Diseases of the Nails #6
Melanonychia is a brown or black pigmentation of the nail plate. It most often occurs because of increased production of melanin by melanocytes in the nail matrix. It is more common in darkly pigmented individuals and may be found in almost 100% of African Americans over the age of 50 years. There are 2 types of melanonychia: diffuse and longitudinal. Distinction depends upon the extent of discoloration. It may be caused by a number of different conditions, including melanocytic hyperplasia in melanoma (shown), lentigo, melanocytic nevi, physiologic causes (including darker skin tone and pregnancy), local factors (such as trauma, carpal tunnel, and ultraviolet light), systemic diseases (including hyperthyroidism, Addison's disease, systemic lupus erythematosus, and vitamin B12 deficiency), and dermatologic disorders (such as psoriasis vulgaris, progressive systemic sclerosis, and lupus erythematosus), or iatrogenically by medication, especially chemotherapeutic agents and antibiotics. Patients are typically asymptomatic; treatment is aimed at correction of the underlying process.
http://www.medscape.com/features/slideshow/nail-diseases?src=nl_slide
www.DEPSYL.com
http://back2basicnutrition.com
http://bionutritionalresearch.olhblogspace.com/
No comments:
Post a Comment