Sebaceous cysts are common, non-cancerous skin growths that can sometimes drain. This article explains the typical characteristics of sebaceous cyst drainage, factors influencing its duration, and when to seek medical attention.
What is a Sebaceous Cyst?
A sebaceous cyst, also known as an epidermal inclusion cyst, is a benign lump that forms just beneath the skin’s surface. These cysts typically originate when a hair follicle becomes blocked, trapping skin cells and keratin within a sac-like structure. The contents are primarily a thick, cheese-like substance composed of keratin and cellular debris, not true sebum.
These cysts often appear as smooth, movable lumps and can vary in size. They commonly develop on the scalp, face, neck, back, and trunk, but can occur almost anywhere. While generally harmless, they can sometimes cause discomfort or become inflamed.
Typical Drainage Duration and Characteristics
When a sebaceous cyst spontaneously ruptures, it may begin to drain. The material released is typically thick, pasty, and ranges in color from off-white to yellowish. This discharge often has a foul or “cheesy” odor due to the breakdown products of keratin and cell debris.
Spontaneous drainage is often prolonged and intermittent, lasting weeks or months, because the thick contents prevent complete emptying. Complete resolution rarely happens without medical intervention, as the cyst wall usually remains intact. When a healthcare provider performs an incision and drainage, the incision site typically heals within one to two weeks.
Factors Affecting Drainage Time
Several factors influence how long a sebaceous cyst drains. Larger cysts generally contain more material and may take longer to empty, whether through spontaneous rupture or medical drainage. An infected cyst will also experience prolonged drainage as the body clears the bacterial presence.
Manipulation or squeezing can worsen the situation, potentially leading to inflammation, incomplete drainage, or introducing bacteria that cause infection. If the cyst’s capsule is not entirely removed or expressed during drainage, the cyst is likely to recur and may continue to drain or refill. The completeness of the drainage process directly impacts its duration.
When to Seek Medical Help
Consult a healthcare professional if a draining sebaceous cyst shows concerning signs. Indicators of infection include increasing redness, warmth, significant pain, or swelling around the cyst. The presence of pus or a fever also signals a potential infection that requires medical assessment.
Medical attention is warranted if drainage is excessive, continuous, or does not show signs of improvement. A cyst that grows rapidly, becomes increasingly painful despite draining, or frequently recurs should also be evaluated. Professional diagnosis and treatment are important to manage complications and ensure proper healing.