Natural evolution of skin-test sensitivity in patients with IgE-mediated hypersensitivity to cephalosporins.

There are studies demonstrating that skin-test sensitivity to penicillins can decrease over time and that allergic patients may lose sensitivity if the responsible compounds are avoided. With regard to subjects with IgE-mediated hypersensitivity to cephalosporins, however, such studies are lacking. We evaluated prospectively in a 5-year follow-up 72 cephalosporin-allergic patients. After the first evaluation, patients were classified into two groups according to their patterns of allergologic-test positivity: to both penicillins and cephalosporins (group A), or only to cephalosporins (group B). Skin tests and serum-specific IgE assays were repeated 1 year later and, in case of persistent positivity, 3 and 5 years after the first allergologic examination. Seven (43.7%) of the 16 subjects of group A and 38 (67.8%) of the 56 patients of group B became negative; one was lost to follow-up. Patients of group B became negative sooner and more frequently than group A subjects.

Absence of cross-reactivity to carbapenems in patients with delayed hypersensitivity to penicillins.

Studies performed on subjects with IgE-mediated hypersensitivity to penicillins have demonstrated a 1% rate of cross-reactivity between penicillins and both imipenem and meropenem, while a single study found a 5.5% rate of cross-reactivity with imipenem/cilastatin in subjects with T-cell-mediated hypersensitivity to ß-lactams, mostly penicillins. We studied 204 consecutive subjects with a well-demonstrated T-cell-mediated hypersensitivity to assess the cross-reactivity with carbapenems and the tolerability of such alternative ß-lactams. All 204 subjects underwent skin tests with imipenem/cilastatin and meropenem; 130 of them were skin-tested also with ertapenem. Subjects with negative test results were challenged with these carbapenems. All subjects displayed negative skin tests to carbapenems and tolerated challenges. These data demonstrate the absence of clinically significant T-cell-mediated cross-reactivity between penicillins and carbapenems. Negative delayed-reading skin testing with carbapenems in individuals with documented T-cell-mediated hypersensitivity to penicillins correlates well with subsequent clinical tolerance of therapeutic doses of carbapenems.

Cross-sectional survey on immunoglobulin E reactivity in 23,077 subjects using an allergenic molecule-based microarray detection system.

BACKGROUND: The availability of allergenic molecules and high-throughput microtechnologies allow the collection of a large number of IgE results at the same time in a single test. This can be carried out applying the test in the routine diagnostic work-up. OBJECTIVE: The aim of this study was to make a cross-sectional evaluation of the raw prevalence of IgE reactivity to allergenic molecules in serum samples from a cohort of Italian patients using an innovative tool. METHODS: The ISAC, a microarray system, has been used for specific IgE detection using 75 different allergenic molecules. Sera were collected from 23,077 unselected consecutive individuals complaining about any allergic disease. RESULTS: Sixteen thousand four hundred and eight of 23,077 patients had IgE to at least one of 75 allergenic molecules. The top-ranked molecules in this cohort were Cup a 1 (42.7%), Der f 2 (38.7%), and Phl p 1 (37.9%), whereas all the other allergens tested scored in a range between 36.8% and 0.04%, including the first food allergen, Pru p 3, ranked 15th (9.79%). Prevalence varied quite markedly depending on the age range considered, and showing a different behaviour in the lifetime sensitization process. Unsupervised two-way hierarchical clustering analysis generated distinctive patterns of reactivity as the result of IgE recognition of either homologous allergens belonging to different biological sources or non-homologous belonging to the same biological source. CONCLUSIONS: Allergen-based microarray is a tool for the detection of IgE-related sensitization to panels of allergens and gives a more precise and comprehensive evaluation for an IgE-based epidemiology. This insight brings data for better understanding of the sensitization process.

Allergic reactions to antibiotics, mainly betalactams: facts and controversies.

Allergic reactions to antibiotics are commonly reported. They can be classified as immediate or non-immediate according to the time interval between the last drug administration and their onset. Immediate reactions occur within the first hour and are manifested clinically by urticaria and/or angioedema, rhinitis, bronchospasm, and anaphylactic shock; they may be mediated by specific IgE-antibodies. The main non-immediate reactions (occurring more than one hour after drug administration) are maculopapular exanthems; specific T lymphocytes may be involved in this type of manifestation. The diagnostic evaluation of hypersensitivity reactions to antibiotics is usually complex. The patient's history is fundamental; the allergologic examination includes in vivo and in vitro tests selected on the basis of the clinical features. Prick and intradermal tests are sensitive in evaluating betalactam hypersensitivity. Together with delayed-reading intradermal testing, patch testing is useful in diagnosing maculopapular reactions to systemically administered aminopenicillins. Determination of serum specific IgE is the most common in vitro method for diagnosing immediate reactions, while the lymphocyte transformation test can be performed for evaluating both immediate and non-immediate ones. In selected cases, provocation tests should be performed.

IgE-binding and cross-reactivity of a new 41 kDa allergen of codfish.

BACKGROUND: A 41-kDa IgE-reactive protein (p41) was purified from raw cod extract. This protein is homologous to an aldehyde phosphate dehydrogenase (APDH). The present study aims to evaluate the IgE-binding and the cross-reactivity of this protein in 13 patients allergic to codfish. METHODS: IgE binding of sera from 13 patients allergic to codfish was tested by Sepharose RIA and by Western blot. RESULTS: Among the 13 patients, only 4 had specific IgE to APDH detected by APDH-Sepharose RIA. The two patients who had the highest level of specific IgE to human APDH also had a class 5-6 CAP-RAST IgE level to codfish, but two other patients with a class 5 had a negative APDH-Sepharose IgE-RIA. Relative content of APDH was higher in extracts of commercial nonfrozen fish, compared to pre rigor mortis, post rigor mortis and frozen commercial codfish. A high homology of codfish APDH was found with the corresponding human enzyme. A significant inhibition of APDH-Sepharose by human and, to a lesser extent, by rabbit APDH was observed. Western blot of APDH codfish extract showed two bands at 41 and 36 kDa, respectively. CONCLUSIONS: We have characterized a new allergen from codfish, which had a high level of homology in different species. The p41 relative content of extracts from nonfrozen codfish was higher than in the other samples assessed.

Prevalence of sensitization to Cupressus sempervirens: a 4-year retrospective study.

In the last few years Cupressus sempervirens has been identified as the cause of an increasing number of cases of late winter-early spring pollinosis in Mediterranean countries. We conducted a 4-year retrospective study of a large group of subjects with documented allergic respiratory disease in order to determine the prevalence, clinical significance and annual rate of sensitization to C. sempervirens pollen. Anamnestic data and skin prick tests (SPT) with common aeroallergens and C. sempervirens extract were collected from 1397 subjects (712 male and 685 female) resident in Latium, a region in central Italy, with complaints related to upper- or lower-respiratory-tract disorders or conjunctival disease. Two hundred and forty-three subjects (17.4%) showed positive results to C. sempervirens extract: 47 (19.3%) of them were monosensitized. The annual sensitization rate of SPT positivity to C. sempervirens varied from 7.2% in 1995 to 22% in 1998. All the subjects monosensitized to cypress pollen had symptoms from January through April. Our study suggests that sensitivity to C. sempervirens is responsible for respiratory symptoms in an increasing percentage of subjects. Further studies are needed to determine its frequency at the national level.

Tolerability of meloxicam in patients with histories of adverse reactions to nonsteroidal anti-inflammatory drugs.

BACKGROUND: Adverse reactions to nonsteroidal anti-inflammatory drugs (NSAIDs) are frequent, particularly among patients with chronic urticaria or asthma. The need to identify an alternative drug that is safe and reliable is a common problem in clinical practice. OBJECTIVE: To assess the tolerability of meloxicam, a new NSAID that selectively inhibits the inducible isoform of cyclooxygenase, in a group of NSAID-sensitive patients. PATIENTS AND METHODS: We studied 177 patients who had suffered adverse reactions to one or more NSAIDs. Cutaneous reactions were reported by 83.1% of the subjects (urticaria in 55, angioedema in 52, urticaria/angioedema in 39, and maculopapular rash in 1), respiratory symptoms by 3.9%, both cutaneous and respiratory symptoms by 9%, Stevens-Johnson's syndrome by 2.3%, and anaphylactoid reactions by 1.7%. All subjects underwent a single-blind, placebo-controlled oral challenge with divided therapeutic doses of meloxicam (1.9 mg + 5.6 mg 1 hour later = cumulative dose 7.5 mg). RESULTS: Positive reactions were observed in only two cases (1.1%), both manifested exclusively by cutaneous symptoms (urticaria/angioedema in one case and maculopapular rash/facial edema in the second). CONCLUSION: Meloxicam seems to be well tolerated by NSAID-sensitive subjects whose reactions are manifested by urticaria/angioedema. Additional study is needed for a more complete assessment of its tolerability in patients with aspirin-induced asthma and other severe manifestations of NSAID sensitivity.

Contact dermatoses in metal workers.

We studied 150 metal workers occupationally exposed to metals and metalworking fluids (MWFs) to determine the prevalence and nature of contact dermatitis. 150 office workers were used as non-exposed control group. Questionnaires were administered to evaluate occupational and non-occupational exposure. All subjects underwent a dermatological examination and patch-testing with standard allergen series and MWFs used in the plant. Twenty-eight metal workers (18.6%) presented minor skin disorders involving the hands (vs. only 2% of the controls), ten (6.6%) had major disorders (similar to the figure for the control group - 5.4%), and 112 (74.8%) had no lesions, as opposed to 92.6% of the control group. Positive patch tests were found in ten metal workers: eight had major skin disorders (six to nickel, cobalt and chromium, one to nickel and cobalt, one to nickel) and the remaining two were asymptomatic (one positive for nickel and chromium, one for nickel). Among the controls there were three cases of positivity, all among asymptomatic subjects. Patch tests with MWFs were negative. The prevalence of dermatoses among the metal workers was significantly higher than that of controls (p<0.01), and all cases of allergy in this group were provoked by metals themselves.

A diagnostic protocol for evaluating nonimmediate reactions to aminopenicillins.

BACKGROUND: Maculopapular and urticarial rashes are nonimmediate manifestations common during aminopenicillin (AP) treatment, and the former often represent cell-mediated hypersensitivity. OBJECTIVES: We sought to determine the significance and incidence of skin test reactions to APs in adults reporting adverse reactions during therapy with these beta-lactams and, particularly, to evaluate the potential of patch tests, delayed-reading skin tests, and challenges in the diagnosis of nonimmediate reactions. METHODS: We used skin tests with penicilloylpolylysine, minor determinant mixture, benzylpenicillin, ampicillin, and amoxicillin, as well as patch tests with the last 3 drugs. We also performed in vitro assays for specific IgE and challenges with the suspect penicillin in subjects with nonimmediate reactions. RESULTS: Among the 144 patients reporting nonimmediate manifestations (mostly maculopapular rashes), delayed hypersensitivity was diagnosed in 62 on the basis of positive patch test and/or delayed intradermal test results and responses to challenges; negative reactions to challenges allowed us to reasonably exclude the possibility of allergy in 66 subjects, and the challenge confirmed that 1 patient had linear IgA bullous dermatosis. Definitive diagnoses could not be provided for the remaining 15 subjects, who had negative allergologic test results, because they did not consent to challenges. In 40 of 49 immediate reactors, a diagnosis of IgE-mediated hypersensitivity was made. CONCLUSIONS: Both patch and intradermal tests are useful in evaluating nonimmediate reactions to APs. Positive patch test and delayed intradermal responses together indicate delayed hypersensitivity. Intradermal testing appears to be more sensitive than patch testing, but the pattern of positive delayed intradermal test responses and negative patch test responses needs further investigation because of false-positive cases.

Delayed hypersensitivity to diclofenac: a report on two cases.

BACKGROUND: Although skin reactions have been reported during use of diclofenac, a nonsteroidal anti-inflammatory drug, immunopathogenic mechanisms have been demonstrated in only a few cases. METHODS: We administered skin and patch tests to two subjects who had developed maculopapular rashes respectively 48 and 72 hours after initiation of treatment with diclofenac. RESULTS: In both cases, prick and intradermal tests with the drug were negative at 20 minutes, but 24 hours later an erythematous infiltrate had appeared at the intradermal test site. Patch tests with diclofenac were also positive at 48 and 72 hours. CONCLUSIONS: The features of both these cases are suggestive of delayed hypersensitivity to diclofenac. Delayed-reading intradermal and patch tests may be a simple and effective means of diagnosing reactions of this type.

Long-term tolerability of nimesulide and acetaminophen in nonsteroidal antiinflammatory drug-intolerant patients.

BACKGROUND: Oral challenges are used to identify alternative nonsteroidal antiinflammatory drugs (NSAIDs) for patients who react adversely to drugs of this class, but challenge conditions often differ from those in which the drug will actually be used. OBJECTIVE: To determine whether the results of oral challenges with nimesulide or acetaminophen, using cumulative administration of a single therapeutic dose while the patient is in good health, can predict the response to multiple doses of the drug during future illness. METHODS: Follow-up interviews were conducted with 248 NSAID-intolerant subjects who had tolerated oral challenges with nimesulide and/or acetaminophen 1 to 3 years earlier. We analyzed the adverse reaction rate in light of the febrile/non-febrile nature of the condition treated and the number of doses consumed. RESULTS: Nimesulide was tolerated by 115/122 (94.2%) of the patients who had tried it; acetaminophen by 71/75 (94.6%). A total of 8/159 (5%) patients had experienced reactions (seven urticarial and one asthmatic) to one or both drugs. Intolerance was unrelated to the nature of the condition treated or the number of doses administered, but all four patients who failed to tolerate acetaminophen and 3/7 of those who reacted to nimesulide had histories of chronic urticaria. CONCLUSIONS: Oral challenges can reliably predict long-term NSAID tolerability in patients with previous adverse reactions to other drugs of this class, except for patients with chronic urticaria.

Aminopenicillin allergy.

Eight two children with histories of maculopapular or urticarial rashes during aminopenicillin treatment underwent skin tests, patch tests, radioallergosorbent assays and, in some cases, oral challenges. Hypersensitivity was diagnosed in eight (9.8%): immediate in four with urticarial reactions and delayed (that is cell mediated) in four with maculopapular rashes. In 49 children (38 with maculopapular eruptions, 11 with urticarial/angiooedematous reactions), negative allergologic findings were confirmed using oral challenges with the suspected drug. Maculopapular rashes may reflect delayed hypersensitivity to aminopenicillins, which can be diagnosed on the basis of late intradermal reactions and/or patch test positivity. The allergen panel must include the suspected aminopenicillin itself, as many cases are side chain specific. Most patients with urticarial reactions (more typical of immediate hypersensitivity) will also react to penicilloyl polylysine and minor determinant mixture. The time elapsed between the reaction and testing must be considered if negative results emerge, because IgE mediated sensitivity (unlike cell mediated forms) declines in the absence of antigen exposure.

Allergic respiratory diseases and environmental pollution: experience in the printing/paper-manufacturing industry.

Several studies have shown a correlation between airborne pollutants and respiratory disorders. To determine whether professional exposure to industrial pollution might represent a risk factor for allergic respiratory diseases, we administered allergologic tests to 275 workers employed in a paper-making/printing factory and to a control population composed of 160 office workers from the same urban area. All subjects were evaluated on the basis of personal and family histories, the results of prick tests with common airborne allergens, specific serum IgE levels, pulmonary function test, and standard chest radiography. The percentage of subjects with allergies in the factory-worker group (67/275; 24.4%) was significantly higher than that observed among the office workers (20/160; 12.5%) (chi-square test: 8.17; P < 0.01). Of the 67 factory workers with allergies, 94% had histories of daily exposure to aliphatic hydrocarbons. The results of this study indicate that exposure to the latter type of industrial pollutants is associated with a significantly higher prevalence of allergic respiratory diseases.

Accelerated cell-mediated broncho-obstructive reaction to inhaled stepronin: a case report.

We describe the case of a 20-year-old man who developed an obstructive bronchial reaction accompanied by a maculopapular facial rash 8 h after an aerosol treatment with the mucolytic drug stepronin. The results of intradermal and patch testing with stepronin, together with those of bronchial challenge and histologic findings in patch-tested skin, indicate that the patient's reaction involved an accelerated cell-mediated mechanism of hypersensitivity. Bronchial challenges with methacholine demonstrated a transient increase in nonspecific bronchial hyperreactivity.