Chronic actinic dermatitis: A 5-year clinical analysis of 488 patients in China

BACKGROUND/PURPOSE

Chronic actinic dermatitis (CAD) is a spectrum of diseases with chronic photosensitivity occurring mostly among middle-aged and older men. We seek to explore the characteristics and pathogenesis of CAD among the Chinese population.

METHODS

The medical records of 488 CAD cases diagnosed by phototesting at Huashan Hospital, Fudan University from January 2014 to December 2018 were analyzed retrospectively.

RESULTS

Among the 488 patients, 344 were male and 144 were female. 84.8% of the cases were over 40 years old at the age of onset, while the remaining with an early age of onset had a prevalence of atopic history of 21.6%. Up to 45.0% of the patients reported excessive sun exposure and outdoor activities before the initiation of symptoms. The typical skin lesions were erythema, papules and plaques laid predominantly in sun-exposed areas. 42.8% of the cases showed sensitivity to UVB only, 20.7% were both sensitive to UVA and UVB, and 18.2% had UVA sensitivity only. The most predominant photoallergens were chlorpromazine (80.1%), thimerosal (17.2%), potassium dichromate (12.7%), etc. The most prevalent patch test allergens were potassium dichromate (24.4%), thimerosal (20.5%), formaldehyde (16.8%), etc. CONCLUSIONS: CAD was more commonly seen in males over 40 years old. The action spectrum of Chinese patients is primarily in the UVB range. Exposure to excessive sunlight or contact allergens and photoallergens are important risk factors. Photobiology tests are essential in detecting photosensitivity and recognizing potential photosensitizers. Early avoidance of confirmed photoallergens and sun exposure may prevent photosensitive reactions from progressing into persistent photosensitivity.

Successful Treatment of Chronic Actinic Dermatitis with Dupilumab: A Case Report and Review of the Literature

Chronic actinic dermatitis (CAD) is a rather rare photosensitive disease characterized by a persistent eczematous eruption in sun-exposed sites. The pathogenesis of CAD has not been completely elucidated. The clinical treatment of CAD is still challenging and not standardized. Some patients with severe CAD have achieved satisfactory clinical results with dupilumab when conventional therapies have failed. We herein report the case of a 45-year-old male with severe CAD who responded rapidly to combined treatment with dupilumab (600 mg for 1 week, and then 300 mg every 2 weeks) in 2 months. The patient experienced continuous improvement and no side effects from dupilumab (300 mg every month), having ceased other systemic medications. Dupilumab could be considered as an alternative or adjunctive treatment for CAD.

Clinical and pathological findings of chronic actinic dermatitis

BACKGROUND

Chronic actinic dermatitis (CAD) is a recurrent photosensitive disease occurs predominantly in elderly men on sun-exposed areas, which seriously affect the patient's life quality. The etiology of CAD remains unknown.

METHODS

Sixty-six CAD patients, 66 atopic dermatitis (AD) patients, and 46 healthy people were enrolled into this study. Patient-level data were obtained from the electronic medical record and laboratory databases. We also obtained 29 tissue samples including 16 lichenoid lesions, 7 minimal erythematous dose (MED) analysis induced lesions, and 6 normal skin samples. Histopathologic and immunohistochemical analysis were performed.

RESULTS

In the clinical characteristics, albumin was lower and uric acid was higher significantly in patients diagnosed as CAD. The infection rate of CAD patient after skin biopsy was considerably high (23.3%). The serum allergen test was prone to be negative in CAD patients. Lymphocytes were the dominate infiltrating cells in early and late CAD lesions, while more CD4+, CD8+, CD69+, and CD103 + cells were found in the late lesions. There is no difference in CD4+/CD8 + ratio and CD69+/CD103 + ratio among groups. More mast cells were observed in the early-stage lesions, and more dendritic cell was observed in the late-stage lesions.

CONCLUSIONS

CAD patients have certain oxidative stress and are prone to be infected after skin biopsy. Serum allergen detection is of little significance for CAD diagnosis. Mast cells may be involved in the early process of CAD, while dendritic cells and tissue-resident memory T cell (TRM) may be related to the chronic process of the disease.