The skin is an active immune organ that functions as the first and largest site of defense to the outside environment. Serving as the primary interface between host and pathogen, the skin's early ...immune responses to viral invaders often determine the course and severity of infection. We review the current literature pertaining to the mechanisms of cutaneous viral invasion for classical skin-tropic, oncogenic, and vector-borne skin viruses. We discuss the skin's evolved mechanisms for innate immune viral defense against these invading pathogens, as well as unique strategies utilized by the viruses to escape immune detection. We additionally explore the roles that demographic and environmental factors, such as age, biological sex, and the cutaneous microbiome, play in altering the host immune response to viral threats.
Patch testing is an important diagnostic tool for suspected allergic contact dermatitis (ACD) in occupational settings.
Provide an overview of occupational skin disease (OSD) and an analysis of ...occupational ACD in North American patients undergoing patch testing between 2001and 2016.
Patients with OSD were analyzed for frequency of allergic reactions to a screening series of allergens, occupational relevance, location of skin disease, and exposure sources. Demographic, occupation, and industry information were recorded.
Of 38,614 patients evaluated, 4471 (11.6%) had OSD, of whom 3150 (70.5%) had ACD. The most common occupationally related allergens included rubber accelerators, preservatives, and bisphenol A epoxy resin. Hands (75.8%), arms (30.0%), and face (15.9%) were common sites of dermatitis. The occupations most affected were service workers and machine operators.
Our cohort may not reflect the general working population.
This study identified common occupational allergens, exposure sources, and occupations/industries at risk. This information may help the clinician evaluate and manage patients with occupational contact dermatitis.
Patch testing is an important diagnostic tool for assessment of allergic contact dermatitis (ACD).
This study documents the North American Contact Dermatitis Group (NACDG) patch testing results from ...January 1, 2019, to December 31, 2020.
At 13 centers in North America, patients were tested in a standardized manner with a screening series of 80 allergens, and, as indicated, supplemental allergens.
Overall, 4121 patients were tested; 2871 (69.7%) had at least 1 positive/allergic patch test reaction and 2095 patients (51.2%) had a primary diagnosis of ACD. The most commonly positive allergens were nickel (18.2%), methylisothiazolinone (MI) (13.8%), fragrance mix (FM) I (12.8%), hydroperoxides of linalool (HPL) (11.1%), and benzisothiazolinone (BIT) (10.4%). Compared with that of 2017-2018, prevalence of top 20 allergens statistically increased for FM I, HPL, BIT, propolis, and hydroperoxides of limonene (3.5%). For the first time, MI positivity did not increase between reporting periods. Approximately one-fifth of patients (20.3%) had ≥1 clinically relevant reaction(s) to allergens/substances not on the NACDG series.
The epidemic of MI contact allergy in North America may have reached a plateau. Patch testing using a robust screening series, and supplemental allergens as indicated, is necessary for comprehensive evaluation of ACD.
Crosstalk between T cells, dendritic cells, and macrophages in temporal leukocyte clusters within barrier tissues provides a new concept for T cell activation in the skin. Activated T cells from ...these leukocyte clusters play critical roles in the efferent phase of allergic contact hypersensitivity (CHS). However, the cytokines driving maintenance and survival of pathogenic T cells during and following CHS remain mostly unknown. Upon epicutaneous allergen challenge, we here report that macrophages produce IL-27 which then induces IL-15 production from epidermal keratinocytes and dermal myeloid cells within leukocyte clusters. In agreement with the known role of IL-15 as a T cell survival factor and growth cytokine, this signaling axis enhances BCL2 and survival of skin T cells. Genetic depletion or pharmacological blockade of IL-27 in CHS mice leads to abrogated epidermal IL-15 production resulting in a decrease in BCL2 expression in T cells and a decline in dermal CD8
T cells and T cell cluster numbers. These findings suggest that the IL-27 pathway is an important cytokine for regulating cutaneous T cell immunity.
Introduction
This real-world, cross-sectional study compared sociodemographic, clinical and treatment characteristics, and patient-reported outcomes (PROs) among racial/ethnic groups in patients with ...atopic dermatitis (AD) who are candidates for systemic therapy.
Methods
This study included adults with dermatologist- or dermatology practitioner-diagnosed AD enrolled in the CorEvitas AD Registry (July 2020–July 2021). All patients initiated systemic therapy within 12 months prior to or at enrollment or had moderate-to-severe AD (vIGA-AD
®
≥ 3 and Eczema Area and Severity Index EASI ≥ 12) at enrollment. Patients were categorized into five mutually exclusive racial/ethnic groups: non-Hispanic White, Black, Asian, Other/Multiracial, and Hispanic (any race). Patient, clinical, and treatment characteristics were captured at enrollment. Differences in means or proportions of characteristics among racial/ethnic groups were descriptively summarized using effect sizes. Adjusted prevalence ratios and mean differences were estimated (White race/ethnicity group as the reference category) with 95% confidence intervals (CI).
Results
Among 1288 patients, 64% (
n
= 822) were White, 13% (
n
= 167) Black, 10% (
n
= 129) Asian, 8% (
n
= 97) Hispanic, and 6% (
n
= 73) Other/Multiracial. In adjusted analyses, statistically more severe EASI lichenification was noted among Black compared with White patients at the head and neck (mean difference, 0.21, 95% CI 0.06, 0.36;
p
= 0.01), trunk (0.32, 0.17, 0.47;
p
< 0.001), upper extremities (0.27, 0.09, 0.44;
p
= 0.008), and lower extremities (0.39, 0.21, 0.57;
p
< 0.001). Statistically more severe EASI lichenification was observed among Asian vs White patients in certain areas (mean difference, head and neck, 0.22 0.04, 0.39,
p
= 0.01; trunk, 0.25 0.07, 0.43,
p
< 0.001; lower extremities, 0.22 0.01, 0.43,
p
< 0.001) and SCORing for AD lichenification (mean difference: 0.34 0.15, 0.52;
p
< 0.001). Significantly higher mean pruritus over the past 7 days for Black (mean difference: 0.63 0.01, 1.26 and Hispanic patients (0.60 0.11, 1.09;
p
= 0.03) vs White patients was observed. Among AD clinical features, the prevalence of facial erythema was significantly lower among Black compared with White patients (prevalence ratio = 0.38, 0.22, 0.67;
p
= 0.007).
Conclusion
Racial/ethnic differences exist in sociodemographic, clinical and treatment characteristics, disease severity, and PROs among real-world AD patients who are candidates for systemic therapy. Recognizing these variations may be of critical importance for dermatologists for the design and delivery of targeted/personalized medicine approaches.
Isothiazolinones are a common cause of allergic contact dermatitis.
To examine the prevalence of positive patch test reactions to isothiazolinones from 2017-2020 and characterize ...isothiazolinone-allergic (Is+) patients compared with isothiazolinone nonallergic (Is–) patients.
Retrospective cross-sectional analysis of 9028 patients patch tested to methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI) 0.02% aqueous, MI 0.2% aqueous, benzisothiazolinone (BIT) 0.1% petrolatum, and/or octylisothiazolinone (OIT) 0.025% petrolatum. Prevalence, reaction strength, concurrent reactions, clinical relevance, and source of allergens were tabulated.
In total, 21.9% (1976/9028) of patients had a positive reaction to 1 or more isothiazolinones. Positivity to MI was 14.4% (1296/9012), MCI/MI was 10.0% (903/9017), BIT was 8.6% (777/9018), and OIT was 05% (49/9028). Compared with Is–, Is+ patients were more likely to have occupational skin disease (16.5% vs 10.3%, P <.001), primary hand dermatitis (30.2% vs 19.7%, P <.001), and be >40 years (73.1% vs 61.9%, P <.001). Positive patch test reactions to >1 isothiazolinone occurred in 44.1% (871/1976) of Is+ patients. Testing solely to MCI/MI would miss 47.3% (611/1292) of MI and 60.1% (466/776) of BIT allergic reactions.
Retrospective cross-sectional study design and lack of follow-up data.
Sensitization to isothiazolinones is high and concurrent sensitization to multiple isothiazolinone allergens is common.
Personal care products (PCPs) are commonly responsible for allergic contact dermatitis and irritant contact dermatitis. PCP use was historically associated with females, but male-targeted PCPs are ...increasingly being marketed.
To characterize and compare males with PCP-related contact dermatitis (MPCPs) and females with PCP-related contact dermatitis (FPCPs).
This was a retrospective cross-sectional analysis of North American Contact Dermatitis Group data (1996-2016).
Four thousand six hundred eighty of 16,233 men (28.8%) and 12,730 of 32,222 (39.5%) women had a PCP identified as a source of irritant contact dermatitis or a positive patch test reaction. The proportion of PCP-related dermatitis in both sexes significantly increased (>2.7-fold) over the decade of study. Compared with FPCPs, a larger proportion of MPCPs were older or had trunk or extremity dermatitis (P < .0001). MPCPs were twice as likely to have soaps as a source while FPCPs were twice as likely to have hair care products (P < .0001). The most common PCP-related North American Contact Dermatitis Group allergens for both sexes were methylisothiazolinone (MPCP 28.8% and FPCP 21.5%), fragrance mix I (MPCP 22.3% and FPCP 20.1%), balsam of Peru (MPCP 18.5% and FPCP 14.1%), quaternium-15 (MPCP 16.1% and FPCP 12.3%), and paraphenylenediamine (MPCP 11.5% and FPCP 11.1%).
Patient population referred for suspected contact dermatitis.
PCP-related dermatitis is increasing. Sites of involvement and relevant PCP sources are distinct between sexes. Male and female variation in exposure history may explain differences in reactivity to some allergen groups.
Ammonium persulfate (APS), an oxidizing agent used in hair products, manufacturing, and pool/spa water, can cause skin reactions, including allergic contact dermatitis.
To characterize positive patch ...test reactions to APS (2.5% petrolatum).
Retrospective analysis of patients tested to the North American Contact Dermatitis Group screening series from 2015 to 2018.
Of 10,526 patients, 193 (1.8%) had positive patch test reactions to APS. Compared with APS-negative patients, APS-positive patients were significantly more likely to be male (43.2% vs 28.0%; P < .0001); have primary hand dermatitis (30.2% vs 22.0%; P = .0064), scattered generalized dermatitis (25.5% vs 17.9%; P = .0064), or trunk dermatitis (8.9% vs 4.9%; P = .0123); and have dermatitis that is occupationally related (22.2% vs 10.9%; P < .0001). More than half of the APS-positive reactions were currently relevant (57.0%); 19 (9.8%) were related to occupation, especially hairdressers (68.4%). Swimming pools/spas (23.3%) and hair care products (19.2%) were the most common sources of APS.
Immediate reactions and follow-up testing were not captured.
The proportion of patients positive to APS was 1.8%. APS positivity was significantly associated with male sex and hand dermatitis. Swimming pool/spa chemicals were important sources of APS exposure.
Alkyl glucosides are nonionic surfactants that are increasingly used in personal care products.
To characterize positive patch test reactions to decyl glucoside (5% petrolatum, tested 2009-2018) and ...lauryl glucoside (3% petrolatum, tested 2017-2018).
Retrospective analysis of patients tested by the North American Contact Dermatitis Group.
Of 24,097 patients patch tested to decyl and/or lauryl glucoside, 470 (2.0%) had positive reactions. Compared with glucoside-negative patients, glucoside-positive patients had higher odds of occupational skin disease (13.4% vs 10.1%; P = .0207), history of hay fever (38.5% vs 31.6%; P = .0014), atopic dermatitis (39.0% vs 28.6%; P < .0001), and/or asthma (21.8% vs 16.5%; P = .0023). Most glucoside reactions (83.9%) were currently relevant. The most common source was personal care products (63.0%), especially hair products (16.5%) and skin cleansers (15.2%). Of 4933 patients tested to decyl and lauryl glucoside, 134 (2.7%) were positive to 1 or both; 43.4% (43 of 99) of decyl-positive patients were also positive to lauryl glucoside and 55.1% (43/78) of lauryl glucoside patients were also positive to decyl glucoside.
The cohort predominantly reflects a referral population, and follow-up after testing was not captured.
Glucoside positivity occurred in 2.0% of the tested patients. Reactions were often clinically relevant and linked to personal care products. Cross-reactivity was >40%.
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