Prevalence of positive patch test (ppt) reactions to propolis in Europe has varied with different allergen source origins. Compared with previous cycles, the North American Contact Dermatitis Group (NACDG) noted a marked increase in propolis positivity in 2019-2020. To compare propolis positivity in North American centers between 3 periods (2019, 2020, and 2021/2022), based on geographic origin and supplier. Retrospective analysis of NACDG patch test data (2019-2022) utilizing 3 different sources of propolis: Chinese propolis (Allergeaze-CPA), Chinese propolis (Chemotechnique-CPC), and Brazilian propolis (Allergeaze-BPA). Proportions of ppt reactions to propolis were: 3.7% (84/2260) to CPA in 2019, 14.7% (271/1838) to BPA in 2020, and 2.2% (66/3052) to CPC in 2021/2022. There was a statistically significant difference in prevalence of reactions for BPA compared with both CPA and CPC ( < 0.00001). When unexpected changes are noted in patch test positivity, especially with naturally derived allergens, the reasons behind those changes should be investigated. The substitution of Brazilian for Chinese propolis resulted in a significant increase in ppt reactions.

This article is an update of our previous review of propolis published in in 2013. It provides brief general information on propolis and a full update of the literature published between March 2013 and May 2025 on contact allergy to propolis, including results of testing in consecutive patients, data on testing in groups of selected patients, case reports, and case series. In addition, coreactivity to fragrances, fragrance-markers, and other compounds is presented and assessed, recent analyses of the components of the propolis materials used for patch testing are detailed, the allergens in propolis are briefly discussed, and data on the frequency of propolis used in cosmetics are provided. Special attention is paid to the sudden appearance of Brazilian propolis (Allergeaze) as patch test allergen, which caught us (and many others) by surprise. We try to elucidate the nature of positive patch tests to this material (allergic, false-positive, both?) and find an explanation for the extremely large number of positive reactions seen in various studies. We argue that propolis is used in few cosmetics and that these products are an infrequent cause of sensitization and allergic contact dermatitis. Rather, the majority may represent cross- or pseudo-cross-reactions in patients previously sensitized to fragrances. It is imperative that in the publication of all studies in which contact allergy to propolis was investigated, the source of propolis test material is specified: Chemotechnique (Chinese propolis) or Allergeaze (propolis = Chinese propolis; propolis [B] = Brazilian propolis).

Nemolizumab is approved for the treatment of moderate-to-severe atopic dermatitis in patients aged ≥12 years, combined with topical corticosteroids and/or calcineurin inhibitors, when the disease is not adequately controlled by topical prescription therapies. Given the limited duration of follow-up in clinical trials and the current lack of postmarketing surveillance data, further investigations to evaluate the long-term safety profile of nemolizumab are urgently needed. Adverse event (AE) signals were identified using disproportionality analysis with four algorithms: the reporting odds ratio (ROR), proportional reporting ratio, information component, and empirical Bayesian geometric mean. The data analyzed were from the FDA Adverse Event Reporting System, covering the period from the first quarter of 2024 to the second quarter of 2025. The three most frequently reported AEs were pruritus, rash, and headache. The top three AE signals with ROR values were eczema herpeticum, pemphigoid, and dermatitis exfoliative generalized. Specific AEs included injection site hemorrhage, injection site discoloration, eyelid edema, and urticaria. Notably, sleep disorder and eosinophil count emerged as new AEs. These findings provide a comprehensive real-world safety overview of nemolizumab, highlighting both expected and emerging risks to inform clinical monitoring and risk management strategies during patient treatment.

Chemical leukoderma (CL) is an acquired depigmentation condition caused by repeated exposure to melanocytotoxic chemicals that can occur in the presence or absence of allergic contact dermatitis (ACD). Chemicals containing aromatic or aliphatic derivatives such as phenols and catechols have been shown to have melanocytotoxic properties that contribute to the pathogenesis of CL. Lesions are clinically and histologically indistinguishable from vitiligo and can occur in the absence of preexisting inflammatory cutaneous disease or vitiligo. CL often occurs after the use of personal care products or through occupational exposure (such as personal protective equipment). It is a growing phenomenon that has affected patients worldwide and can especially have detrimental psychosocial effects on patients with skin of color because of the sharp contrast between the leukoderma and the background pigmentation of the unaffected skin. A large number of reports of ACD preceding CL in the past five decades suggest that sensitization to allergens containing both aromatic and nonaromatic compounds may be contributory to the development of contact hypersensitivity reaction followed by leukoderma weeks to months after initial exposure. The most commonly reported allergen among these case reports is para-phenylenediamine, an agent used in hair dye and frequently as a darkening agent in henna tattoos. This review provides an overview of the pathophysiology and factors related to CL after ACD or diagnostic patch testing and the allergens related to this disorder of pigmentation.

As new therapies for atopic dermatitis (AD) are developed, it is increasingly important to assess how AD impacts patient-reported outcomes. To quantify productivity loss, work impairment, and health-related quality of life (HRQOL) among individuals with different levels of AD severity. Employed adults from across Canada with a history of AD completed a web-based questionnaire. AD severity was assessed using the Patient-Oriented Eczema Measure; productivity loss, work impairment, and HRQOL were evaluated by the Valuation of Lost Productivity, Work Productivity and Activity Impairment, and Veterans RAND 12-item Health Survey (VR-12) questionnaires, respectively. The association between outcomes and AD severity was evaluated using multiple linear regression. Among the 200 participants, productivity loss increased with AD severity, but this was not statistically significant. Work impairment was greater in those with moderate (adjusted difference 13.6%[95% CI: 3.0, 24.1]) and severe to very severe AD (adjusted difference 20.5%[95% CI: 8.3, 32.7]) compared to those with no or mild AD. VR-12 health utility was lower for individuals with moderate (adjusted difference -0.08[95% CI: -0.16, -0.01]) and severe to very severe AD (adjusted difference -0.17[95% CI: -0.26, -0.08]) compared to those with mild or no AD. Greater AD severity was associated with greater work impairment and worse HRQOL.

The hygiene hypothesis suggests infections in childhood may protect against atopic dermatitis (AD). Objective: To determine the association between varicella zoster virus (VZV) infection/varicella virus vaccination (VV) in childhood and the severity of AD. The study was a comparative cross-sectional study. Demographic characteristics and clinical history of VZV and VV were collected. The severity of AD was calculated using the SCORing Atopic Dermatitis (SCORAD) severity scale. Serum varicella immunoglobulin G (IgG) titer was done. Statistical analysis was done. 234 patients having AD with almost equal representation by males and females were recruited for the study. A history of VZV infection was present in 68 patients. None of the patients gave history of VV. Serum IgG titers were done in 78 patients. Mean age was found to be 7.23 ± 4.05. Patients having a history of VZV infection had mild severity of AD. The median total number of AD episodes and the median number of hospital visits each year, median SCORAD were lower, and the median age of onset of AD and the median IgG titer of study participants were higher among patients having a history of VZV infection. There was a statistically significant negative (inverse) correlation between SCORAD and IgG titer. This is a site-limited study. There may be recall and selection bias while collecting data. SCORAD being not completely objective is another limitation. Estimation of immunoglobulin-E levels and characterization of lymphocyte-monocyte subset were not done. VZV infection in childhood prior to onset of AD is a protective factor for atopic dermatitis.

Allergic contact dermatitis (ACD) affects 15-20% of the population, with patch testing as the best diagnostic tool. However, inappropriate reimbursement models and the absence of a physician work relative value unit create financial disincentives that limit access to patch testing services. This study assessed patch test utilization among American Contact Dermatitis Society (ACDS) members to identify updated reimbursement models and to explore barriers affecting the availability of patch testing. A 20-question survey was electronically distributed to ACDS members between December 2024 and January 2025, with questions pertaining to practice type, patch testing patterns, current reimbursement structures, and financial barriers to patch testing administration. Among 76 respondents, 83% were dermatologists, with a median of 14 years in practice. Compensation varied: 41% received no payment beyond evaluation and management codes, and 38% were reimbursed via collections. 42% of respondents never conduct extended patch testing. Additionally, 42% of respondents did not accept Medicaid. Frequently cited barriers included lack of standardized billing and high no-show rates. Administrative and financial challenges continue to hinder patch testing accessibility. Standardized reimbursement models, expanded insurance coverage, and policy reforms may help improve equitable access to this critical diagnostic service, though additional barriers such as provider expertise and geographic distribution might also play important roles.