Photo credit: http://en.wikipedia.org/wiki/Sebaceous_cyst
Patients will often come into the urgent care with a small skin lump that has become red and/or painful. Often if they think back, they might recall feeling a small nodule under the skin in that same area perhaps months or years before it became swollen and red. The epidermal inclusion cyst is one of the most common skin cysts and can occur anywhere on the body but they are more common on the face or upper body. Most of the time, these cysts do not cause any problems, but can sometimes be cosmetically unpleasing.
Other names for epidermal cysts:
1) Epidermoid cyst
2) Sebaceous cyst
3) Keratin cyst
4) Epidermal inclusion cyst
5) Infundibular cyst
Appearance: Epidermal cysts have a cyst wall that is make of skin cells of the outside layer of the skin called the epidermis. The cyst wall is like a balloon that goes down into the second layer of skin called the dermis. The cyst wall/balloon makes a protein found in the skin/nails called keratin that is usually white, cheesy or firm in consistency. It is often foul smelling as well.
Cyst Rupture: If the cyst wall ruptures underneath the skin (usually due to trauma or bumping the area unintentionally), the keratin (cheesy white material) comes out and is exposed to the surrounding tissues and is very irritating. It can make the skin become red, swollen and painful. It’s best to see your doctor instead of trying to “pop” or drain the cyst yourself. Sometimes your doctor may recommend treating you with an oral antibiotic before opening the cyst if he/she thinks that the cyst has become infected.
How epidermal cysts are removed: If the cyst needs to be removed, your doctor will try to remove the entire cyst including the cyst wall. Remember, the cyst wall is what makes the keratin (that cheesy white material inside the cyst). If the cyst wall is allowed to remain underneath the surface of your skin, it may start making more keratin which can cause the cyst to come back.
Usually we make an incision over the cyst and separate the underlying skin from the cyst wall and try to remove it in one piece. If the cyst has ruptured (which is most likely brought the patient in), the cyst is removed in a piecemeal fashion with an attempt to get all of the keratin, and cyst wall out. The doctor may irrigate the wound with sterile solution after the procedure. The skin is usually left open and not stitched. The doctor may place a small piece of packing gauze under the skin where the cyst was and then put a bandage over it. This will allow the wound to drain while it’s healing. The wound is usually examined by a medical provider every 2-3 days to check on the healing process and part or all of the packing gauze will usually be removed.
The reason that your medical provider may put some sterile gauze inside the wound and ask you to come back to be reexamined instead of just putting some stitches over the wound is because sometimes these areas can be infected with bacteria and if the skin is closed right away with sutures, the bacteria will have a small pocket under the skin to grow and form an abscess. If the wound is allowed to heal from the inside out, there is less chance of an abscess forming and wound healing can happen more quickly.
When to have a cyst removed: If it’s small and doesn’t hurt and isn’t painful/red/swollen, it probably doesn’t need to be removed. I might recommend removing a cyst if:
1) It keeps getting red and irritated or infected
2) It’s getting larger quickly
3) It’s in a place that rubs against your clothes or jewelry and gets irritated
4) If it becomes red, inflamed or painful
This document is for informational purposes only, and should not be considered medical advice for any individual patient. If you have questions please contact your medical provider.
I hope that you have found this information useful. Wishing you the best of health,
Scott Rennie, DO