Ibuprofen and Other Arylpropionics: The Relevance in Immediate Hypersensitivity Drug Reactions.

BACKGROUND: Ibuprofen, a non-steroidal anti-inflammatory drug (NSAID), is the most frequent medication to be involved in hypersensitivity drug reactions (HDRs). Other analgesic/anti-inflammatory drugs in the arylpropionic group are also relevant, albeit to a lesser extent. Ibuprofen is widely consumed by people of all ages, both on medical prescription and over the counter; moreover, it is an organic contaminant of surface waters and foods. While numerous drugs cause HDR, ibuprofen's underlying mechanisms are more intricate and involve both specific immunological and non-immunological mediated reactions. SUMMARY: we concentrate on immediate responses, including urticaria with or without angioedema, anaphylaxis, and angioedema, classifying reactions according to whether they are caused by single or multiple NSAIDs and based on the mechanisms at play. Both groups may experience anaphylaxis, defined as an immediate, severe systemic reaction involving at least two organs, though the frequency and severity can vary. Following this classification, more clinical manifestations can be identified. Diagnosis is partly based on a detailed clinical history, including information about ibuprofen and/or other arylpropionic derivatives involved, the interval between drug intake and symptoms onset, clinical manifestations, number of episodes, and the patient's tolerance or response to other medications - mainly non-chemically related NSAID - both before and after reactions to ibuprofen and/or other arylpropionic drugs. A drug provocation test is frequently necessary to make a diagnosis. KEY MESSAGE: Because ibuprofen is the most widely prescribed NSAID, it is reasonable to assume its role as the leading cause of HDR will only become more important.

Relative telomere length impact on mortality of COVID-19: Sex differences.

Increasing age is associated with severity and higher mortality of COVID-19. Telomere shortening is associated with higher risk of infections and may be used to identify those patients who are more likely to die. We evaluated the association between relative telomere length (RTL) and COVID-19 mortality. RTL was measured in patients hospitalized because of COVID-19. We used Kaplan-Meier method to analyze survival probabilities, and Cox regression to investigate the association between RTL and mortality (30 and 90 days). Six hundred and eight patients were included in the analysis (mean age =72.5 years, 41.1% women, and 53.8% Caucasic). During the study period, 75 people died from COVID-19 and 533 survived. Lower RTL was associated with a higher risk of death in women either at 30 (adjusted hazard ratio [HR] (aHR) = 3.33; 95% confidence interval [CI] = 1.05-10.00; p = 0.040) and at 90 days (aHR = 3.57; 95%CI = 1.23-11.11; p = 0.019). Lower RTL was associated with a higher risk of dying of COVID-19 in women. This finding suggests that RTL has an essential role in the prognosis of this subset of the population.

Allergies and COVID-19 vaccines: An ENDA/EAACI Position paper.

BACKGROUND: Anaphylaxis, which is rare, has been reported after COVID-19 vaccination, but its management is not standardized. METHOD: Members of the European Network for Drug Allergy and the European Academy of Allergy and Clinical Immunology interested in drug allergy participated in an online questionnaire on pre-vaccination screening and management of allergic reactions to COVID-19 vaccines, and literature was analysed. RESULTS: No death due to anaphylaxis to COVID-19 vaccines has been confirmed in scientific literature. Potential allergens, polyethylene glycol (PEG), polysorbate and tromethamine are excipients. The authors propose allergy evaluation of persons with the following histories: 1-anaphylaxis to injectable drug or vaccine containing PEG or derivatives; 2-anaphylaxis to oral/topical PEG containing products; 3-recurrent anaphylaxis of unknown cause; 4-suspected or confirmed allergy to any mRNA vaccine; and 5-confirmed allergy to PEG or derivatives. We recommend a prick-to-prick skin test with the left-over solution in the suspected vaccine vial to avoid waste. Prick test panel should include PEG 4000 or 3500, PEG 2000 and polysorbate 80. The value of in vitro test is arguable. CONCLUSIONS: These recommendations will lead to a better knowledge of the management and mechanisms involved in anaphylaxis to COVID-19 vaccines and enable more people with history of allergy to be vaccinated.

Validation of a commercial allergen microarray platform for specific immunoglobulin E detection of respiratory and plant food allergens.

BACKGROUND: As the use of multiplex-specific immunoglobulin E (sIgE) detection methods becomes increasingly widespread, proper comparative validation assessments of emerging new platforms are vital. OBJECTIVE: To evaluate the clinical and technical performance of a newly introduced microarray platform, Allergy Explorer (ALEX) (MacroArray Diagnostics), in the diagnosis of pollen (cypress, grass, olive), dust mite (Dermatophagoides pteronyssinus), mold (Alternaria alternata), fruit (apple, peach), and nut (walnut, hazelnut and peanut) allergies and to compare it with those of the ImmunoCAP Immuno Solid-phase Allergen Chip (ISAC) 112 microarray and the ImmunoCAP singleplex method (ThermoFisher Scientific). METHODS: We enrolled 153 patients with allergy and 16 controls without atopy. The sIgE assays were conducted using ISAC112, ALEX version 2 (ALEX2), and ImmunoCAP for whole extracts and major components. Technical validation of ALEX2 was performed by measuring repeatability and interassay, interbatch, and interlaboratory reproducibility. RESULTS: When measured globally (detection by 1 or more allergen components), ALEX2 had adequate sensitivity and specificity for most of the allergens studied, comparable in general with that of ISAC112 (except for olive pollen and walnut) and similar to that of ImmunoCAP whole extract measurements. Component-by-component analysis revealed comparable results for all techniques, except for Ole e 1 and Jug r 3, in both ISAC112 and ImmunoCAP comparisons, and Alt a 1, when compared with ISAC112. Continuous sIgE levels correlate with sIgE by ImmunoCAP. Good reproducibility and repeatability were observed for ALEX2. CONCLUSION: ALEX2 has sound technical performance and adequate diagnostic capacity, comparable in general with that of ISAC112 and ImmunoCAP.

Beta-lactam-induced immediate hypersensitivity reactions: A genome-wide association study of a deeply phenotyped cohort.

BACKGROUND: ß-lactam antibiotics are associated with a variety of immune-mediated or hypersensitivity reactions, including immediate (type I) reactions mediated by antigen-specific IgE. OBJECTIVE: We sought to identify genetic predisposing factors for immediate reactions to ß-lactam antibiotics. METHODS: Patients with a clinical history of immediate hypersensitivity reactions to either penicillins or cephalosporins, which were immunologically confirmed, were recruited from allergy clinics. A genome-wide association study was conducted on 662 patients (the discovery cohort) with a diagnosis of immediate hypersensitivity and the main finding was replicated in a cohort of 98 Spanish cases, recruited using the same diagnostic criteria as the discovery cohort. RESULTS: Genome-wide association study identified rs71542416 within the Class II HLA region as the top hit (P = 2 × 10-14); this was in linkage disequilibrium with HLA-DRB1∗10:01 (odds ratio, 2.93; P = 5.4 × 10-7) and HLA-DQA1∗01:05 (odds ratio, 2.93, P = 5.4 × 10-7). Haplotype analysis identified that HLA-DRB1∗10:01 was a risk factor even without the HLA-DQA1∗01:05 allele. The association with HLA-DRB1∗10:01 was replicated in another cohort, with the meta-analysis of the discovery and replication cohorts showing that HLA-DRB1∗10:01 increased the risk of immediate hypersensitivity at a genome-wide level (odds ratio, 2.96; P = 4.1 × 10-9). No association with HLA-DRB1∗10:01 was identified in 268 patients with delayed hypersensitivity reactions to ß-lactams. CONCLUSIONS: HLA-DRB1∗10:01 predisposed to immediate hypersensitivity reactions to penicillins. Further work to identify other predisposing HLA and non-HLA loci is required.

Comparison of real-time and droplet digital PCR to detect and quantify SARS-CoV-2 RNA in plasma.

BACKGROUND: The presence of SARS-CoV-2 RNA in plasma has been linked to disease severity and mortality. We compared RT-qPCR to droplet digital PCR (ddPCR) to detect SARS-CoV-2 RNA in plasma from COVID-19 patients (mild, moderate, and critical disease). METHODS: The presence/concentration of SARS-CoV-2 RNA in plasma was compared in three groups of COVID-19 patients (30 outpatients, 30 ward patients and 30 ICU patients) using both RT-qPCR and ddPCR. Plasma was obtained in the first 24h following admission, and RNA was extracted using eMAG. ddPCR was performed using Bio-Rad SARS-CoV-2 detection kit, and RT-qPCR was performed using GeneFinder™ COVID-19 Plus RealAmp Kit. Statistical analysis was performed using Statistical Package for the Social Science. RESULTS: SARS-CoV-2 RNA was detected, using ddPCR and RT-qPCR, in 91% and 87% of ICU patients, 27% and 23% of ward patients and 3% and 3% of outpatients. The concordance of the results obtained by both methods was excellent (Cohen's kappa index = 0.953). RT-qPCR was able to detect 34/36 (94.4%) patients positive for viral RNA in plasma by ddPCR. Viral RNA load was higher in ICU patients compared with the other groups (P < .001), by both ddPCR and RT-qPCR. AUC analysis revealed Ct values (RT-qPCR) and viral RNA load values (ddPCR) can similarly differentiate between patients admitted to wards and to the ICU (AUC of 0.90 and 0.89, respectively). CONCLUSION: Both methods yielded similar prevalence of RNAemia between groups, with ICU patients showing the highest (>85%). RT-qPCR was as useful as ddPCR to detect and quantify SARS-CoV-2 RNAemia in plasma.

An EAACI Task Force report on allergy to beta-lactams in children: Clinical entities and diagnostic procedures.

Beta-lactam (BL) allergy suspicion is common in children and constitutes a major public health problem, with an impact on patient's health and on medical costs. However, it has been found that most of these reactions are not confirmed by a complete allergic workup. The diagnostic value of the currently available allergy tests has been investigated intensively recently by different groups throughout the world. This has led to major changes in the management of children with a suspected BL allergy. Particularly, it is now well accepted that skin tests can be skipped before the drug provocation test in children with a benign non-immediate reaction to BL. However, there is still a debate on the optimal allergic workup to perform in children with a benign immediate reaction. In addition, management of children with severe cutaneous adverse drug reactions remains difficult. In this review, based on a selection of the most relevant studies found in the literature, we will review and discuss the diagnosis of different forms of BL allergy in children.

Delayed hypersensitivity to antiepileptic drugs in children.

BACKGROUND: Antiepileptic drugs (AEDs) are widely used for the treatment of epilepsy, but they can be associated with the development of mainly delayed/non-immediate hypersensitivity reactions (HRs). Although these reactions are usually cutaneous, self-limited, and spontaneously resolve within days after drug discontinuation, sometime HR reactions to AEDs can be severe and life-threatening. AIM: This paper seeks to show examples on practical management of AED HRs in children starting from a review of what it is already known in literature. RESULTS: Risk factors include age, history of previous AEDs reactions, viral infections, concomitant medications, and genetic factors. The diagnostic workup consists of in vivo (intradermal testing and patch testing) and in vitro tests [serological investigation to exclude the role of viral infection, lymphocyte transformation test (LTT), cytokine detection in ELISpot assays, and granulysin (Grl) in flow cytometry. Treatment is based on a prompt drug discontinuation and mainly on the use of glucocorticoids. CONCLUSION: Dealing with AED HRs is challenging. The primary goal in the diagnosis and management of HRs to AEDs should be trying to accurately identify the causal trigger and simultaneously identify a safe and effective alternative anticonvulsant. There is therefore an ongoing need to improve our knowledge of HS reactions due to AED medications and in particular to improve our diagnostic capabilities.

Patterns of response and drugs involved in hypersensitivity reactions to beta-lactams in children.

BACKGROUND: Beta-lactams generate different allergenic determinants that induce selective or cross-reactive drug hypersensitivity reactions (DHRs). We aimed to identify the drugs involved, the selectivity of the response, the mechanism, and the value of the different diagnostic tests for establishing a diagnosis in children evaluated for DHRs to beta-lactams. METHODS: Prospective study evaluating children aged under 16 years reporting DHRs to beta-lactams. Reactions were classified as immediate and non-immediate reactions. The workup included sIgE, skin testing, and drug provocation tests (DPTs) for immediate reactions and patch testing and DPTs for non-immediate ones. RESULTS: Of the 510 children included, 133 were evaluated for immediate reactions and confirmed in 8.3%. Skin test/in vitro IgE contributed to diagnosing half of the cases. Selective reactions occurred with amoxicillin (63%), followed by common penicillin determinants (27%) and cephalosporins (0.9%). Among non-immediate reactions (11.4% of the 377 children evaluated), most required DPTs, 52.7% of which were positive at 6-7 days of drug challenge. Selective reactions were identified with amoxicillin (80%), penicillin G (7.5%), cephalosporins (7.5%), and clavulanic acid (5%). Urticaria and maculopapular exanthema were the most frequent entities. CONCLUSIONS: There were few confirmed cases of either type of reaction. Skin testing proved less valuable in non-immediate reactions, over half of which would also have been lost in a short DPT protocol. Selective responders to amoxicillin were more likely to have non-immediate reactions, while clavulanic acid selectivity was exclusive to the non-immediate typology. Over half the cases with DPTs required 6-7 days of treatment for DHR confirmation.

EAACI/ENDA Position Paper: Diagnosis and management of hypersensitivity reactions to non-steroidal anti-inflammatory drugs (NSAIDs) in children and adolescents.

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used in the pediatric population as antipyretics/analgesics and anti-inflammatory medications. Hypersensitivity (HS) reactions to NSAID in this age group, while similar to adults, have unique diagnostic and management issues. Although slowly accumulating, published data in this age group are still relatively rare and lacking a unifying consensus. This work is a summary of current knowledge and consensus recommendations utilizing both published data and expert opinion from the European Network of Drug Allergy (ENDA) and the Drug Hypersensitivity interest group in the European Academy of Allergy and Clinical Immunology (EAACI). This position paper summarizes diagnostic and management guidelines for children and adolescents with NSAIDs hypersensitivity.

Copy number variation in ALOX5 and PTGER1 is associated with NSAIDs-induced urticaria and/or angioedema.

OBJECTIVE: Cross-intolerance to NSAIDs is a class of drug hypersensitivity reaction, of which NSAIDs-induced urticaria and/or angioedema (NIUA) are the most frequent clinical entities. They are considered to involve dysregulation of the arachidonic acid pathway; however, this mechanism has not been confirmed for NIUA. In this work, we assessed copy number variations (CNVs) in eight of the main genes involved in the arachidonic acid pathway and their possible genetic association with NIUA. MATERIALS AND METHODS: CNVs in ALOX5, LTC4S, PTGS1, PTGS2, PTGER1, PTGER2, PTGER3, and PTGER4 were analyzed using TaqMan copy number assays. Genotyping was carried out by real-time quantitative PCR. Individual genotypes were assigned using the CopyCaller Software. Statistical analysis was carried out using GraphPad prism 5, PLINK, EPIDAT, and R version 3.1.2. RESULTS AND CONCLUSION: A total of 151 cases and 139 controls were analyzed during the discovery phase and 148 cases and 140 controls were used for replication. CNVs in open reading frames were found for ALOX5, PTGER1, PTGER3, and PTGER4. Statistically significant differences in the CNV frequency between NIUA and controls were found for ALOX5 (Pc=0.017) and PTGER1 (Pc=1.22E-04). This study represents the first analysis showing an association between CNVs in exonic regions of ALOX5 and PTGER1 and NIUA. This suggests a role of CNVs in this pathology that should be explored further.

Allergic Reactions to Metamizole: Immediate and Delayed Responses.

BACKGROUND: Pyrazolones are the most common causes of selective nonsteroidal anti-inflammatory drug (NSAID) hypersensitivity. We studied a large group of patients with immediate and delayed selective responses to metamizole. METHODS: Patients with suspicion of hypersensitivity to metamizole were evaluated. We verified acetylsalicylic acid tolerance and classified patients as immediate or delayed responders if they showed symptoms less or more than 24 h after metamizole administration. Skin tests were performed and if negative, a basophil activation test (BAT) was performed on immediate responders. If it was negative, we performed a drug provocation test (DPT) with metamizole. RESULTS: A total of 137 patients were included: 132 reacted within 24 h (single NSAID-induced urticaria/angioedema/anaphylaxis; SNIUAA) and 5 after 24 h (single NSAID-induced delayed hypersensitivity reaction; SNIDHR). Most SNIUAA patients developed anaphylaxis (60.60%); for SNIDHR, maculopapular exanthema was the most frequent entity (60%). Skin testing was positive in 62.04% of all cases and BAT in 28% of the SNIUAA patients with negative skin tests. In 5.1% of the cases, DPT with metamizole was needed to establish the diagnosis. In 22.62% of the cases, diagnosis was established by consistent and unequivocal history of repeated allergic episodes in spite of a negative skin test and BAT. CONCLUSIONS: SNIUAA to metamizole is the most frequent type of selective NSAID hypersensitivity, with anaphylaxis being the most common clinical entity. It may occur within 1 h after drug intake. SNIDHR occurs in a very low percentage of cases. The low sensitivity of diagnostic tests may be due to incomplete characterization of the chemical structures of metamizole and its metabolites.

Genetic Variants of Thymic Stromal Lymphopoietin in Nonsteroidal Anti-Inflammatory Drug-Induced Urticaria/Angioedema.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most frequent agents involved in hypersensitivity drug reactions, with NSAID-induced urticaria and/or angioedema (NIUA) being the most common entity. Mast cells are key players in NIUA and are activated by thymic stromal lymphopoietin (TSLP). This cytokine functions through recognition by its receptor, composed of IL7Rα (interleukin-7 receptor alpha) and TSLPR (TSLP receptor). These genes have been previously associated with other inflammatory diseases. METHODS: We assessed the genetic association between single nucleotide polymorphisms (SNPs) in TSLP, IL7R and TSLPR and NIUA in Spanish individuals, using genotyped and imputed data. A total of 369 unrelated NIUA patients and 580 NSAID-tolerant control subjects were included, and 6 SNPs in TSLP, 6 in IL7R and 3 in TSLPR were genotyped. Further variants were imputed using Mach and the 1,000 Genomes Project (Phase 3) data. Association testing and statistical analyses were performed with Mach2dat and R. RESULTS: A total of 139 SNPs were tested for association following quality control. Two SNPs in TSLP (rs1816678 and rs764917) showed a nominal association (p = 0.033 and 0.024, respectively) with NIUA, although these results were not statistically significant after correcting for multiple comparisons. CONCLUSIONS: Although TSLP, IL7R and TSLPR are important genes involved in the development of the inflammatory response, we found no significant genetic association with NIUA in our population for common SNPs in these genes.

HLA-DRA variants predict penicillin allergy in genome-wide fine-mapping genotyping.

BACKGROUND: Immediate reactions to ß-lactams are the most common causes of anaphylactic reactions and can be life-threatening. The few known genetic factors influencing these reactions suggest a link with atopy and inflammation. OBJECTIVE: We performed a fine-mapping genome-wide association study of the genetic predictors of ß-lactam allergy to better understand the underlying mechanisms. METHODS: We studied 387 patients with immediate allergic reactions to ß-lactams and 1124 paired control subjects from Spain. We replicated the results in 299 patients and 362 paired control subjects from Italy. RESULTS: We found significant associations with the single nucleotide polymorphisms rs4958427 of ZNF300 (c.64-471G>A, P = 9.9 × 10(-9)), rs17612 of C5 (c.4311A>C [p.Glu1437Asp], P = 7.5 × 10(-7)), rs7754768 and rs9268832 of the HLA-DRA | HLA-DRB5 interregion (P = 1.6 × 10(-6) and 4.9 × 10(-6)), and rs7192 of HLA-DRA (c.724T>G [p.Leu242Val], P = 7.4 × 10(-6)) in an allelic model, with similar results in an additive model. Single nucleotide polymorphisms of HLA-DRA and ZNF300 predicted skin test positivity to amoxicillin and other penicillins but not to cephalosporins. A haplotype block in HLA-DRA and the HLA-DRA | HLA-DRB5 interregion encompassed a motif involved in balanced expression of the α- and ß-chains of MHC class II, whereas rs7192 was predicted to influence α-chain conformation. HLA-DRA rs7192 and rs8084 were significantly associated with allergy to penicillins and amoxicillin (P = 6.0 × 10(-4) and P = 4.0 × 10(-4), respectively) but not to cephalosporins in the replication study. CONCLUSIONS: Gene variants of HLA-DRA and the HLA-DRA | HLA-DRB5 interregion were significant predictors of allergy to penicillins but not to cephalosporins. These data suggest complex gene-environment interactions in which genetic susceptibility of HLA type 2 antigen presentation plays a central role.

Genetic determinants of metamizole metabolism modify the risk of developing anaphylaxis.

Metamizole is a NSAID that has been banned in several countries because of its toxicity. It is often involved in selective hypersensitivity reactions and most hypersensitivity patients develop anaphylaxis. Metamizole is rapidly metabolized, and metabolic profiles are related to genetic factors. We analyzed whether genetic determinants of metamizole metabolism influence the risk of developing hypersensitivity in 265 patients diagnosed with hypersensitivity to metamizole and 362 healthy individuals who tolerated metamizole. Slow acetylation is associated with an increased risk of developing selective hypersensitivity to metamizole [odds ratio for slow alleles=2.17 (95% confidence interval=1.44-3.27); P=0.00016], and particularly anaphylaxis [odds ratio=4.77 (95% confidence interval=2.28-9.98); P=0.000006], with a significant gene-dose effect. The association was not identified in patients with cross-hypersensitivity. Cytochrome P450 2C9 (CYP2C9) and cytochrome P450 2C19 (CYP2C19) genotypes did not influence risk association. Our findings raise the hypothesis of genetically determined metabolic variability as a risk factor for developing anaphylaxis with metamizole.

Association study of genetic variants in PLA2G4A, PLCG1, LAT, SYK, and TNFRS11A genes in NSAIDs-induced urticaria and/or angioedema patients.

NSAIDs-induced urticaria and/or angioedema (NIUA) is the most frequent entity of hypersensitivity reactions to NSAIDs. The underlying cause is considered to be because of a nonspecific immunological mechanism in which mast cells are key players. We studied the association of nine single nucleotide polymorphisms in five genes involved in mast cell activation (SYK, LAT1, PLCG1, PLA2G4A, and TNFRSF11A) in 450 NIUA patients and 500 controls. We identified several statistically significant associations when stratifying patients by symptoms: PLA2G4A rs12746200 (urticaria vs. controls, Pc=0.005). PLCG1 rs2228246 (angioedema vs. controls; Pc=0.044), and TNFRS11A rs1805034 (urticaria+angioedema vs. controls; Pc=0.041). The frequency of haplotype PLCG1 rs753381-rs2228246 (C-G) in angioedema-NIUA patients was lower than that in controls (Pc=0.040). In addition, the haplotype frequency of TNFRS11A rs1805034-rs35211496 (C-T) was higher among urticaria-NIUA and urticaria+angioedema-NIUA patients than the controls (Pc=0.045 and 0.046). Our results shed light on the involvement of variants in genes related to non-immunological mast cell activation in NIUA.

Role of Histamine Release Test for the Evaluation of Patients with Immediate Hypersensitivity Reactions to Clavulanic Acid.

BACKGROUND: Immediate hypersensitivity reactions to clavulanic acid (CLV) seem to be on the increase. Diagnosis is mainly based on skin testing and the drug provocation test (DPT), procedures that are not risk free. The aim of this study was to evaluate whether the histamine release test (HRT) could help evaluate patients with selective hypersensitivity to CLV. METHODS: Eighteen patients with immediate selective hypersensitivity reactions to CLV (positive skin tests to CLV but negative to the major and minor determinants of benzylpenicillin and amoxicillin; negative DPT to benzylpenicillin and amoxicillin) and 21 controls with tolerance to CLV were included. Direct and passive HRT, using patient whole blood or 'IgE-stripped' donor blood sensitized by patient serum, respectively, were performed by stimulating the blood with CLV, and basophil histamine release was detected by fluorometric determination. RESULTS: The clinical symptoms were anaphylaxis (n = 6), urticaria (n = 9) and urticaria-angioedema (n = 3). The median time interval between the reaction and the study was 225 days (interquartile range, IQR: 120-387.5) and between drug intake and the development of symptoms 30 min (IQR: 6.25-30). We obtained similar data for both the direct and passive HRT, with a sensitivity and specificity of 55 and 85%, respectively, a positive predictive value of 76% and a negative predictive value of 69%. CONCLUSIONS: The sensitivity of both the direct and passive HRT for diagnosing patients with immediate allergy to CLV is less than 60%. However, the passive HRT has the advantage that it is based on the testing of serum samples that can be handled more easily than fresh blood samples.

Follow-up study in local allergic rhinitis shows a consistent entity not evolving to systemic allergic rhinitis.

BACKGROUND: Local allergic rhinitis (LAR) is a common disease that affects 25.7% of the rhinitis population and more than 47% of patients previously diagnosed with nonallergic rhinitis. Whether LAR is the first step in the natural history of allergic rhinitis (AR) with systemic atopy or a consistent entity is unknown. OBJECTIVE: The aim was to evaluate the natural history of a population with LAR of recent onset and the development of AR and asthma. METHODS: A prospective 10-year follow-up study with initial cohorts of 194 patients with LAR of recent onset and 130 healthy controls is being undertaken. A clinical-demographic questionnaire, spirometry, skin prick test, and specific IgE to aeroallergens were done yearly. Nasal allergen provocation tests with Dermatophagoides pteronyssinus, Alternaria alternata, Olea europea, and a mix of grass pollen were performed at baseline and after 5 years. RESULTS: At disease onset, most of the patients with LAR had moderate-to-severe persistent-perennial rhinitis; conjunctivitis and asthma were the main comorbidities (51.1% and 18.8%, respectively), and D pteronyssinus was the most relevant aeroallergen (51.1%). After 5 years of follow-up, a worsening of rhinitis was detected in 26.2%, with an increase in symptom persistence and severity, and new associations with conjunctivitis and asthma. Atopy was detected by skin prick test and/or serum specific-IgE in patients with LAR (6.81%) and in controls (4.5%). CONCLUSIONS: This study shows a similar rate of development of systemic atopy in LAR and controls, which suggests that LAR is an entity well differentiated from AR. To determine the natural course of LAR more precisely, this study is in progress to complete 10 years of follow-up.