How can I treat keratosis pilaris?

Amlactin. Keratosis pilaris is plugging of hair follicles, typically on the upper arms and thighs. It is thought to be in the spectrum of atopic dermatitis (or eczema). The roughness can be reduced temporarily by amlactin lotion, which contains 12% lactic acid. Unfortunately, there is no cure.
Exfoliants. Exfoliants such as aha (alpha-hydroxy acid) or glycolic acid, lactic acid, urea help to soften the rough bumps. Using exfoliating scrubs, body washes, moisturizers that contain these products along with a loofah on a regular basis help to minimize the bumps. They will worsen again if you stop using the products.