Health - Boils, Cysts, Ingrown Hairs, and 11 Other Skin Mysteries Explained

Poof! A mysterious lump or bump appears on your body. What is it? How long has it been there? It's impossible to ask Dr. Google about a "lump on skin" and not lose your mind, but many times these lumps and bumps are nothing to lose sleep over. Keloids occur when scar tissue grows excessively, explains Gary Goldenberg, MD, a dermatologist and an assistant clinical professor of dermatology at the Icahn School of Medicine at Mount Sinai Hospital in New York City. 

Keloids often form around a wound or incision, but they may appear after a bad bout of acne. (They're actually one of five common acne scars.) "Keloids are red, raised and can be itchy or painful," he says. They're more common in darker skin and often show up on the ears, chest, face or back. Many different treatments work alone or together to improve keloid scarring including steroid injections to flatten the scar, cryosurgery to freeze the scar tissue so it sloughs off, laser resurfacing, and surgery, he says. "You do need realistic expectations about how much keloid scarring can be improved with any treatment."

Skin tags are exactly what they sound like—tiny, soft skin-colored growths, Dr. Goldenberg says. "They often develop around the eyelids, armpits, groin or other areas that are easily rubbed or irritated." (Before you do anything, check out this advice on skin tags.) Medically known as acrochordons, skin tags are more common if you are overweight, pregnant, or have diabetes.

They are not harmful in any way, shape or form, he says. "If they bother you, a doctor can freeze, laser, or snip them off." A boil is a firm, painful lump that can look like an over-sized pimple. It's usually caused by an infection of a hair follicle. "Boils may increase or decrease in size, or spontaneously drain, weep, or ooze," Dr. Moore says. Repeated hot packs or soaking three to four times a day usually helps. In some cases, medical attention is required to lance or drain a boil. "People with cancer, diabetes or other causes of immunocompromised should seek medical attention whenever they develop this or any other skin infection," she says.