Frequency of sensitization to common allergens: comparison between Europe and the USA

Prevalence and Determinants of Sensitisation to Neomycin in North-Eastern Italy, 1997-2021

BACKGROUND

Allergic contact dermatitis (ACD) induced by topical application of neomycin is frequently reported.

OBJECTIVES

This multi-center study investigated prevalence and determinants of neomycin sensitisations in 30 629 outpatients from North-eastern Italy during 1997-2021.

PATIENTS AND METHODS

European baseline and extended Triveneto series were applied on the upper back of patients patch testing for suspected ACD and removed after 48 h.

RESULTS

Prevalence of neomycin sensitisation was 2.29% (=701/30 629), significantly decreasing over time, especially after 2003. Neomycin sensitisation increased with age, especially in female patients older than 60 with leg dermatitis. The majority of patients sensitised to neomycin (74.5%) tested positive also against other haptens, particularly ingredients included in creams and emollients, as lanolin or benzocaine or preservatives as thimerosal or parabens.

CONCLUSIONS

The decreasing prevalence of neomycin sensitisation over time likely reflected reduced accessibility and circulation of neomycin in Italy, due to containment of prescriptions and over-the-counter accessibility. Older individuals are typically more likely to be treated by topical medications and antibiotics as neomycin for various conditions, including stasis dermatitis. Since ACD caused by topical medications is relatively easy to miss, comprehensive drug history and patch testing are essential for any patient with suspected sensitisation caused by neomycin.

Immediate and Delayed Hypersensitivity Reactions to Antibiotics: Aminoglycosides, Clindamycin, Linezolid, and Metronidazole

Hypersensitivity reactions including IgE-mediated and delayed cell-mediated reactions to aminoglycosides, clindamycin, linezolid, and metronidazole are rare. For aminoglycosides, allergic contact dermatitis is the most frequent reaction for which patch testing can be a useful step in evaluation. For clindamycin, delayed maculopapular exanthems are the most common reactions. There are case reports of clindamycin associated with drug rash with eosinophilia and systemic symptoms (DRESS), acute generalized exanthematous pustulosis (AGEP), acute febrile neutrophilic dermatosis, and symmetrical drug-related intertriginous and flexural exanthema (SDRIFE). For linezolid, cases of hypersensitivity were exceedingly rare and included urticaria, angioedema, anaphylaxis, delayed rashes, and DRESS. For metronidazole, only rare cases were found across a broad spectrum of reactions including allergic contact dermatitis, fixed drug eruption, angioedema, anaphylaxis, serum sickness-like reaction, SJS/TEN, AGEP, SDRIFE, and a possible case of DRESS. IgE-mediated reactions and anaphylaxis to these types of antibiotics are uncommon, and reports of skin testing concentrations and desensitization protocols are largely limited to case reports and series. Non-irritating skin testing concentrations have been reported for gentamycin, tobramycin, and clindamycin. Published desensitization protocols for intravenous and inhaled tobramycin, oral clindamycin, intravenous linezolid, and oral and intravenous metronidazole have also been reported and are reviewed.

Contact Allergy in Canada Versus United States: Analysis of the North American Contact Dermatitis Group Data 2005-2016

Differences in consumer product availability, distribution, and use may lead to national differences in contact sensitization frequencies.

OBJECTIVE

The aim of the study was to describe the differences in contact allergy between the United States (US) and Canada.

METHODS

This is a retrospective cross-sectional analysis of the North American Contact Dermatitis Group data from 2005 to 2016. Frequencies of demographics, clinical characteristics, positive reactions, trends, and occupations were calculated.

RESULTS

A total of 28,640 patients underwent patch testing. At least 1 positive patch test was observed in 18,599 patients (US, 11,641 [66.5%]; Canada, 6958 [62.5%]). When comparing the 2 groups, US positive reactions were more likely to occur in male patients (odds ratio [OR] = 1.40, 95% confidence interval [CI] = 1.31-1.49), older than 40 years (OR = 1.30, 95% CI = 1.22-1.38), Black (OR = 2.67, 95% CI = 2.24-3.19) or Hispanic race (OR = 3.53, 95% CI = 2.61-4.78), and/or patients with scattered generalized dermatitis (OR = 1.96, 95% CI = 1.80-2.13). They were less likely to occur in patients with eczema (OR = 0.61, 95% CI = 0.57-0.65) and Asian race (OR = 0.50, 95% CI = 0.44-0.56). Nickel (US, 16.0%; Canada, 22.4%) and methylisothiazolinone (US, 13.4%; Canada, 11.0%) were the top allergens. The third most frequent was neomycin (US, 11.7%) and fragrance mix I (Canada, 10.2%).

CONCLUSIONS

National differences in allergen prevalence and trends exist in North America.

Decreasing Rates of Neomycin Sensitization in Western Canada

Background:

Neomycin contact sensitization rates in North America range from 7% to 13%, whereas in Europe they average approximately 1.9%.

Objectives:

Given that topical neomycin products are no longer readily available in Canada, the aim of this study was to examine what influence this may have had on neomycin sensitization rates in the 3 western provinces.

Methods:

On the basis of an observation originally communicated by L. M. Parsons and C. Zhang of the University of Calgary, which suggested significantly reduced rates of neomycin sensitization in Calgary, Alberta, Canada, a multicenter study of patch test results from 5690 patient charts was undertaken. Data from 3 other western Canadian Universities (the University of Saskatchewan, the University of Alberta, and the University of British Colombia) were analyzed. Data were available from 2001 to 2013 for the University of Saskatchewan (except 2006), whereas the University of Alberta and the University of British Columbia had data from 2009 to 2013. Descriptive statistics, trend analysis, and risk estimates were determined using SPSS version 20.

Results:

Sensitization rates for neomycin have decreased in western Canada and are now similar to those of Europe.

Conclusions:

This trend is likely influenced by the reduced availability of over-the-counter and prescription neomycin products in Canada.

Antibiotic allergies in children and adults: from clinical symptoms to skin testing diagnosis

Hypersensitivity reactions to β-lactam and non-β-lactam antibiotics are commonly reported. They can be classified as immediate or nonimmediate according to the time interval between the last drug administration and their onset. Immediate reactions occur within 1 hour after the last drug administration and are manifested clinically by urticaria and/or angioedema, rhinitis, bronchospasm, and anaphylactic shock; they may be mediated by specific IgE-antibodies. Nonimmediate reactions occur more than 1 hour after the last drug administration. The most common manifestations 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 allergic examination is based mainly on in vivo tests selected on the basis of the clinical features and the type of reaction, immediate or nonimmediate. Immediate reactions can be assessed by immediate-reading skin tests and, in selected cases, drug provocation tests. Nonimmediate reactions can be assessed by delayed-reading skin tests, patch tests, and drug provocation tests. However, skin tests have been well validated mainly for β-lactams but less for other classes of antibiotics.

Hypersensitivity reactions to non beta-lactam antimicrobial agents, a statement of the WAO special committee on drug allergy

Antibiotics are used extensively in the treatment of various infections. Consequently, they can be considered among the most important agents involved in adverse reactions to drugs, including both allergic and non-allergic drug hypersensitivity [J Allergy Clin Immunol 113:832–836, 2004]. Most studies published to date deal mainly with reactions to the beta-lactam group, and information on hypersensitivity to each of the other antimicrobial agents is scarce. The present document has been produced by the Special Committee on Drug Allergy of the World Allergy Organization to present the most relevant information on the incidence, clinical manifestations, diagnosis, possible mechanisms, and management of hypersensitivity reactions to non beta-lactam antimicrobials for use by practitioners worldwide.

Contact dermatitis to topical medicaments: a retrospective chart review from the Ottawa Hospital Patch Test Clinic

BACKGROUND

Topical medicaments are a common cause of allergic contact dermatitis. This study will evaluate the prevalence of contact allergy to a wide array of topical medicaments at the Ottawa Patch Test Clinic.

OBJECTIVES

The objectives of this study are to report the results of positive patch testing to topical medicaments at the Ottawa Patch Test Clinic and identify common sensitizers in topical medicaments.

METHODS

Patients were tested with the standard North American Contact Dermatitis screening series of 70 allergens plus supplementary allergens when indicated. A retrospective chart review of patients positive to topical medicaments between January 1, 2000, and September 30, 2010, was undertaken.

RESULTS

The average age of patients was 49.5 years. Thirty-four percent were atopic. Common sensitizers included topical antibiotics (58%), steroids (30%), anesthetics (6%), and antifungals (6%). Patch testing showed that 61% of patients tested positive to antibiotics, 21% to topical steroids, 17% tested positive to topical anesthetics, and 1% tested positive to topical antifungals. The most common reactions were to bacitracin (44%) and neomycin (29%). The most common steroid screener was tixocortol-17-pivalate (group A) (19%), and the most common local anesthetic was lidocaine (12%).

CONCLUSIONS

Topical medicaments of all kinds are common causes of allergic contact dermatitis. Those that are more readily available, in over-the-counter preparations, are the most frequent culprits.