Managing Contact Dermatitis Without Patch Testing.

Allergic contact dermatitis (ACD) is a common skin condition caused by contact with an exogenous agent that elicits an inflammatory response. Patch testing (PT) is considered the gold standard for diagnosing ACD. Unfortunately, PT may not be available to some patients due to insurance and financial limitations, contributing to health care disparity and leaving patients with undiagnosed, incompletely managed dermatitis that can have further detrimental health and occupational effects. For other patients, PT is precluded by lack of availability of specialist/expert care, comorbid medications, or diffuse disease. This article will present a patient with ACD and will work through the differential diagnosis and share strategies for empiric avoidance of suspected/common triggers. The epidemiology of ACD with respect to race and ethnicity, considerations for affordability of hypoallergenic products, access to testing, and the need for future research are addressed in this article.

Patient-Centered Communication Tools for the Patch Test Clinic.

Patient-centered communication positively impacts the clinical encounter. Multiple strategies exist to improve communication between providers and their patients; the application and impact of these strategies have been studied in multiple specialties, though little exists regarding communication best practices in the patch test clinic. Because the procedural components of patch testing often span the course of an entire week, effective communication with patients during the patch testing visit is important for not only technical success, but also patient understanding and experience. In this study, we highlight the value of beginning the patch testing visit with clear introductions and agenda setting, improving patient understanding and engagement through methods such as teach backs and cycles of questions and answers that create patient-provider dialogue, and using communication techniques to make expressions of empathy. We provide detailed examples regarding the application of these techniques to the patch testing process, aimed at enhancing the patch testing experience and improving clinical outcomes. Our review exemplifies how dermatologists can leverage communication tools to improve patient satisfaction and outcomes during patch testing.

The Role of Patch Testing in Evaluating Delayed Hypersensitivity Reactions to Medications.

Confirming drug imputability is an important step in the management of cutaneous adverse drug reactions (CADR). Re-challenge is inconvenient and in many cases life threatening. We review the literature on ideal patch testing technique for specific CADRs. Testing should be performed approximately 3 months after the resolution of the eruption using standard patch testing techniques. Commercially available patch test preparations are available for a minority of drugs, so in most cases, testing should be performed with the drug at various recommended concentrations and in different vehicles. Testing to all known excipients, such as dyes, vehicles and preservatives is also important. Immunosuppressive medications should be discontinued or down titrated to the lowest tolerable dose to decrease the risk of false negative reactions. We provide an overview of expert recommendations and extant evidence on the utility of patch testing for identifying the culprit drug in common CADRs and for specific drug or drug classes. Overall, there appears to be significant variability in the patch test positivity of different drugs, which is likely the result of factors intrinsic to the drug such as dermal absorption (as a function of lipophilicity and molecular size) and whether the drug itself or a downstream metabolite is implicated in the immune reaction. Drugs with high patch test positivity rates include beta-lactam antibiotics, aromatic anticonvulsants, phenytoin, and corticosteroids, among others. Patch testing positivity varies both as a function of the drug and type of CADR. The sum of the evidence suggests that patch testing in the setting of morbilliform eruptions, fixed drug eruption, acute generalized exanthematous pustulosis, and possibly also drug-induced hypersensitivity syndrome, photoallergic and eczematous reactions may be worthwhile, although utility of testing may vary on the specific drug in question for the eruption. It appears to be of limited utility and is not recommended in the setting of other complex CADR, such as SJS/TEN and leukocytoclastic vasculitis.

Update on Contact Sensitization in the Older Adult Population.

BACKGROUND: Little is known about the epidemiology of allergic contact dermatitis in the aging US population. OBJECTIVE: The aim of this study was to describe patch test results in a cohort of older adult patients evaluated in a patch testing clinic in a tertiary medical center. METHODS: This study was a retrospective analysis of patch test results of adults 65 years and older from February 2013 to December 2019. RESULTS: Data from a total of 169 patients 65 years and older were analyzed. Of these patients, 84.6% (143/169) had 1 or more positive reactions on patch testing, 84.6% (121/143) of which were felt to be clinically relevant and received a final diagnosis of allergic contact dermatitis. The most common allergen categories were fragrances (30.1%), preservatives (20.8%), metals (11.0%), medicaments (8.3%), and textile dyes (6.5%). The most common individual allergens were Myroxylon pereirae resin (balsam of Peru), hydroperoxide of linalool, methylisothiazolinone, nickel sulfate, and fragrance mix I. Personal products were by far the most common presumed source of allergen exposure. CONCLUSIONS: Allergic contact dermatitis is a common diagnosis in the older adult population, and patch testing with allergen avoidance counseling can be an important diagnostic step and potential cure for this allergic condition.

Allergic Contact Dermatitis of the Vulva.

Allergic contact dermatitis is an important diagnostic consideration in the evaluation of patients presenting with vulvar complaints. The high prevalence of contact sensitization in the vulvar region is likely multifactorial. We review the extant literature regarding key predisposing factors in the pathogenesis of vulvar allergic contact dermatitis, as well as the most commonly implicated allergens as identified by a number of retrospective studies and case series. On the basis of our findings, we provide diagnostic and therapeutic recommendations for practicing clinicians.

Hidradenitis Suppurativa: A Guide for the Practicing Physician.

Hidradenitis suppurativa is a chronic inflammatory disease of apocrine gland-bearing skin. Although immunologic derangements, genetic predisposition, obesity, and smoking are likely important factors, the pathogenesis of the disease and the effect of available treatments on disease course have not been fully elucidated. In the absence of proper treatment, chronic inflammation results in diffuse scarring and a wide array of complications, including the development of cutaneous squamous cell carcinoma. This severe and chronic disease can have detrimental effects on self-esteem and quality of life. No ideal treatment regimen has been defined, but several therapies have been found to reduce lesion severity and improve symptoms. We reviewed the literature through July 2014 for existing treatments. Published articles were obtained via systematic review of medical databases (PubMed, Embase, Google Scholar) and scrutiny of citation lists using the search terms "hidradenitis suppurativa" and "acne inversa". Given the scarce literature on treatment strategies, we also reviewed data from any case reports or prospective and retrospective studies that were located. On the basis of the existing literature, we provide an evidence-based algorithm for the management of this disease in the primary care setting. More research is needed to evaluate the comparative effectiveness of topical and systemic treatments and to better understand the pathogenesis, natural history, and subtypes of hidradenitis suppurativa.