Epidermal Sebaceous Cyst Inflamed and Ruptured
Inflamed epidermal cysts are warm, red, boggy and tender on palpation. This inflammation is due to a foreign body reaction to the keratin within the cyst. Furuncles have a similar appearance. Prior to rupture, the pressure beneath the skin creates intense pain and discomfort. These cysts can rupture and drain on their own, but often need to be incised by a physician to speed up this process. When incised, the keratinous debris may be trapped or loculated, and require manipulation with a curette or scalpel to be released.
Once the cyst is incised or ruptures spontaneously, sterile, purulent material and malodorous keratinous debris drains to the surface. This tends to rapidly relieve the pain and discomfort. If the inflammatory response is brisk enough to destroy the cyst wall, then it is unlikely the cyst will recur. More often, the inflammation subsides, and the cyst recurs. Scarring often follows rupture, which makes the cyst more difficult to remove.