: 339

Chronic
Chronic paronychia is an infection of the folds of tissue surrounding the nail of a finger or, less commonly, a toe, lasting more than six weeks. It is a nail disease prevalent in individuals whose hands or feet are subject to moist local environments, and is often due to contact dermatitis. : 660  In chronic paronychia, the cuticle separates from the nail plate, leaving the region between the proximal nail fold and the nail plate vulnerable to infection. : 343  It can be the result of dish washing, finger sucking, aggressively trimming the cuticles, or frequent contact with chemicals (mild alkalis, acids, etc.). Alternatively, paronychia may be divided as follows:
Candidal paronychia is an inflammation of the nail fold produced by C. albicans. : 310 
Pyogenic paronychia is an inflammation of the folds of skin surrounding the nail caused by bacteria. : 254  Generally, acute paronychia is pyogenic, as it is usually caused by a bacterial infection. Differential
Differential diagnosis of paronychia includes:

Cellulitis is a superficial infection and presents as erythema and swelling to the affected portion of the body with no area of fluctuance. Treatment is with oral antibiotics. Whitlow or felon is a subcutaneous infection of the digital pulp space. The area becomes warm, red, tense, and very painful due to the confinement of the infection, creating pressure in the individual compartments created by the septa of the finger pad. These require excision and drainage, usually with a longitudinal incision and blunt dissection to ensure adequate drainage. Herpetic whitlow is a viral infection of the distal finger caused by HSV.
Arcus senilis (AS), also known as gerontoxon, arcus lipoides, arcus cornae, corneal arcus, arcus adiposus, or arcus cornealis, are rings in the peripheral cornea. It‘s usually caused by cholesterol deposits, so it may be a sign of high cholesterol. It is the most common peripheral corneal opacity, and is usually found in the elderly where it is considered a benign condition. When AS is found in patients less than 50 years old it is termed arcus juvenilis. The finding of arcus juvenilis in combination with hyperlipidemia in younger men represents an increased risk for cardiovascular disease. Pathophysiology
AS is caused by leakage of lipoproteins from limbal capillaries into the corneal stroma. Deposits have been found to consist mostly of low-density lipoprotein (LDL). Deposition of lipids into the cornea begins at the superior and inferior aspects, and progresses to encircle the entire peripheral cornea. The interior border of AS has a diffuse appearance, while the exterior border is well demarcated. The clear space between the exterior border and the limbus is called the interval of vogt.Bilateral AS is a benign finding in the elderly, but it can be associated with hyperlipidemia in patients less than 50 years old. Bilateral AS may also be caused by increased levels of free fatty acids in the circulation secondary to alcohol use.Unilateral AS can be associated with contralateral carotid artery stenosis or decreased intraocular pressure in the affected eye. As these are serious medical conditions, unilateral AS should be examined by a physician.