Background During coronavirus disease 2019 (COVID-19) pandemic, various adverse skin reactions to long-term mask wearing have been reported. Objective We aimed to assess the clinical features of mask-induced dermatoses and recommend prevention and treatment options. Methods From April to August 2020, questionnaires including preexisting skin disorders, patients’ reported mask-related symptoms, their daily mask wearing duration and frequency, types of masks used, whether they are health care workers, and demographic information were distributed to patients of 12 hospitals. Dermatologists assessed skin lesions, confirmed diagnosis, and recorded treatment modalities. Results Itchiness was the most frequent symptom, mostly affecting the cheeks. Most common skin disease was new-onset contact dermatitis (33.94%), followed by new-onset acne (16.97%) and aggravation of preexisting acne (16.97%). Daily wearing (p=0.018) was significantly associated with new-onset contact dermatitis. More than half of the patients with preexisting skin problems experienced aggravation while wearing masks. Longer duration (more than 6 hours/day, p=0.043) and cotton masks (p<0.001) significantly increased acne flare-up. Healthcare workers had a higher incidence of skin disease. Skin lesions were generally mild and well tolerated with topical agents. Limitations Effect of seasonal characteristics and other risk factors were not assessed. The patients were visiting dermatologic clinics and had interest in their skin status. Thus, a selection bias may exist. Conclusion Mask-induced/triggered dermatoses contribute to increase the dermatological burden during pandemic.

Psoriasis is a chronic inflammatory skin disease occurring worldwide. Initially viewed as a keratinocyte disorder, psoriasis is now recognized to involve a complex interplay between genetic predisposition, environmental triggers, and a dysregulated immune system, with a significant role of CD4⁺ T cells producing IL-17. Recent genetic studies have identified susceptibility loci that underscore the importance of innate immune responses, particularly the roles of myeloid cells, such as dendritic cells, macrophages, and neutrophils. These cells initiate and sustain inflammation through cytokine production triggered by external stimuli. They influence keratinocyte behavior and interact with adaptive immune cells. Recent techniques have further revealed the heterogeneity of myeloid cells in psoriatic lesions, highlighting the contributions of less-studied subsets, such as eosinophils and mast cells. This review examines the multifaceted roles of myeloid innate immune cells in psoriasis, emphasizing their functional diversity in promoting psoriatic inflammation. It also describes current treatment targeting myeloid innate immune cells and explores potential new therapeutic strategies based on the functional characteristics of these subsets. Future research should focus on the detailed characterization of myeloid subsets and their interactions to develop targeted treatments that address the complex immune landscape of psoriasis.

An enzyme-linked immunosorbent assay (ELISA) was developed to detect organophosphorus pesticides using a phage-borne peptide that was isolated from a cyclic 8-residue peptide phage library. The IC₅₀ values of the phage ELISA ranged from 1.4 to 92.1 μg L⁻¹ for eight organophosphorus pesticides (parathion-methyl, parathion, fenitrothion, cyanophos, EPN, paraoxon-methyl, paraoxon, fenitrooxon). The sensitivity was improved 120- and 2-fold compared to conventional homologous and heterologous ELISA, respectively. The selectivity of the phage ELISA was evaluated by measuring its cross-reactivity with 23 organophosphorus pesticides, among which eight were the main cross-reactants. The spike recoveries were between 66.1% and 101.6% for the detection of single pesticide residues of parathion-methyl, parathion and fenitrothion in Chinese cabbage, apple and greengroceries, and all of the coefficients of variation were less than or equal to 15.9%. Moreover, the phage ELISA results were validated by gas chromatography. The results indicate that isolating phage-borne peptides from phage display libraries is an alternative method for the development of a heterologous immunoassay and that the developed assay has a lower limit of detection than the chemically synthesized competitor assay.

Jung SK, et al. Ann Dermatol. 2014 Apr;26(2):184-188. http://dx.doi.org/10.5021/ad.2014.26.2.184