Chronic actinic dermatitis

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

“…Although the exact mechanism of CAD has not been entirely elucidated, it is generally believed that the pathogenesis of CAD is due to a delayed‐type hypersensitivity to UV‐induced allergens or endogenous photosensitive substances 22 . One hypothesis posits that the photoallergic reaction begins with the antigenized skin constituents, where hapten covalently binds to an endogenous protein in a UVA‐dependent way and then leads to a delayed‐type hypersensitivity response.…”

“…One hypothesis posits that the photoallergic reaction begins with the antigenized skin constituents, where hapten covalently binds to an endogenous protein in a UVA‐dependent way and then leads to a delayed‐type hypersensitivity response. After the photoallergy progressively becomes CAD, UVB and UVA alone may trigger the immune response without the hapten as the endogenous carrier protein will be able to form the antigenic photoproducts continuously 22 . Another postulated theory is that there is cross‐reactivity between a photoallergen and endogenous antigens in CAD patients, and therefore the endogenous antigen allows the immune response initiated by a photoallergen to persist even though the photoallergen is no longer present 23 .…”

“…Although the exact mechanism of CAD has not been entirely elucidated, it is generally believed that the pathogenesis of CAD is due to a delayed-type hypersensitivity to UV-induced allergens or endogenous photosensitive substances. 22 One hypothesis posits that the photoallergic reaction begins with the antigenized skin constituents, where hapten covalently binds to an endogenous protein in a UVA-dependent way and then leads to a delayed-type hypersensitivity response. After the photoallergy progressively becomes CAD, UVB and UVA alone may trigger the immune response without the hapten as the endogenous carrier protein will be able to form the antigenic photoproducts continuously.…”

“…After the photoallergy progressively becomes CAD, UVB and UVA alone may trigger the immune response without the hapten as the endogenous carrier protein will be able to form the antigenic photoproducts continuously. 22 Another postulated theory is that there is cross-reactivity between a photoallergen and endogenous antigens in CAD patients, and therefore the endogenous antigen allows the immune response initiated by a photoallergen to persist even though the photoallergen is no longer present. 23 Besides excessive light exposure, occupational exposure to contact allergens/photoallergens, including construction materials, metal, and petroleum products, were frequently found in CAD patients in our study.…”

Photosensitive Dermatitis Induced by Nivolumab/Ipilimumab Combination Therapy in a Patient with Malignant Melanoma

“…In this case, the patient developed severe skin erythema during NIV/IPI therapy. From the clinical distribution of the erythema, his medication history, hypersensitivity to UVA and histopathological features ( 3 ), a diagnosis of photosensitive dermatitis was considered. Since the patient received no oral medication during NIV/IPI therapy, the possibility of hypersensitivity against external antigens with oral administration was excluded.…”