Keratosis Pilaris

Key Points
Common skin condition which typically affects the upper arms, though it may appear on cheeks, thighs, forearms and upper back
Exact cause is unknown, though it is known to be a genetic disorder
Consists of rough keratotic (horn-like) plugs within hair follicles, which may be red, brown or skin colored

Keratosis pilaris (KP) is a very common skin condition. It is estimated that 30- 40% of people in the U.S. may have KP. With such high rates some consider KP a normal skin variant. It typically presents as rough, horny plugs in the hair follicles of the upper arms, cheeks, thighs, trunk or buttocks . Lesions may be white, red, brown, or skin tone in color. A background of redness is often present in the areas affected. People with KP tend to have more trouble with dry and/or sensitive skin and have a higher incidence of atopic dermatitis (eczema). It most commonly appears on the upper arms, but also develops on the cheeks or thighs with some frequency. Less commonly, the condition may develop on the upper back or forearms.

Keratosis pilaris also has several variants that are much less common. In these variants, the presentation/findings differ from the primary form of the condtion. These findings include depressed scars of the cheeks, eyebrow involvement, and alopecia (hair loss). The condition is typically harmless.

While the cause is genetic, the exact trigger which causes keratosis pilaris is unknown. It typically develops during the affected person's childhood or teen years and is usually not a bother until it becomes a cosmetic issue. Overweight persons, those of celtic descent, and persons with a history of atopic dermatitis or ichtyosis may be at increased risk of developing the condition. Keratosis pilaris is less severe in warmer, more humid climates.

Differential Diagnosis (Other conditions with similar appearance)
Acne Vulgaris
Lichen Nitidus
Lichen Spinulosus
Eruptive Vellus Hair Cysts
Folliculitis
Pityriasis rubra pilaris
Keratosis Follicularis (Darier disease)
Trichostasis spinulosa

Diagnosis
Key Points
Diagnosis based on appearance of the affected area and an examination of family history
Biopsy may be performed in some cases

Keratosis pilaris is typically diagnosed based on the characteristic appearance of the condition in conjunction with a clinical examination of the affected person's family history. In atypical presentations or presentations which appear similar to other conditions, biopsy and other testing of lesions may be performed.

Treatment
No cure for the condition exists
Treatment is not typically required, as the condition is harmless
Goal of treatment is the alleviation of symptoms
OTC Options: Non-soap based cleansers, emollient creams containing urea, salicylic or alphahydroxy acids

As keratosis pilaris is harmless, treatment is generally not required, and because of its genetic roots, no cure exists. Certain measures, including the use of non-soaped based cleansers, emollient creams containing urea, salicylic or alphahydroxy acids, and filing or abraiding the affected area with a rough implement, such as a pumice stone, may prove helpful in alleviating symptoms. Additionally, health care professionals may prescribe topical retinoids. For the surrounding redness occasionly laser therapies (pulsed dye, IPL) may be used to lessen the color.