To study the mechanism and risk of human skin cancer from solar light, we exposed human skin transplanted to severe combined immunodeficient mice to daily doses of UVB for periods of approximately 2 years. We have succeeded for the first time in inducing cancer and solar (actinic) keratosis in human skin by UVB. Of 18 normal skins exposed to doses of 7.3 x 10(5) to 1.8 x 10(6) J/m2, 14 actinic ...

Actinic keratoses (AK) are the most common premalignant pathology seen in dermatological practice and represent a burgeoning burden upon health services. Increasingly recognized is the damage to surrounding, perilesional skin, forming the premise for field-directed therapy. Ingenol mebutate gel is a novel agent for field-directed treatment of AK, requiring only 2 or 3 days of application. Follo...

A spectrum evaluator based on a system of four materials has been applied to the evaluation of actinic ultraviolet exposures to humans. The exposures were evaluated between early morning and near noon in summer and the actinic irradiances calculated ranged from 3 μW cm to 5 μW cm. Simultaneously, the broad band irradiances which induced the actinic exposures and/or the biologically effective ex...

Imiquimod, an immune-modulating imidazoquinoline compound, has been approved in topical formulation for the treatment of actinic keratoses, superficial basal cell carcinomas, and external genital warts. Its use in the treatment of field cancerization, in particular, has been rapidly evolving. With the recent approval of a new drug application for a new concentration, as well as generic formulat...

Lichen planus and vitiligo are common skin disorders. Colocalization which is rarely reported may consider the koebner phenomenon related to the photo damage causing initiation of lichen planus over vitiliginous skin. We report a 37-year-old mother and her 23-year-old daughter, both farmers and known cases of vitiligo with subsequent gradual onset of pruritic skin lesions of lichen planus start...

OBJECTIVE To compare the repetitive DNA patterns of human actinic keratoses and squamous cell carcinomas to determine the genetic alterations that are associated with malignant transformation. INTRODUCTION Cancer cells are prone to genomic instability, which is often due to DNA polymerase slippage during the replication of repetitive DNA and to mutations in the DNA repair genes. The progressi...

BACKGROUND Clinical diagnosis of actinic keratosis is known to have intra- and inter-observer variability, and there is currently no non-invasive and objective measure to diagnose these lesions. OBJECTIVE The aim of this pilot study was to determine if automatically detecting and circumscribing actinic keratoses in clinical photographs is feasible. METHODS Photographs of the face and dorsal...

Actinic keratosis (AK) is a common, sun-induced, pre-malignant lesion with a strong likelihood of progressing to a malignancy. The reported risk of AK progressing to squamous cell carcinoma (SCC) varies from less than 1% to 20%. Clinically, induration, pain, large size, marked hyperkeratosis, ulceration, bleeding, rapid growth, and recurrence or persistence may be markers of AK progression into...

Actinic keratoses are premalignant lesions of the skin caused by excessive sun exposure. Lesions may become mainly squamous cell carcinoma. Cryotherapy with liquid nitrogen is one of the main treatments. In order to evaluate the response of actinic keratosis to cryotherapy by histopathology, two lesions were selected in each of 14 patients with multiple actinic keratoses. In one lesion a biopsy...