Epidermoid cysts are usually asymptomatic; however, if ruptured it may closely resemble a furuncle with tenderness to palpation, erythema, and swelling. A foul-smelling yellowish cheese-like material discharged from the skin may be described.
A cyst typically has two features: the lining, and the contents. The lining of an epidermoid cyst is made up of skin cells, which secrete keratin. Keratin is the material that makes up the hair, and the outer layer of skin. The contents of an epidermoid cyst are soft and “cheese-like,” with an unpleasant smell.
It comes from the cells that form the walls of the cysts. Those cells secrete a protein, known as keratin. These cysts are also made of fat, and it's often that substance, or infection, that makes the smell, according to American Family Physician.
Sebaceous cysts normally don't hurt, but they can become tender, sore and red if they get infected. One sign of infection is redness and swelling around the cyst or foul-smelling drainage seeping out of the cyst.
The smell is from the content of the cyst, which consists of bacteria and broken down cells from human tissue. Anaerobic bacteria, a type of bacteria that thrive in low oxygen conditions in wounds, often infect HS cysts. The bacteria degrade the white cells that attack them, as well as other cells in the tissue.
It might be tempting, but don't try to pop or drain the cyst yourself. That can cause infection, and the cyst will probably come back. Keep it clean by washing with warm soap and water. Try putting a bathwater-warm washcloth on it for 20 to 30 minutes, three to four times a day, to help soothe it and speed healing.
Sebaceous carcinoma is a rare type of skin cancer that starts in your skin's oil-producing (sebaceous) glands. It's an aggressive cancer that can return after treatment. A pimple-like bump on your upper eyelid is a common symptom, but tumors can form anywhere.
Important. Do not squeeze a skin cyst. If it bursts it could become infected, or if it's already infected you might spread the infection.
Sebaceous cysts may resolve on their own. But they often come back. Most cysts don't cause problems or need treatment. But if a cyst is bothering you for any reason, see your healthcare provider.
The area around the cyst may smell bad. If the cyst breaks open, the material inside it often smells bad too. The cyst is usually firm and you can usually move it slightly if you try.
A fatty (keratinous) substance that resembles cottage cheese, in which case the cyst may be called "keratin cyst" - this material has a characteristic "cheesy" or foot odor smell. A somewhat viscous, serosanguineous fluid (containing purulent and bloody material)
It's not advisable to try draining a cyst or abscess yourself. Cyst popping at home can cause infection. Instead, keep the area clean, and make an appointment with a doctor if the area is painful or starts to drain.
Sometimes, epidermal cysts are called sebaceous cysts. This is not correct because the contents of the two types of cysts are different. Epidermal cysts are filled with dead skin cells, while true sebaceous cysts are filled with yellowish oily material. (A true sebaceous cyst is called a steatocystoma.)
Most inflamed sebaceous cysts (inflamed due to sebum) are not infected and will settle spontaneously over 4 weeks. Antibiotics, such as cephalexin or cloxacillin, are commonly used but in fact probably provide little benefit.
The best test to determine whether a cyst or tumor is benign or malignant is a biopsy. This procedure involves removing a sample of the affected tissue — or, in some cases, the entire suspicious area — and studying it under a microscope.
“I generally recommend combining salicylic acid with benzoyl peroxide and over-the-counter 1% hydrocortisone cream,” he says. “Benzoyl peroxide kills acne-causing bacteria, while salicylic acid hits dead cells from the surface of the skin and absorbs excess oil. Finally, hydrocortisone cream helps reduce inflammation.”
If a sebaceous cyst is inflamed and bothersome, steroid injections into the cyst can be used to calm and shrink it. You should never try to pop or drain a sebaceous cyst yourself, as this can cause infection. It's OK if they drain on their own, however.
After cleaning the cyst, hold a warm compress on the area for five to ten minutes. The moisture and the warmth help to encourage the substance trapped under the skin to make its way out of the hair follicle. Repeat this process up to three times per day until the cyst drains on its own.
Do not squeeze the cyst or poke it with a needle to open it. This can cause swelling, redness, and infection. Always have a doctor look at any new lumps you get to make sure that they are not serious.
During a cyst removal, the doctor will mark and numb the area around the bump. You'll get a few Lidocaine injections that may slightly sting, but that's the worst part. After that, you won't feel the procedure.