我耳珠後面腫左 紫色的 係咪斷耳瘡!?

This is an infected sebaceous cyst.
A sebaceous cyst (a form of trichilemmal cyst; also called: keratin cyst or pilar cyst; sometimes incorrectly called: epidermal cyst or epidermoid cyst (see ICD-10 L72.0)) is a closed sac or cyst below the surface of the skin that forms in a hair follicle and fills with a fatty white, semi-solid material called sebum.
The scalp, ears, back, face,and upper arms, are common sites for sebaceous cysts, though they may occur anywhere on the body except the palms of the hands and soles of the feet. As they form in hair follicles they are more common in hairier areas. They are smooth to the touch, vary in size, and are generally round in shape.
They are generally mobile masses that can consist of fibrous tissues and fluids, to a fatty, (sebaceous), substance that resembles cottage cheese, or a somewhat viscous, serosanguinous fluid, (containing purulent and bloody material). The nature of the contents of a sebaceous cyst, and of its surrounding capsule, will be determined by whether the cyst has ever been infected. At surgery a cyst can usually be excised in its entirety; poor surgical technique or previous infection leading to scarring and tethering of the cyst to the surrounding tissue may lead to rupture during excision and removal. A completely removed cyst will not recur, though if the patient has a predisposition to cyst formation further cysts may develop in the same general area.

Causes
Blocked sebaceous glands, swollen hair follicles, excessive testosterone production will cause such cysts.[1]

Treatment
Sebaceous cysts are not cancerous and do not generally require medical treatment. However, if they continue to grow, they may become unsightly, painful, infected, or all of the above. Surgical excision of a sebaceous cyst is a simple procedure to completely remove the sac and its contents. An infected cyst may require oral antibiotics or other treatment before excision.

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