A Clinical Analysis On 68 Cases Of Chronic Actinic Dermatitis And Detection Of The Expression Of AIM2 Inflammasome In Skin Lesions For CAD And Its Clinical Significance

Objectives:To evaluate the clinical,pathological,photobiology features of patients with chronic actinic dermatitis(CAD),strenthen the understanding of the disease.Analyzed the expresstion of absent in melanoma(AIM2)in skin lesions for CAD,to preliminarily explore the possible role of AIM2 inflammasome in the pathogenesis of CAD and its clinical significance.Methods:Collected the clinical data of 68 CAD patients diagnosed in the dermatology department of the first affiliated hospital of kunming medical university from 2018 to 2019,as well as histopathology,minimal erythema dose(MED)and photo-patch test.Assessed the clinical severity for CAD patients,deteted transepidermal water loss(TEWL)in sun light exposure areas skin lesions and normal skin adjacent to lesions used by skin physiological function meter.Biopsies were performed on the skin lesions of patients in sun light exposure areas.The expression of AIM2 in 30 CAD lesions was detected by immunohistochemistry,and 15 samples of normal skin tissues of healthy people in corresponding area after cosmetic surgery served as the control.Results:Among the 68 CAD patients,62 were males and 6 were females,with an average age of 61.1 ± 11.7 years old,an average onset age of 55.7 ± 13.2 years old,and the course of disease of 4.8 ± 4.9 years.There were 60 cases of skin lesions involved sun-exposed areas,and 8 cases had extension to non-exposed areas.The clinical severity of CAD patients:7 mild cases,37 moderate cases and 24 severe cases The histological features were mainly epidermal sponge edema and varying degrees of lymphocyte and tissue cell infiltration around the vessels in the superficial to middle layer of the dermis,with eosinophilic and plasmocyte infiltration.MED test:UVA-MED decline 44 cases,UVB-MED decline 33 cases,both decline 27 cases.Simultaneously,17 patients were photoallergic contact reactions to sunscreen products and nonsteroidal anti-inflammatory drugs.The level of TEWL in sun light exposure areas skin lesions obviously elevated than that of normal skin adjacent to lesions.And the expression of AIM2 in CAD biopsies was significantly higher than that in the control group.Conclusions:CAD tends to occur in middle-aged and elderly men and usually lasts for several years.The clinical features were chronic eczematoid lesions with lichenification at sun-exposed areas,and the clinical severity of CAD patients was mainly moderate to severe.Its histopathology demonstrated eczematous features and skin biopsies is helpful for CAD diagnosis.Positive results of MED and photo-patch tests were common,and photobiological examination should be given to CAD patients as far as possible.CAD patients have impaired skin barrier function and the expression levels of AIM2 were significantly increased in lesions,possibly indicating that the role for AIM2 inflammasome in sustained chronic inflammation of CAD.