Exposure to air pollution and incidence of atopic dermatitis in the general population: A national population-based retrospective cohort study.

BACKGROUND: To date, little evidence is available to determine whether atopic dermatitis (AD) can be caused by exposure to air pollutants, including gases and particulate matter. OBJECTIVE: We aimed to evaluate the relationship between air pollutants and incidence of AD using the National Health Insurance Service-National Sample Cohort database. METHODS: We included 209,168 subjects from the general population previously not diagnosed with AD between 2008 and 2013. Long-term average concentration of air pollutants before diagnosis was calculated for each subject. RESULTS: For 1,030,324 person-years, incident cases of AD were observed in 3203 subjects. There was a significant positive association between incidence of AD and long-term average concentration of particulate matter smaller than 2.5 µm in diameter (hazard ratio [HR], 1.420; 95% CI, 1.392-1.448; for 1 µg/m3), particulate matter smaller than 10 µm in diameter (HR, 1.333, 95% CI, 1.325-1.341; for 1 µg/m3), sulfur dioxide (HR, 1.626; 95% CI, 1.559-1.695; for 1 parts per billion), nitrogen dioxide (HR, 1.200; 95% CI, 1.187-1.212; for 1 parts per billion), and carbon monoxide (HR, 1.005; 95% CI, 1.004-1.005; for 1 parts per billion) after adjusting for age, sex, income, comorbid diseases, and meteorologic variables. LIMITATIONS: The National Health Insurance Service database lacks detailed information on individual subjects. CONCLUSIONS: This study demonstrated that long-term exposure to air pollutants, including gases and particulate matter, is an independent risk factor for developing AD.

Metastatic Histiocytic Sarcoma with Secondary Involvement of the Skin: A Case Report.

Histiocytic sarcoma (HS) is a rare malignant neoplasm of presumed hematopoietic origin, showing morphologic and immunophenotypic evidence of histiocytic differentiation. A 61-year-old woman presented with an abdominal mass. She had a history of HS in both adrenal glands. The tumour cells of the left adrenal gland were very large epithelioid cells with abundant eosinophilic cytoplasm and large, round-to-oval nuclei. Similarly, the cutaneous lesion of the skin was composed of polygonal cells with well-defined cell borders and high nuclear/cytoplasm (N/C) ratios. Immunohistochemically, both tumours were positive for histiocyte-associated antigens but negative for epithelial, melanocyte, lymphoid, dendritic, and Langerhansl nuclei. Similarly, the cutaneous lesion of the skin was composenose correctly. It is important to recognise the morphological features and immunohistochemical characteristics of metastatic cells in order to achieve accurate diagnoses.

Primary Cutaneous Solitary Fibrous Tumor on the Back.

Solitary fibrous tumors (SFT) are uncommon mesenchymal tumors. SFT have several synonyms including localized fibrous tumor, benign mesothelioma, localized fibrous mesothelioma, and submesothelial fibroma. SFT usually occur in the pleura or other serosal surfaces, but SFT can also develop in extrapleural areas including the nasal cavity, orbit, retroperitoneum, and pelvis. Cutaneous SFT is extremely rare, and more likely to occur in the head and neck region. Histologically, this tumor can mimic a variety of benign and malignant tumors such as dermatofibroma, dermatofibrosarcoma protuberans, spindle cell lipoma or other mesenchymal tumors. Most cases of SFT show non-aggressive clinical courses, with low recurrence rates. Herein, we describe a case of primary cutaneous SFT which presented with huge mass on the back.