Sources of sensitization, cross-reactions, and occupational sensitization to topical anaesthetics among general dermatology patients

Adverse Reactions to Illicit Drugs (Marijuana, Opioids, Cocaine) and Alcohol

Drug allergy has been a research topic within the allergy field for decades. However, many drug reactions presumed to be of allergic nature are not and originate from different mechanisms. Drug-induced reactions can affect numerous organ systems, present with various symptoms, and have more than 1 mechanism of action. In this rostrum article, we want to give an overview of the different allergic and nonallergic reactions that can be expected with the (illicit) use of cannabis, cocaine, opioids, and alcohol. In addition, this article focuses on the different methods available to diagnose allergy related to these 4 drug types and highlight the pitfalls of nonallergic reactions or allergy "mimickers" complicating the diagnosis of true drug allergy. Finally, the impact on current medical practices and future research in support of the allergist in diagnosis and treatment of these medical problems is addressed.

Analysis of Prevalence and Risk Factors of Contact Sensitization with respect to the Occupational Profiles in a Greek Patient Cohort: A Retrospective Analysis of a Greek Referral Centre and Future Perspectives

Contact dermatitis is a frequent skin disorder related to environmental and occupational etiological factors, which could potentially affect all age groups, as well as both genders. The current study is aimed at exploring the patterns of contact sensitization with respect to the population's occupational patterns in Greece. A retrospective analysis was performed in a cohort of 1978 patients from 2014 to 2016. Patients were divided into two categories; blue collars (BlC) and white collars (WhC), as well as detailed occupation was considered. Separation was performed on the basis of their profession, i.e., labor workers and handicraftsmen were sorted to the BlC group, while office employees were sorted to the WhC group. The common allergen in all occupational subgroups was nickel sulphate. The three most prevalent allergens in both BlC and WhC were nickel sulphate 5%, fragrance mix (I) 8%, and Balsam of Peru 25%. WhC males were uniquely sensitized to colophony 20% and formaldehyde 2%, and WhC females were uniquely sensitized to 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT) and neomycin sulphate 20%. Sensitization to allergens manifested occupation-specific patterns. Allergic contact dermatitis surveillance is of great importance towards the clinical and systematic understanding of the disease, especially with respect to the patient's occupational profile.

Allergic Contact Dermatitis to Pramoxine (Pramocaine)

Prescription and over-the-counter topical anesthetics are commonly used. Although allergy to amide and ester anesthetics is known, little has been reported on the nonamide, nonester pramoxine (pramocaine). This article briefly reviews allergy to topical anesthetics, provides detailed information on pramoxine, and describes characteristics of multiple patients with positive, relevant reactions to pramoxine.

Topical Brimonidine as an Effective Adjuvant to Local Anesthetics for Post Treatment Erythema and Pain Reduction

Background

There are few pharmacologic options to reduce laser-associated post treatment erythema and to extend topical anesthesia duration. To improve the tolerability of painful laser treatment, dermatologists should encourage development of a novel adjuvant agent to topical lidocaine cream.

Objective

To report the efficacy and safety of a combination of topical brimonidine and anesthetic cream as an aid for post treatment erythema and pain.

Methods

A total of 15 Korean subjects were randomized to receive a split-face application of a mixture of brimonidine and anesthetics on one side and only anesthetics on the other side of the face for anesthesia. After non-ablative fractional full-face skin resurfacing, Clinician's Erythema Assessment, erythema index, and visual analogue scale were assessed at four time points: immediately after resurfacing, 30 minutes after, 60 minutes after, and 1 day after.

Results

A combination of brimonidine and anesthetics significantly lowered post treatment erythema until 60 minutes after the laser procedure. Furthermore, patients reported significantly lower post-procedural pain from the side of their face that received the mixture of anesthetics and brimonidine than they did for the side that only received anesthetics.

Conclusion

Topical brimonidine can be used as an effective adjuvant agent to lidocaine-based topical anesthetics.

Differential diagnosis of late-type reactions to injected local anaesthetics: Inflammation at the injection site is the only indicator of allergic hypersensitivity

BACKGROUND

Anaphylaxis-like reactions developing within a few minutes are the most frequent complications of subcutaneous or submucosal injections of local anaesthetics (LAs), and topically applied LAs are potential contact allergens. In addition, injected LAs have been reported to induce delayed reactions, including local inflammation at the injection site, and various general symptoms.

OBJECTIVES

To assess the frequency and symptoms of late-type hypersensitivity occurring several hours after LA injections.

METHODS

We retrospectively evaluated clinical data and test results from all patients referred to our allergy clinic in a period of 20 years for diagnostic work-up of LA-associated late-type reactions.

RESULTS

Of 202 patients reporting symptoms with onset at least 1 hour after LA injection, 40 had cutaneous inflammation confined to the injection site, and 162 reported various systemic symptoms. LA hypersensitivity could be excluded in all patients with systemic complaints by means of skin testing and subsequent subcutaneous provocation. In 8 of the 40 patients (20%) with local inflammatory reactions, late-type allergic LA hypersensitivity was confirmed.

CONCLUSIONS

Late-type LA allergy commonly causes inflammatory skin reactions confined to the injection site. Conversely, LAs are highly unlikely to trigger delayed systemic symptoms such as urticarial or exanthematous skin eruptions.

Cocaine Allergy in Drug-Dependent Patients and Allergic People

BACKGROUND

Adverse reactions to local anesthetics (LAs), especially esters, are not uncommon, but true allergy is rarely diagnosed. To our knowledge, currently there is no reliable method of determining IgE-mediated hypersensitivity to LAs and cocaine.

OBJECTIVE

To assess the clinical value of allergy tests (prick, IgE, challenges, and arrays) in people suffering hypersensitivity reactions (asthma and anaphylaxis) during local anesthesia with cocaine derivatives and drug abusers with allergic symptoms after cocaine inhalation.

METHODS

We selected cocaine-dependent patients and allergic patients who suffered severe reactions during local anesthesia from a database of 23,873 patients. The diagnostic yield (sensitivity, specificity, and predictive value) of allergy tests using cocaine and coca leaf extracts in determining cocaine allergy was assessed, taking a positive challenge as the criterion standard.

RESULTS

After prick tests, specific IgE, and challenge with cocaine extract, 41 of 211 patients (19.4%) were diagnosed as sensitized to cocaine. Prick tests and IgE to coca leaves (coca tea) had a good sensitivity (95.1% and 92.7%, respectively) and specificity (92.3 and 98.8%, respectively) for the diagnosis of cocaine allergy and LA-derived allergy.

CONCLUSIONS

Cocaine may be an important allergen. Drug abusers and patients sensitized to local anesthesia and tobacco are at risk. Both prick tests and specific IgE against coca leaf extract detected sensitization to cocaine. The highest levels were related to severe clinical profiles.

Lidocaine Allergy: Do Positive Patch Results Restrict Future Use?

BACKGROUND

Adverse reactions from lidocaine are commonly reported. When allergy is suspected, patients may be referred for specific skin testing to confirm the association of their clinical findings.

OBJECTIVE

We aimed to investigate 13 cases of suspected lidocaine allergy to analyze if positive patch results restricted future use as an injectable local anesthetic.

METHODS

A prospective study was conducted from March 2013 to September 2014 at 2 academic hospital-based patch test clinics in Toronto. Patients were tested to the North American Contact Dermatitis Group standard series (Smart Practice, Phoenix, AZ) and, if suspicion for lidocaine allergy was high, a local anesthetic series (Chemotechnique Diagnostics, Malmö, Sweden) was added. Intradermal skin testing to local anesthetics below irritant concentrations was subsequently conducted in lidocaine-positive patients. If negative, a subcutaneous challenge with 1% lidocaine was done.

RESULTS

Thirteen of 756 patients patch tested were positive to lidocaine. Seven patients had relevant reactions to over-the-counter products containing lidocaine, 2 reacted to subcutaneous lidocaine, and 4 had incidental findings. There were no patients with positive results to intradermal testing. Three patients had delayed reactions to the subcutaneous challenge.

CONCLUSIONS

Patients with positive patch tests to lidocaine and negative results to intradermal testing and subcutaneous challenge may be safe to use lidocaine as an injectable local anesthetic in the future.

Therapeutic management of anal eczema: an evidence-based review

AIM

To conduct a systematic review of treatments for anal eczema (AE).

METHODS

We conducted a Medline search for clinical trial data for the treatment of perianal diseases including AE, including papers not published in the English language. We assessed the study reports using the system recommended by the Oxford Centre for Evidence-based Medicine. No meta-analysis was attempted.

RESULTS

The evidence base for topical treatments used to treat AE is very poor: there are very few studies and many of those that exist are of poor quality. The best evidence was found for medications that are yet to be licensed for AE. Among products with existing licences for the treatment of eczema, our assessment found some evidence to support the continued use of mild-to-moderate corticosteroids first line in most patients.

DISCUSSION

Features of the perianal region, and the fact that it is almost always occluded, mean that not all medications recommended in the general treatment guidelines for eczema are appropriate for AE. However, there are no specific treatment guidelines for these patients. This may in part be because of the lack of high-quality evidence-based medicine in this therapy area. Many frequently prescribed medications were developed and licensed many years ago, in an era when clinical trial design was not expected to be as rigorous as it is today.

CONCLUSION

This review highlights the need to conduct more high-quality clinical trials in patients with AE in order that specific guidelines for the management of this difficult proctological condition can be prepared.

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.