth infections in human host cause an immune response associated with elevated levels of IgE, tissue eosinophilia and mastocytosis, and with the presence of CD4+ T cells that preferentially produce IL-4, IL-5, and IL-13. Individuals exposed to helminth infections may have allergic inflammatory responses to parasites and parasite antigens. PubMed search of human cases of allergic reactions occurring during T. solium infestation was performed combining the terms (allergy, urticaria, angioedema, asthma, anaphylaxis) with T. solium. A study was considered eligible for inclusion in the review if it reported data on patients with T. solium infestation who had signs or symptoms of allergy. In literature we found six articles reporting the association between an allergic reaction and T. solium infestation: two cases of urticaria, two cases of relapsing angioedema, one case of asthma and two cases of anaphylaxis. Despite the large diffusion of T. solium infestation, we found only a few cases of concomitant allergic reaction and the presence of Taenia in the host. The association between T. solium infestation and allergic manifestations has never been clearly demonstrated, and in absence of a well-documented causality the hypotheses are merely speculative. Therefore, the association between Taenia infection and allergy needs to be thoroughly studied to better clarify if this association may really exist and which is the pathogenetic mechanism supported.

The natural history of allergic rhinitis (AR) is commonly characterized by worsening of symptom severity, frequent comorbidity with asthma, and polysensitization to aeroallergens. The polysensitization phenomenon starts in early childhood. AR classification has been recently revised, and some studies investigated the new types: intermittent (IAR) and persistent (PER) AR. However, no study has been carried out on children regarding this issue. This preliminary study was performed on a large cohort of children with allergic rhinitis to evaluate the type and severity of rhinitis and its possible association with asthma, including severity grade. One hundred and thirty-nine children (86 males, 53 females, mean age 11.8 years, range 3.5–17.7 years) with allergic rhinitis were prospectively and consecutively evaluated. Seventy-one children had rhinitis alone and 68 had rhinitis associated with asthma. Forty children had IAR, 30 of whom with moderate-severe grade. Ninety-nine children had PER, 65 of whom had moderate-severe grade. The severity of AR was not associated with asthma presence (Fisher χ2 = 0.5765; Prob.=0.9018). Regarding asthma severity, 30 children had the intermittent form, whereas 38 had the persistent form: 15 mild, 22 moderate, and 1 severe. This study provides the first evidence concerning the ARIA classification in children, partially confirming findings obtained in adulthood.

School and Division of Allergy and ClinicalImmunology, University of Messina, Messina, ItalyKey words: nickel; endogenous dermatitis; IL-12;IL-10.Dr Luisa RicciardiScuola di Specializzazione in Allergologia eImmunologia Clinica PoliclinicoPadiglione H98100 MessinaItalyTel: +39 090 2212080Fax: +39 090 694773

Topological invariants of the Henon map are investigated by means of the pruning front. First, a long sequence of primary homoclinic tangencies is computed, confirming the monotonicity of the front. An algorithm to extract forbidden sequences is then introduced and discussed. Forbidden sequences of increasing lengths are used to construct a hierarchy of regular grammars, represented by directed graphs, which approximate the exact grammar arbitrarily well. The topological entropy is estimated as the largest eigenvalue of their adjacency matrix. It exhibits an exponential convergence towards the asymptotic value with an exponent in agreement with a previous conjecture based on the growth rate of the number of forbidden words.

In subjects with hypersensitivity reactions to non-steroidal anti-inflammatory drugs (NSAIDs), the choice of suitable alternative drugs with the lowest risk of reaction is imperative for therapeutic management. A safe method to exclude drug hypersensitivity is to perform a challenge test for an alternative drug. The present study was conducted to: obtain more information about the safety of NSAIDs; assess the risk of reaction following the administration of a selective or nonselective cyclooxygenase 2 (COX-2) inhibitor in patients with a history of adverse reactions to NSAIDs; investigate if age and/or gender play a role in the susceptibility to develop adverse reactions to NSAIDs.This retrospective study includes 524 patients with a history of hypersensitivity to NSAIDs admitted to undergo challenge test to an alternative anti-inflammatory drug. Statistical significance was achieved when odds ratio (OR) and risk ratio (RR) values were1.8.39% of patients with hypersensitivity reactions to NSAIDs showed a positive challenge test for the alternative drug. Challenge tests for nonselective COX-2 inhibitors were positive in 16.2% of patients with previous reaction to a same drug class and in 12.9% of patients with a history of reaction to selective COX-2 inhibitors. No positive challenge test to a non-selective COX-2 inhibitor was found in patients with a history of hypersensitivity to nimesulide (CAS 51803-78-2). Challenge tests for selective COX-2 inhibitors were positive in 4.6% of patients with a previous reaction to nonselective COX-2 inhibitors and in 7.2% of patients with a history of reaction to selective COX-2 inhibitors. The RR of a positive challenge test to a non-selective COX-2 inhibitor was significant in patients who had a history of reaction to an analogous compound (P 0.21, OR 1.31, RR 1.26).In this study, selective COX-2 inhibitors represented the class of NSAIDs less frequently reported as responsible of adverse reaction. These data underline that there is a higher risk to find a positive challenge test to a non-selective COX-2 inhibitor than to a selective one in patients with previous adverse reactions to a non-selective COX-2 inhibitor. Moreover, the data evidence that females could have a higher risk compared to males to develop an adverse reaction to selective COX-2 inhibitors. In conclusion, it appears necessary to pay attention to the kind of NSAIDs reported as the cause of hypersensitivity in anamnesis, because it must be considered a successful guide in choosing the alternative drug to administer to the patient during the challenge test.