Recent advances in understanding and managing contact dermatitis [version 1; referees: 3 approved]

About 20% of the general population is contact-sensitized to common haptens such as fragrances, preservatives, and metals. Many also develop allergic contact dermatitis (ACD), the clinical manifestation of contact sensitization. ACD represents a common health issue and is also one of the most important occupational diseases. Although this inflammatory skin disease is mediated predominantly by memory T lymphocytes recognizing low-molecular-weight chemicals after skin contact, the innate immune system also plays an important role. Along that line, the presence of irritants may increase the risk of ACD and therefore ACD is often seen in the context of irritant contact dermatitis. In this review article, we discuss recent progress in basic research that has dramatically increased our understanding of the pathomechanisms of ACD and provides a basis for the development of novel diagnostic and therapeutic measures. Current methods for diagnosis as well as treatment options of ACD are also discussed

Prevalence of actinic keratosis and skin cancer in a population of Dutch outdoor workers

Background: Outdoor work is associated with high and chronic exposure to solar ultraviolet radiation which might lead to an increased risk of developing skin (pre)malignancies. Prevalence of actinic keratosis (AK), basal cell carcinoma (BCC), cutaneous squamous cell carcinoma (cSCC) and cutaneous melanoma (cM) in Dutch outdoor workers (OW) has not previously been investigated. Objective: This study compares the prevalence of premalignant lesions and skin tumours in OW and matched controls (non-OW). Methods: In a population-based cohort study, prevalence of premalignant lesions and skin tumours was investigated in a group of OW (n = 841) and controls matched 1:1 by age, sex, skin colour and tendency for sunburn. Skin examinations were conducted by physicians and skin cancer history was derived from the nationwide Dutch Pathology Registry. Information on OW was obtained through interviews. Conditional logistic regression models were used to calculate odds ratios (ORs) with 95% confidence intervals (CIs) for associations between OW and BCC, cSCC, cM and (number of) AK. Results: AK was found in 22.7% of OW and 22.9% of non-OW, BCC in 14% of OW and 15.7% of non-OW, cSCC in 4.9% of OW and 3.4% of non-OW, and cM in 1.9% of OW and 2% of non-OW. There was no significant association between OW and premalignant lesions and skin tumours, with exception for developing ≥4 AKs (OR 1.3 [95% CI 1.0–1.78]). Conclusions: This study reveals high prevalence of premalignant lesions and skin tumours in a Dutch population. No association between OW and the occurrence of premalignant lesions and skin tumours was found, however, multiple AKs were more prevalent in OW.</p

Prevalence of actinic keratosis and skin cancer in a population of Dutch outdoor workers

Background: Outdoor work is associated with high and chronic exposure to solar ultraviolet radiation which might lead to an increased risk of developing skin (pre)malignancies. Prevalence of actinic keratosis (AK), basal cell carcinoma (BCC), cutaneous squamous cell carcinoma (cSCC) and cutaneous melanoma (cM) in Dutch outdoor workers (OW) has not previously been investigated. Objective: This study compares the prevalence of premalignant lesions and skin tumours in OW and matched controls (non-OW). Methods: In a population-based cohort study, prevalence of premalignant lesions and skin tumours was investigated in a group of OW (n = 841) and controls matched 1:1 by age, sex, skin colour and tendency for sunburn. Skin examinations were conducted by physicians and skin cancer history was derived from the nationwide Dutch Pathology Registry. Information on OW was obtained through interviews. Conditional logistic regression models were used to calculate odds ratios (ORs) with 95% confidence intervals (CIs) for associations between OW and BCC, cSCC, cM and (number of) AK. Results: AK was found in 22.7% of OW and 22.9% of non-OW, BCC in 14% of OW and 15.7% of non-OW, cSCC in 4.9% of OW and 3.4% of non-OW, and cM in 1.9% of OW and 2% of non-OW. There was no significant association between OW and premalignant lesions and skin tumours, with exception for developing ≥4 AKs (OR 1.3 [95% CI 1.0–1.78]). Conclusions: This study reveals high prevalence of premalignant lesions and skin tumours in a Dutch population. No association between OW and the occurrence of premalignant lesions and skin tumours was found, however, multiple AKs were more prevalent in OW.</p

Differential diagnosis of contact dermatitis: A practical-approach review by the EADV Task Force on contact dermatitis.

The diagnosis of eczema ('dermatitis') is mostly clinical and depends on the clinical history and exploratory objective findings (primary lesions, patterns). Contact dermatitis remains as an important condition in the group of eczematous disorders, with important socioeconomic and occupational relevance. Although irritant and allergic contact dermatitis have a different pathogenesis, both are characterized by a rather typical morphology, are triggered by external factors and tend to occur primarily in the area of contact with the exogenous agent. In addition, allergic and irritant dermatitis may also co-exist. The importance of diagnosing contact dermatitis, especially when allergic in nature, is both due to the possibility of avoiding the trigger, and due to its role in aggravating other skin conditions. Nevertheless, the heterogeneity of clinical presentations in daily practice may pose an important challenge for the suspicion and correct diagnosis of contact dermatitis. Furthermore, other conditions, with different pathogenesis and treatment, may clinically simulate contact dermatitis. The Task Force aims to conduct a review of the unifying clinical features of contact dermatitis and characterize its main clinical phenotypes, and its simulators, in order to contribute to an early suspicion or recognition of contact dermatitis and enable a correct differential diagnosis

Formaldehyde 2% is not a useful means of detecting allergy to formaldehyde releasers- results of theESSCAnetwork, 2015-2018

BACKGROUND Studies suggest that patch testing with formaldehyde releasers (FRs) gives significant additional information to formaldehyde 1% aq. and should be considered for addition to the European baseline series (EBS). It is not known if this is also true for formaldehyde 2% aq. OBJECTIVES To determine the frequency of sensitization to formaldehyde 2% aq. and co-reactivity with FRs. To establish whether there is justification for including FRs in the EBS. MATERIALS AND METHODS A 4-year, multi-center retrospective analysis of patients with positive patch test reactions to formaldehyde 2% aq. and five FRs. RESULTS A maximum of 15 067 patients were tested to formaldehyde 2% aq. and at least one FR. The percentage of isolated reactions to FR, without co-reactivity to, formaldehyde 2% aq. for each FR were: 46.8% for quarternium-15 1% pet.; 67.4% imidazolidinyl urea 2% pet.; 64% diazolidinyl urea 2% pet.; 83.3% 1,3-dimethylol-5, 5-dimethyl hydantoin (DMDM) hydantoin 2% pet. and 96.3% 2-bromo-2-nitropropane-1,3-diol 0.5% pet. This demonstrates that co-reactivity varies between FRs and formaldehyde, from being virtually non-existent in 2-bromo-2-nitropropane-1,3-diol 0.5% pet. (Cohen's kappa: 0, 95% confidence interval [CI] -0.02 to 0.02)], to only weak concordance for quaternium-15 [Cohen's kappa: 0.22, 95%CI 0.16 to 0.28)], where Cohen's kappa value of 1 would indicate full concordance. CONCLUSIONS Formaldehyde 2% aq. is an inadequate screen for contact allergy to the formaldehyde releasers, which should be considered for inclusion in any series dependant on the frequency of reactions to and relevance of each individual allergen

Patch test results with the European baseline series, 2019/20-Joint European results of the ESSCA and the EBS working groups of the ESCD, and the GEIDAC

BACKGROUND Continual analyses of patch test results with the European baseline series (EBS) serve both contact allergy surveillance and auditing the value of included allergens. OBJECTIVES To present results of current EBS patch testing, obtained in 53 departments in 13 European countries during 2019 and 2020. METHODS Anonymised or pseudonymised individual data, and partly aggregated data on demographic/clinical characteristics and patch test rest results with the EBS were prospectively collected and centrally pooled and analysed. RESULTS In 2019 and 2020, 22581 patients were patch tested with the EBS. Sensitization to nickel remained most common (19.8 (19.2-20.4)% positivity (95% confidence interval)). Fragrance mix I and Myroxylon pereirae yielded very similar results with 6.80 (6.43-7.19)% and 6.62 (6.25-7.00)% positivity, respectively. Formaldehyde at 2% aq. yielded almost one percentage point more positive reactions than 1% concentration (2.49 (2.16-2.85)% vs. 1.59 (1.33-1.88)); methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) and MI alone up to around 5% positives. Among the new additions, propolis was most commonly positive (3.48 (3.16-3.82)%), followed by 2-hydroxyethyl methacrylate (2.32 (2.0-2.68)%). CONCLUSIONS Ongoing surveillance on the prevalence of contact sensitization contributes to an up-to-date baseline series containing the most frequent and/or relevant contact sensitizers for routine patch testing in Europe. This article is protected by copyright. All rights reserved