Sun exposure (UVB, UVA, and blue-violet visible light) in ordinary daily situations Dear Editor, Solar radiation is essential to human life; in addition to promoting warmth and well-being, it interacts with biological tissues causing metabolic changes, oxidative stress, and deoxyribonucleic acid (DNA) mutation. Different wavelengths elicit specific effects in the skin, such as sunburn, erythema, vitamin D synthesis, carcinogenesis, immunosuppression, photoaging, modulation of skin microbioma, and melanogenesis. 1,2The intensity of solar radiation that reaches the skin varies with altitude, latitude, the season of the year, reflective surfaces (e.g., water, grass, or snow), shadow, clothing, sunscreen use, length of exposure, and the time of day. Furthermore, the biological effect of sun exposure in the skin differs individually according to melanin pigmentation, genetic predisposition (e.g., the ability to repair DNA), photosensitizing drugs, antioxidant capacity, and skin disorders that are influenced by solar radiation. [3][4][5][6]

Infantile melanoma: early diagnosis by total body mapping in dysplastic nevus syndrome total em síndrome do nevo displásico RESUMO O melanoma é uma neoplasia rara na população pediátrica, sendo ainda mais rara em crianças menores de 10 anos. O mapeamento corporal total constitui método não invasivo e de baixo custo, capaz de aumentar a acurácia diagnóstica na avaliação de lesões pigmentadas, principalmente em pacientes de alto risco. Relatamos um paciente de nove anos de idade com síndrome do nevo displásico, no qual uma lesão apresentou mudança sutil (assimetria de estruturas) no seguimento de seis meses. A exérese da lesão resultou em melanoma com Breslow 1mm e linfonodo-sentinela negativo. O mapeamento corporal total reduz o número de exéreses desnecessárias e permite o diagnóstico de melanomas em estágios iniciais e potencialmente curáveis, especialmente em crianças e pacientes com fatores de risco como síndrome do nevo displásico. O caso foi reportado devido à raridade da neoplasia na faixa etária e para demonstrar a importância da dermatoscopia digital seriada no diagnóstico precoce de melanoma nessa população. Palavras-chave: Dermoscopia; Melanoma; Síndrome do nevo displásico ABSTRACT Melanoma is a rare neoplasm in the pediatric population, and it is even rarer in children under 10 years of age. Total body mapping constitutes a low-cost and non-invasive method that increases diagnostic accuracy in evaluating pigmented lesions, especially in high-risk patients. We reported the case of a 9-year boy with dysplastic nevus syndrome, in which one lesion presented a subtle change (asymmetry of structures) within a 6-months follow-up. Its excision resulted in melanoma with a Breslow thickness of 1 mm and a negative sentinel lymph node. Total body mapping reduces the number of unnecessary excisions. It allows diagnosis of melanomas in early and potentially curable stages, especially in children and patients with risk factors such as dysplastic nevus syndrome. We report this case due to the rarity of the neoplasia in this age group and also to demonstrate the importance of sequential digital dermoscopy in early diagnosis of melanoma in this population.