An arsenical keratosis is a growth of keratin on the skin caused by arsenic,: 725  which occurs naturally in the earths crust and is widely distributed in the environment, Arsenical compounds are used in industrial, agricultural, and medicinal substances. Arsenic is also found to be an environmental contaminant in drinking water (well water) and an occupational hazard for miners and glass workers. : 640   Arsenic may also causes other conditions including: Bowens disease, cardiovascular diseases, developmental abnormalities, neurologic and neurobehavioral disorders, diabetes, hearing loss, hematologic disorders, and various types of cancer. Arsenical keratoses may persist indefinitely, and some may develop into invasive squamous cell carcinoma. Metastatic arsenic squamous cell carcinoma and arsenic-induced malignancies in internal organs such as the bladder, kidney, skin, liver, and colon, may result in death. Signs and symptoms
Books talk about diffuse ketarosic neoformations in palms and plants, which can evolve into basal cell carcinoma. These neoformations are usually yellowish. Pathophysiology
Arsenite impairs nucleotide excision repair, and it may also affect gene expression by increasing or decreasing DNA methylation. The high affinity of arsenic for sulfhydryl groups makes keratin-rich cells (e.g., epidermal keratinocytes) a sensitive target for arsenic-induced toxicity. Arsenic has been shown to alter epidermal keratinocyte differentiation processes, induce overexpression of growth factors, and enhance proliferation of human keratinocytes. Treatment
A chelating agent (e.g., dimercaprol) may be helpful to correct acute arsenic exposure, but it has minimal or no effect for patients who had arsenic exposure a long time ago.
Aminoaciduria occurs when the urine contains abnormally high amounts of amino acids. In the healthy kidney, the glomeruli filter all amino acids out of the blood, and the renal tubules then reabsorb over 95% of the filtered amino acids back into the blood.In overflow aminoaciduria, abnormally high concentrations of amino acids in the blood plasma overwhelm the resorptive capacity of the renal tubules, resulting in high concentrations of amino acids in the urine. This may be caused by congenital disorders of amino acid metabolism, for example, phenylketonuria, or may be secondary to liver disease.In renal aminoaciduria, the renal tubules are unable to reabsorb the filtered amino acids back into the blood, causing high concentrations of amino acids in the urine. This may be caused by a defect in the transport proteins in the renal tubule, for example, as occurs in Hartnup disease, or may be due to damage to the kidney tubule, for example, as occurs in Fanconi syndrome. References


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