You live inside of your skin, but you may not examine it very often. If your fingertips brush against a rough spot and you notice tiny, raised bumps, you may worry that you have a rash or an unusual skin condition.

Fortunately, the bumps often are keratosis pilaris, which can be itchy but otherwise harmless. If your case isn’t associated with itchiness or underlying eczema, it probably doesn’t require a trip to the doctor.

"This is an extremely common skin condition, much like acne," said Narat Eungdamrong, MD, a Cedars-Sinai dermatologist. "Most patients will have raised bumps covering a wide area, typically on the thigh, upper arms, back and sometimes the buttocks or forearm. I rarely see them on the face, except in children."

Keratosis pilaris may look like a swath of pimples, goosebumps or even plucked chicken flesh. The tiny bumps may be the same color as your skin, or they may look reddish or purple.

The condition arises when your hair follicles produce more of the protein keratin—found in skin, hair and nails—than they should.

The circumstance "forms a little bump at the site," Eungdamrong said. "Think of it as excess keratin that each hair follicle makes."

Keratosis pilaris bumps may itch if you have dry, sensitive skin or eczema. It may be itchier if you endure certain drying conditions, like whiling away time immersed in a chlorinated swimming pool or staying outside in cold, windy weather.

"The chlorine that’s used to sanitize the pool is often drying and irritating," Eungdamrong said. "With cool, dry weather, there’s less moisture in the air, and people tend to take longer, hotter showers that dry the skin."

Keratosis pilaris affects 50% to 80% of teens, as well as 40% of adults.

Read: How to Take Care of Your Skin

Some people mistake keratosis pilaris for conditions such as prickly heat, razor burn, fungal skin infections, folliculitis (infected hair follicles) or acne. But each condition differs from keratosis pilaris. For example, razor burn typically appears on the neck or bikini line, not the upper arms or thighs, and folliculitis causes pus-filled, painful bumps.

"Also, prickly heat is caused by the obstruction of sweat glands, so it occurs in areas where you’re sweating through your shirt, like the back, chest or abdomen," Eungdamrong said. "The distribution is different than it is for keratosis pilaris."

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You usually don’t need medical care for keratosis pilaris, because it’s a harmless condition. Some patients seek care because they’re itchy or they don’t like the bumps’ cosmetic appearance.

Some primary-care physicians diagnose and treat keratosis pilaris. Others refer patients to dermatologists. If you’re bothered by chronic itchiness, or if your bumps bleed, see a doctor.

"The most common type of skin cancer, basal cell carcinoma, can be a pink bump that tends to bleed, so any non-healing area should be checked," Eungdamrong said. "And if keratosis pilaris itches, it’s harmless, but if it’s associated with underlying eczema, it may require treatment."

Read: Don't delay getting a skin exam. Here's what to expect.

If your keratosis pilaris is bothersome, moisturizing with a thick emollient may help decrease itchiness. Chemical exfoliants may smooth bumpy skin. Many chemical exfoliants, which help break down bonds within dead skin cells on the skin’s surface so they will fall away, are available over the counter.

Dermatologists may recommend these chemical exfoliant ingredients:

• Salicylic acid
• Glycolic acid
• Urea
• Ammonium lactate
• Lactic acid
• Retinol
• Retinoids, which are prescribed

"Retinol and retinoids can cause dryness and irritation to the skin, so I usually have patients try them every other night to begin with, and then work their way up to using them every night, as tolerated," Eungdamrong said. "The one thing that I don’t recommend is physically exfoliating, because you can get too aggressive scrubbing."