Dear Paula,

Since I was five or six, I have had little bumps on the backs of my upper arms. Today, I have them on the backs of my upper arms, below my elbow on the backs of my lower arms, on my hips and thighs down to the knee, and on the backs of my lower legs, halfway up my calves. They don't hurt (although dryness causes them to itch sometimes) but they are very annoying. When I scratch my skin or exfoliate particularly roughly and thoroughly, my skin gets temporarily smoother, but the bumps always come back. When I scratch one particular bump, I usually see little hairs come through the skin. I guessed that my hair was so fine that it couldn't make it through my relatively thick skin.

In the March 2002 issue of InStyle magazine, there was a "Beauty Know It All" letter about bumps on the back of your upper arms. The magazine diagnosed the problem as "Keratosis pilaris, a genetically inherited skin disorder that affects up to 40 percent of the adult population." The cause was said to be "the skin's inability to properly exfoliate itself." The recommended treatments were exfoliation with a traditional body scrub, and with a chemical exfoliant. The magazine recommended Amlactin, an inexpensive lotion that contains 12% lactic acid to help the skin exfoliate itself.
Does this sound like the proper diagnosis? If so, does the treatment sound right? Thanks for any help.

B. L., via e-mail

Dear B.L.,

The article sounds fairly right-on as far as the diagnosis is concerned. But the treatment recommendations fall short for several reasons. Keratosis pilaris is indeed very common, finding a home on the upper arms, thighs, and shoulders. Keratosis pilaris tends to be more severe during the winter months but no one is sure why that is the case and it definitely isn't consistent for everyone. Basically, the bumpy rough spots are clogged pores that sometimes get red and irritated but rarely itch. Regrettably there is no available cure or universally effective treatment, though it is generally well accepted that unclogging pores and reducing inflammation can improve matters greatly (Source: eMedicine Journal, July 2, 2001, Volume 2, Number 7).

Lactic acid (a very effective form of alpha hydroxy acid) can help exfoliate skin cells, but lactic acid isn't effective for dissolving lipids, so it can't penetrate into the pore and exfoliate the lining of the pore that is a major cause of the problem. For that, you would need a beta hydroxy acid product where the active ingredient is salicylic acid. It is also helpful to avoid soaps that can irritate skin or cause clogged pores. A gentle body shampoo is best. The recommendation to scrub away the plugs can mean you inflame the area and still leave the skin feeling rough and bumpy below the surface where the abrasive can't reach.