Epidermoid cysts, also called sebaceous, keratin, or epithelial cysts, are small, hard lumps that develop under the skin. These cysts are common. They grow slowly. They do not cause other symptoms and are nearly never cancerous. Epidermoid cysts are often found on the face, head, neck, back, or genitals. They can range in size from 1/4 inch to 2 inches across. They look like a small bump, are tan to yellow in color, and are filled with thick, smelly matter. They do not cause any pain and can usually be ignored.
To diagnose epidermoid cysts, a physician will examine the bump and surrounding skin, as well as take a medical history. They will ask for details on how long the bump has been present and whether it has changed over time. Physicians can usually diagnose an epidermoid cyst by examination only, but sometimes an ultrasound or a referral to a dermatologist is needed to confirm the diagnosis.
Blackheads are a type of comedo. Comedones occur when the pores in the skin become plugged with dead skin cells and an oily, protective substance known as sebum. The top of the blackhead, which is visible on the surface of the skin, has a dark color. Normally, hair grows from hair follicles in the pores, and the sebum-producing sebaceous glands lie underneath.
Sebaceous filaments look like blackheads, but they are different. They can appear on the nose. They tend to be smaller, appear in groups, and feel flat to the touch. Sebaceous filaments are glands that channel the flow of sebum through the pores. Unlike blackheads, they are not a form of acne.
Cleansing: Special scrubs for gently exfoliating the face can help. Look for those that are fragrance-free and for sensitive skin, and avoid anything that makes your skin overly dry. While it is important to dry up the skin by decreasing excessive oil production, drying it too much may make matters worse due to stimulating the extra production of oil by the glands. Azelaic acid, salicylic acid, and benzoyl peroxide are also available in both prescription and over the counter (OTC) forms for non-inflammatory acne. These are topical treatments, applied directly to the skin.