Keratosis Pilaris (KP) is an inherited skin disorder of hyperkeratosis which affects about 50% of the population in varying degrees of severity.

The Fancy Medical Summary

Keratosis pilaris is the result of 1-mm folliculocentric papules plugging the hair follicles. It results from a buildup of the protein keratin in the follicle's opening. Small, coiled hairs are often found in these papules and as they grow the papule may become irritated, fill with pus and acquire a red color.

In English

For one reason or another, people with KP have plugged hair follicles. It is thought the plugs could be from keratin buildup or an outer layer of skin that is unusually resistant to shedding. The most common locations for plugging are the backs of the upper arms, cheeks and/or sides of the jaw bone and the front of the thighs. Dry skin tends to exacerbate the problem, so KP can almost completely disappear in summer for mild cases and only be present in the winter months of some climates. In general the overall condition of the skin is poor and rough. Oftentimes the disorder is found in conjunction with eczema (dermatitis). While a purely cosmetic disorder, it is often psychologically distressing for the more severe sufferers. The gene for KP is dominate but there are cases in which it doesn't manifest itself or is very mild. Symptoms of keratosis pilaris generally start before age 10 and intensify during the teenage years which results in sometimes being mistaken for acne when it is present on the face.

How is it diagnosed and treated?

The appearance of keratosis pilaris is well known to any good dermatologist and is often diagnosed on this point alone, but diagnosis is often only the first of many frustrating steps. There is no cure for keratosis pilaris, only treatment which must be continuous in order for constant relief. Anything that will soften and/or remove the top layer of skin will help. Most commonly regimens for treatment include urea based products for skin softening and glycolic acid, lactic acid and retinoids (Vitamin A derivatives) for helping the skin shed more easily. Very mild cases may find complete symptom relief with just scrubbing the areas with a rough cloth or sponge to be sufficient, possibly in conjunction with lotion to alleviate any resulting dry skin. If eczema is also present, treating the eczema also can help with KP. Successful treatment requires a long term commitment to finding a regimen that works for the patient. Often the condition fades with age and can even seem to completely disappear. Keratosis pilaris is more common in women than men and doesn't seem to be more common in one race or another.

Personal Experience

I've suffered from medium to severe keratosis pilaris for as long as I can remember. While most prevalent on my upper arms, it's also present on my lower arms, jaw bone and from time to time I find evidence of it on my legs. It's clear that I inherited it from my mother, who only outgrew it in her late forties. My brother also has keratosis pilaris as well as eczema, and finds relief in eczema treatments. My mother and I have long found relief in vitamin A derivatives known as retinoids, Retin A specifically. Retin A, even in the smallest possible doses, is found by most to be to abrasive on the skin and often times it's quickly abandoned since the skin is often left raw and tender and requires religious daily use of extra strength sun screen. On my legs I've found shaving is enough to eliminate practically every trace of it, but I also can't skip more than a day of shaving since the resulting buildup is enough to cause rashes when I attempt to shave again. While poor overall skin condition is often associated with KP, I've found my unaffected skin to be in fine condition but since I tend to use Retin A in excess on most exposed areas of my body this is likely a product of that overuse. I've long been told that those with keratosis pilaris never suffer from severe acne, which I'd consider to be a far worse fate that somewhat scaly skin and reduced body hair (due to trapped hairs) any day. Without treatment I've found my skin to grow rather scaly and sometimes assume a purple-red tinge in the areas with the greatest buildup. For those with somewhat more vanity than myself I'd imagine it could be rather distressing, but I find with treatment it's not terribly noticeable and the treatments can often improve the overall condition of unaffected skin if applied there.

Sources:
Personal Experience
Alai, Nili N. Keratosis Pilaris. eMedicine. 1 July 2004 <http://www.emedicine.com/derm/topic211.htm>
Keratosis Pilaris. MayoClinic.com 1 July 2004 <http://www.mayoclinic.com/invoke.cfm?id=AN00611>
Keratosis Pilaris Redding Dermatology Medical Group. 1 July 2004 <http://www.reddingdermatology.com/keratosispilaris.htm>