Keratin Levels

You see and touch keratin every day, but you probably don’t give it much thought. This protein is the building block of your hair, fingernails and outer layer of skin. Because it's durable and non-porous, it’s also a component in some nail polishes and hair products -- usually those used to straighten curls and frizz, Fitness magazine says.

Function

Keratin’s main function is protection, the Mayo Clinic notes -- especially for safeguarding your skin against infections and other harmful intrusions. Keratin is a necessary component in your body. Too little of it sometimes causes white spots on your nails; too much can lead to unhealthy or unsightly conditions.

Whiteheads

What Causes Keratin Buildup?

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Whiteheads crop up when keratin on your skin’s top layer clogs the skin’s hair follicles, Women Fitness says 2. A keratin plug plugs the hair follicle, which normally freely secretes an oily substance called sebum that keeps your skin soft and supple. When keratin clogs the follicle, sebum becomes trapped and hardens, creating a white bump. Bacteria soon start multiplying in the sebum, making your skin irritated and painful.

Keratosis Pilaris

Similar to acne, the skin condition keratosis pilaris also results in plugged hair follicles from excess keratin, the Mayo Clinic says 3. But rather than a whitehead or two, keratosis pilaris covers entire patches of skin, leaving small, scaly bumps and rough, dry patches 3.cause:

• But rather than a whitehead or two
  
• keratosis pilaris covers entire patches of skin
  
• leaving small
  
• scaly bumps
  
• rough
  
• dry patches 3

Karatosis pilaris often crops up on the thighs, arms and buttocks, leaving skin similar to sandpaper. No one has figured out the cause of keratosis pilaris, but the condition is usually not painful and tends to disappear by the time you're 30 3.

Ichthyosis Vulgaris

Hard Bumps on a Child's Skin

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Ichthyosis vulgaris, also known as fish scale or fish skin disease, is another condition caused by excess keratin, the Mayo Clinic says 4. A generic mutation leads to ichthyosis vulgaris, which results in scaly skin or actual scales that are usually grayish, brown or white 4. A flaky scalp and cracked skin in the palm and sole areas often come with the condition. Children born with ichthyosis vulgaris usually don’t show any symptoms until they are a few years old 4.

Epidermolysis Bullosa Simplex

Defective keratin-producing genes are the cause behind epidermolysis bullosa simplex, a condition most common in babies and young children, the Mayo Clinic says 5. This condition results in skin that easily blisters, sometimes at the slightest touch or friction. In addition to blistering skin, side effects of a defective keratin-producing gene sometimes include nail deformities, hair loss and blistering and scarring on the scalp.