The seasonal distribution in the onset of polymyalgia rheumatica (PMR) was determined in 58 patients with the disease and compared with that in 44 patients affected by rheumatoid arthritis of elderly onset (EORA). Thirty six (62%) cases of PMR developed during May to August; by contrast, only 14 (31%) cases of EORA developed in the same months, this latter disease failing to show any seasonal c...

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...

Atypical fibroxanthoma (AFX) is an uncommon, fibrohistiocytic tumor of the skin that occurs due to actinic damage in the elderly (1). AFX rarely affects eyelid (2). It appears as solitary nodule that smaller than 2 cm (3). Boynton was the first to describe a case of AFX involving the eyelid in the literature (2). Aggresive recurrence was reported in few AFX cases, despite the benign nature of t...

Melanin is one of the most important pigments which exist ubiquitously from microorganisms to plants and animals. It is secreted by melanocyte cells and determines the color of skin and hair in mammalians. It protects the skin from photocarcinogenesis by absorbing UV sunlight and removing reactive oxygen species (ROS) (Gupta, 2006; Kim, 2005; Sapkota, 2011). It is formed by enzymatically cataly...

Inherited molecular defects in nucleotide excision repair genes cause the autosomal recessive condition xeroderma pigmentosum. Xeroderma pigmentosum is characterized by photo-hypersensitivity of sun-exposed tissues, and by a several thousand-fold increase in the risk of developing malignant neoplasms of the skin and of the eyes. Mutations in xeroderma pigmentosum genes that regulate nucleotide ...