Albinism: epidemiology, genetics, cutaneous characterization, psychosocial factors

Abstract Oculocutaneous albinism is an autosomal recessive disease caused by the complete absence or decrease of melanin biosynthesis in melanocytes. Due to the reduction or absence of melanin, albinos are highly susceptible to the harmful effects of ultraviolet radiation and are at increased risk of actinic damage and skin cancer. In Brazil, as in other parts of the world, albinism remains a little known disorder, both in relation to epidemiological data and to phenotypic and genotypic variation. In several regions of the country, individuals with albinism have no access to resources or specialized medical care, and are often neglected and deprived of social inclusion. Brazil is a tropical country, with a high incidence of solar radiation during the year nationwide. Consequently, actinic damage and skin cancer occur early and have a high incidence in this population, often leading to premature death. Skin monitoring of these patients and immediate therapeutic interventions have a positive impact in reducing the morbidity and mortality associated with this condition. Health education is important to inform albinos and their families, the general population, educators, medical professionals, and public agencies about the particularities of this genetic condition. The aim of this article is to present a review of the epidemiological, clinical, genetic, and psychosocial characteristics of albinism, with a focus in skin changes caused by this rare pigmentation disorder.

Actinic keratosis: a clinical and epidemiological revision / Queratoses actínicas: revisão clínica e epidemiológica

Actinic keratoses are benign intraepithelial skin neoplasms constituted by atypical proliferation of keratinocytes that may evolve to squamous cell carcinoma. They develop in photoexposed skin areas; they are induced mainly by ultraviolet radiation and are considered cutaneous markers of chronic exposure to sunlight. They develop mainly in adults and older, fair skinned individuals, and are the fourth most common cause of dermatologic consultation in Brazil. Damage to the apoptosis pathway in photoexposed epithelium favors cellular proliferation and the permanence of the lesions. In this revision, the authors assemble the main epidemiological data regarding this disease and suggest that strategies to identify risky phenotypes, early diagnosis, adequate treatment, clinical follow-up, stimulus to skin self examination, photoeducation and photoprotection should be promoted with the aim of avoiding the progression to malignancy and also the prevention and the diagnose of concomitant neoplasms also induced by ultraviolet radiation.

Queratoses actínicas são neoplasias benignas intraepiteliais formadas por proliferações atípicas de queratinócitos com potencial de transformação em carcinoma espinocelular. Desenvolvem-se em áreas fotoexpostas da pele, são induzidas principalmente pela radiação ultravioleta e constituem marcadores de exposição solar crônica. Acometem indivíduos adultos e idosos, de fototipos claros, representando o quarto diagnóstico dermatológico mais comum no Brasil. Danos nas vias de apoptose do epitélio fotoexposto favorecem a proliferação celular e manutenção das lesões. Nesta revisão os autores reúnem os principais dados epidemiológicos sobre a doença e defendem que estratégias de identificação de fenótipos de risco, diagnóstico precoce, tratamento adequado, seguimento clínico, incentivo ao autoexame da pele, fotoeducação e fotoproteção devem ser promovidas, a fim de evitar a evolução das lesões, e também prevenir e diagnosticar neoplasias concomitantes também induzidas pela radiação solar.

Prevalência de lesões cutâneas actínicas em pacientes com carcinoma basocelular do segmento cefálico: um estudo caso-controle / Prevalence of actinic skin lesions in patients with basal cell carcinoma of the head: a case-control study

OBJETIVO: Avaliar a prevalência de lesões cutâneas actínicas em portadores de carcinoma basocelular do segmento cefálico. MÉTODOS: Foi conduzido estudo tipo caso-controle. Os casos, constituídos por pacientes com carcinoma basocelular sólido, primário, menor que dois centímetros, no segmento cefálico; e controles, por pacientes com outras dermatoses. Foram analisadas variáveis constitucionais, comportamentais e lesões actínicas. RESULTADOS: Avaliaram-se 120 casos e 360 controles. Mílio facial (OR = 2,3), leucodermia puntacta de membros superiores (OR = 2,9) e cutis romboidalis nuchae (OR = 1,8) associaram-se à neoplasia independentemente das demais variáveis, sugerindo um fenótipo de risco. Houve ainda associação com fenótipos claros, genética familiar e exposição solar cumulativa. Queimadura solar, tabagismo e alcoolismo não foram identificados como fatores de risco. O uso de fotoprotetores não evidenciou proteção; porém, o grupo controle era composto por pacientes dermatológicos, aos quais são indicados fotoprotetores regularmente. CONCLUSÃO: Lesões actínicas foram mais prevalentes em portadores de carcinoma basocelular sólido do segmento cefálico que em controles, especialmente mílio, cutis romboidalis nuchae e leucodermia puntacta, independentemente dos demais fatores de risco conhecidos.

OBJECTIVE: To evaluate the prevalence of actinic skin lesions in patients with basal cell carcinoma of the head. METHODS: A case-control study was carried out. Cases were patients with primary, solid basal cell carcinoma of the head, less than two centimeters in diameter; and as controls, patients with other dermatoses. Constitutional and behavioral variables were analyzed, as well as actinic lesions. RESULTS: One hundred twenty cases and 360 controls were evaluated. Facial milia (OR = 2.3), leukoderma punctata of the upper limbs (OR = 2.9), and cutis rhomboidalis nuchae (OR = 1.8) were associated with neoplasms regardless of other variables, suggesting a risk phenotype. There was also association with light hair and eye color phenotypes, family genetics, and cumulative sun exposure. Sunburn, smoking, and alcoholism were not identified as risk factors. The use of sunscreens showed no evidence of protection; however, the control group consisted of dermatology patients who are often prescribed sunscreens. CONCLUSION: Actinic lesions were more prevalent in patients with solid basal cell carcinoma of the head than in controls, especially milia, cutis rhomboidalis nuchae, and leukoderma punctata, regardless of other known risk factors.