The Dark Side of the Light: Phototherapy Adverse Effects

Phototherapy is a valuable therapeutic tool in Dermatology, but there may be drawbacks. Acute and long-term adverse effects, of variable severity, include skin erythema, xerosis, pruritus, blistering, altered pigmentation, photoaging, and photocarcinogenesis. Despite concerns over the carcinogenic potential of ultraviolet radiation, most studies have not found an increased risk of non-melanoma or melanoma skin cancer in patients treated with ultraviolet B (broadband and narrowband) and ultraviolet A1 phototherapy. These are therefore considered reasonably safe treatment modalities concerning the development of skin neoplasms, although caution and further investigation are warranted. Photoprotective measures, such as avoidance of concurrent sunlight exposure and covering skin areas not afflicted with disease, or more modern strategies, including phytochemical antioxidants and exogenous DNA repair enzymes, can minimize the hazards of phototherapy. Patients submitted to phototherapeutic regimens should undergo complete, careful dermatologic examination regularly and lifelong.info:eu-repo/semantics/publishedVersio

The Dark Side of the Light: Mechanisms of Photocarcinogenesis

Ultraviolet radiation (UVR) can have a beneficial biologic impact on skin, but it is also the most significant environmental risk factor for skin cancer development. Photocarcinogenesis comprises a complex interplay between the carcinogenic UVR, skin, and the immune system. UVB is absorbed by the superficial skin layers and is mainly responsible for direct DNA damage, which, if unrepaired, can lead to mutations in key cancer genes. UVA is less carcinogenic, penetrates deeper in the dermis, and mainly causes indirect oxidative damage to cellular DNA, proteins, and lipids, via photosensitized reactions. UVR not only induces mutagenesis, altering proliferation and differentiation of skin cells, but also has several immunosuppressive effects that compromise tumor immunosurveillance by impairing antigen presentation, inducing suppressive cells, and modulating the cytokine environment. This review focuses upon molecular and cellular effects of UVR, regarding its role in skin cancer development.info:eu-repo/semantics/publishedVersio

Pyoderma Gangrenosum in a Patient with Ulcerative Colitis

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Unknown Primary Merkel Cell Carcinoma With Cutaneous Spread

The authors present the case of a woman in the seventh decade of life with medical history of: left nephrectomy for renal tuberculosis and non-Hodgkin's lymphoma treated with chemotherapy (QT) and radiotherapy. She presented with a 2-month history of non-tender, left inguinal lymph node enlargement. Positron Emission Tomography (PET)-CT -scanshowed hypermetabolic inguinal and retroperitoneal lymphadenopathies, no primary tumour. On the second dermatological examination a pink, 2 cm plaque on the anterior left knee was noted. The histopathological analysis revealed Merkel cell carcinoma. The patient underwent two lines of systemic QT, with life-threatening toxicities limiting treatment. Followed overwhelming disease progression with lymphoedema and numerous skin metastases in the left lower limb. The patient received palliative care until death. The rare incidence of such neoplasia and its uncommon clinical presentation justifies reporting this case and highlights the importance of multidisciplinary teams in the management of cancer patients.info:eu-repo/semantics/publishedVersio

Neoplastic Cutaneous Infiltration by Lymphoplasmacytic Lymphoma in a Patient with Waldenström's Macroglobulinemia

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Systemic Allergic Dermatitis Caused by Sodium Metabisulfite in Rectal Enemas

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Associação Entre Vitiligo e Halo Nevo

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