AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

Background

Keratosis pilaris (KP) is a genetic disorder of keratinization of hair follicles of the skin. It is an extremely common benign condition that manifests as small, rough folliculocentric keratotic papules, often described as chicken bumps, chicken skin, or goose bumps, in characteristic areas of the body, particularly the outer-upper arms and thighs. Although no clear etiology has been defined, KP is often described in association with other dry skin conditions such as ichthyosis vulgaris, xerosis, and, less commonly, with atopic dermatitis, including conditions of asthma and allergies. See Ichthyosis Vulgaris, Hereditary and Acquired and Atopic Dermatitis for more information.

KP affects nearly 50-80% of all adolescents and approximately 40% of adults. It is frequently noted in otherwise asymptomatic patients visiting dermatologists for other conditions. Most people with KP are unaware the condition has a designated medical term or that it is treatable. In general, KP is frequently cosmetically displeasing but medically harmless.

Overall, KP is described as a condition of childhood and adolescence. Although it often becomes more exaggerated at puberty, it frequently improves with age. However, many adults have KP late into senescence. Approximately 30-50% of patients have a positive family history. Autosomal dominant inheritance with variable penetrance has been described.

Seasonal variation is sometimes described, with improvement of symptoms in summer months. Dry skin in winter tends to worsen symptoms for some groups of patients. Overall, KP is self-limited and, again, tends to improve with age in many patients. Some patients have lifelong KP with periods of remissions and exacerbations. More widespread atypical cases may be cosmetically disfiguring and psychologically distressing.

Pathophysiology

Keratosis pilaris (KP) is a genetically based disorder of hyperkeratinization of the skin. An excess formation and/or buildup of keratin is thought to cause the abrasive goose-bump texture of the skin. In these patients, the process of keratinization (the formation of epidermal skin) is faulty. One theory is that surplus skin cells build up around individual hair follicles. The individual follicular bumps are often caused by a hair that is unable to reach the surface and becomes trapped beneath the keratin debris. Often, patients develop mild erythema around the hair follicles, which is indicative of the inflammatory condition. Often, a small, coiled hair can be seen beneath the papule. Not all the bumps have associated hairs underneath. Papules are thought to arise from excessive accumulation of keratin at the follicular orifice.

Frequency

International

Keratosis pilaris (KP) is overall a very common condition and is present worldwide. KP affects 50-80% of adolescents and approximately 40% of adults worldwide.

In India and other countries, a specific condition called erythromelanosis follicularis faciei et colli is described. This is an unusual condition with a possible genetic or other relationship to KP. Erythromelanosis follicularis faciei et colli is characterized by the triad of hyperpigmentation, follicular plugging, and erythema of the face and neck.^{1, 2}

Mortality/Morbidity

Keratosis pilaris (KP) is not associated with increased mortality or morbidity. Often, patients are bothered by the cosmetic appearance of their skin and its rough, gooseflesh texture. KP is present in otherwise healthy individuals and does not have any long-term health implications.

Race

Keratosis pilaris (KP) has no widely described racial predilection or predominance. It is commonly noted worldwide in persons of all races.

Sex

Both sexes are affected by keratosis pilaris (KP), but females may be affected more frequently than males.³

Age

Age of onset of keratosis pilaris (KP) is often within the first decade of life; symptoms particularly intensify during puberty. However, KP may manifest in persons of any age and is common in young children. Some authorities believe individuals can outgrow the disorder by early adulthood, but often this is not the case.

CLINICAL

Section 3 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

History

Keratosis pilaris (KP) patients often report a rough texture (gooseflesh appearance) and overall poor cosmetic appearance of their skin. Eruptions are usually asymptomatic, except for occasional pruritus. Many people with KP are unaware the skin condition has a designated medical term or that it is treatable. In general, KP is often cosmetically displeasing but, medically, is completely harmless. Keratosis pilaris is frequently noted in otherwise healthy, asymptomatic patients visiting dermatologists and other physicians for unrelated skin conditions.

Physical

Physical findings of keratosis pilaris (KP) are limited to the skin. Upon gross examination, the skin of the outer-upper arms and thighs is frequently affected. The skin is described as chicken skin or goose bumps. Often, 10-100 very small, slightly rough bumps are scattered in an area. Palpation may reveal a fine, sandpaperlike texture to the area. Some of the bumps may be slightly red or have an accompanying light-red halo, indicating inflammation. In some instances, scratching away the surface of some bumps may reveal a small, coiled hair.

Small (up to 1-2 mm) folliculocentric keratotic papules are noted (see Media File 1). These are small bumps centered on small hair follicles. Some associated inflammation (erythema) may be present, and lesions may be the color of the skin. Often, a small, coiled hair can be seen beneath the papule. In other instances, a keratin plug or pimplelike material may be expressed from each bump. Pustules and cysts are fairly rare. 

Commonly involved areas include posterolateral upper arms (see Media File 2), anterior thighs, buttocks, and facial cheeks. The single most characteristic area in KP is the upper-outer arms.

Causes

The etiology of keratosis pilaris (KP) is not fully known. The definite association of hyperkeratinization has been established. Of persons affected, 50-70% have a genetic predisposition. Dry skin conditions seem to exacerbate the disease. Symptoms generally tend to worsen in winter and improve in summer. Common associations include a family history of KP, ichthyosis, or atopic dermatitis.⁴ KP is more common in siblings and in twins.

DIFFERENTIALS

Section 4 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

Other Problems to be Considered

Keratosis pilaris (KP) may be associated with phrynoderma (vitamin A deficiency). Interestingly, a significant association has also been found between acquired ichthyosis and KP as common cutaneous manifestations in persons with type 1 diabetes.

KP may resemble the following uncommon skin conditions:

• Lichen Spinulosus
• Pityriasis Rubra Pilaris
• Ulerythema ophryogenes (Ulerythema)
• Ichthyosis Vulgaris
• Eruptive Vellus Hair Cysts
• Erythromelanosis follicularis faciei et colli
• Keratosis Follicularis (Darier Disease)
• Kyrle Disease
• Lichen Nitidus
• Perforating Folliculitis
• Trichostasis Spinulosa

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

Lab Studies

No specific laboratory tests aid in the diagnosis of keratosis pilaris (KP). The diagnosis of KP is very straightforward and is based on a typical skin appearance in areas such as the upper arms. A family history of KP is also very helpful because KP has a strong genetic component. The diagnosis is confirmed on the basis of the physician’s clinical examination findings. A few other medical conditions look similar to KP, and these must be excluded. 

Imaging Studies

Imaging studies are not indicated.

Procedures

Skin biopsy with histopathological examination may be useful in atypical cases.

Histologic Findings

Microscopic examination (histopathology) of keratosis pilaris (KP) lesions shows the triad of epidermal hyperkeratosis, hypergranulosis, and plugging of individual hair follicles. The upper dermis may have mild superficial perivascular lymphocytic inflammatory changes.

The individual papules in KP are thought to arise from excessive accumulation of keratin at the follicular orifice. The overlying epidermis shows mild thickening and plugging of the small follicular orifice.

TREATMENT

Section 6 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

Medical Care

In view of the described genetic predisposition and possible genetic etiology of keratosis pilaris (KP), no cure or universally effective treatment is available. Inconsistent remissions and variations with seasons and hormonal states (eg,  pregnancy⁵) are described. Although symptoms usually remit with increasing age, this is not always the case. Some cases clear spontaneously without treatment.

Many treatment options and skin care recipes are available for treating KP. Many patients have very good temporary improvement following a regular skin care program. As a general rule, treatment needs to be continuous. Because no single therapy is effective, the list of potential lotions and creams is long. Importantly, keep in mind that as with any condition, no therapy is uniformly effective in all people. Complete clearing may not be possible.

• General measures to prevent excessive skin dryness, such as using mild soap-less cleansers (eg, Dove, Cetaphil), are recommended, and lubrication is the mainstay of treatment for nearly all cases.
• Best results may be achieved with combination therapy. 
• Mild cases of KP may be improved with basic lubrication using over-the-counter moisturizer lotions such as Cetaphil, Purpose, or Lubriderm.
• Additional available therapeutic options for more involved cases of KP include lactic acid lotions (AmLactin, Lac-Hydrin), alpha hydroxy acid lotions (Glytone, glycolic body lotions, urea cream (Carmol 10, Carmol 20, Carmol 40, Urix 40), salicylic acid (Salex lotion), and topical steroid creams (triamcinolone 0.1%, Locoid Lipocream), retinoic acid products such as tretinoin (Retin-A), tazarotene (Tazorac), and adapalene (Differin). Specially mixed “designer”  compound creams with  multiple different combined ingredients can also be prescribed by physicians.
• The affected area may be washed once or twice a day with a gentle cleanser such as Dove. Acne-prone skin may benefit from more therapeutic cleansers such as GlySal, Proactiv, salicylic acid, or benzoyl peroxide.
• Lotions should be gently massaged into the affected area 2-3 times a day. Irritated or abraded skin should be treated only with bland moisturizers until the inflammation resolves.
• Occasionally, physicians may prescribe a 7- to 10-day course of a medium potency, emollient-based topical steroid cream (eg, Locoid Lipocream, Cloderm) to be applied once or twice a day for inflamed, red rash areas. Once the inflammation has remitted, the residual dry rough bumps may be treated with a routine of twice-daily application of a compounded preparation of 2-3% salicylic acid in 20% urea cream.
• Intermittent dosing of topical retinoids (eg, weekly or biweekly) seems to be quite effective and well tolerated, but usually the response is only partial. After initial clearing with stronger medications, patients may then be placed on a milder maintenance regimen.
• Persistent skin discoloration, termed hyperpigmentation, may be treated with fading creams such as hydroquinone 4%, kojic acid, and azelaic acid 15-20%. Special compounded creams for particularly resistant skin discoloration using higher concentrations of hydroquinone 6%, 8%, and 10% may also be formulated by compounding pharmacists. Higher concentrations of hydroquinone may be irritating and carry an increased risk of adverse effects, including ochronosis.
• KP may be treated with topical immunomodulators such as pimecrolimus (Elidel) or tacrolimus (Protopic). Although these products are approved for atopic dermatitis and eczema, their use would be considered off label for KP. These may be used in more resistant cases or when the patient has considerable skin redness or inflammation.
• Photodynamic therapy using aminolevulinic acid (Levulan) and blue light (417 nm) has been anecdotally reported as effective, but this successful use of off-label photodynamic therapy requires confirmation.
• Severe cases of KP have been treated orally with isotretinoin (Accutane) pills for several months. Isotretinoin is generally a very potent oral medication reserved for severe, resistant, or scarring cases of acne. Its use in KP would be considered off label and not routine.
• Vitamin D (calcipotriol) is not effective for KP, but clinical trials have found it moderately effective for ichthyosis.⁶
• As with most treatments for KP, data exist only in the form of small group observations and anecdotal reports. Because KP is generally a chronic condition that requires long-term maintenance, most therapies would require repeated or long-term use to maintain results.

Surgical Care

Minor surgical procedures such as gentle acne extractions may be useful in resistant keratosis pilaris (KP). Extractions of keratotic papules and milia are performed using a small 30-gauge needle, larger 18-gauge needle, or a small diabetic lancet to pierce the overlying skin. A comedone extractor or 2 cotton-tipped applicators can be used to extract the keratin plugs or trapped coiled hairs. Best results may be achieved with combination therapy using topical emollients and physical treatments, such as manual extraction of white heads (termed acne surgery), microdermabrasion, and chemical peels.

Microdermabrasion is a safe, minimally invasive in-office, procedure used to gently exfoliate skin. Using vacuum-assisted suction, the skin is rubbed with an abrasive particle such as fine, powdery aluminum crystals or small diamond tips. Microdermabrasion assists in removing the excess keratin and outer layers of the epidermis in a controlled manner. As with other treatments for KP, the reports on this procedure are anecdotal and from small group observations. Instead of in-office microdermabrasion, another option is in-home personal exfoliation with a loofah sponge or a commercially available pad such as Buf-Puff.

In-office, physician-performed treatments such as chemical peels; dermabrasion; microdermabrasion; photodynamic therapy; and blue-light, laser, and intense pulsed light devices may be helpful as adjunctive treatment. Because KP has no cure and no universally effective treatment is available, proceed with caution using a combination of in-office treatments and a physician-directed home maintenance skin care routine.

The Medscape Dermatologic Surgery Resource Center may be of interest.

Consultations

Consultation with a dermatologist is appropriate for refractory or widespread cases.⁷

Diet

KP has no dietary associations.

Activity

KP does not limit any patient activities.

MEDICATION

Section 7 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

The goals of pharmacotherapy for keratosis pilaris (KP) are to reduce morbidity and to prevent complications.

Drug Category: Retinoids

Retinoic acid decreases cohesiveness of follicular epithelial cells, stimulates mitotic activity, and increases turnover of follicular epithelial cells.

Drug Category: Alpha-hydroxy acids

Normal constituent of tissues and blood. Act as humectants when applied topically and may decrease corneocyte cohesion.

Drug Category: Topical Skin Product

Drug Category: Keratolytic Agent

Drug Category: Acne Products

Drug Category: Corticosteroid, Topical (medium Potency)

FOLLOW-UP

Section 8 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

Deterrence/Prevention

In patients with keratosis pilaris (KP), measures should be taken to prevent excessive skin dryness. Mild soaps and cleansers should be used. Frequent application of emollients is very beneficial.

Complications

Complications from keratosis pilaris (KP) are infrequent. However, postinflammatory hypopigmentation or hyperpigmentation and scarring may occur.

Prognosis

Overall prognosis is good. Many cases resolve with increasing age. However, others may persist into late adulthood with intermittent exacerbations and remissions.

Patient Education

Patient education should focus on the tendency for chronicity of the condition and the need for ongoing maintenance therapy. Patients should also be advised that the condition is not contagious and is not a threat to their overall health. For excellent patient education resources, visit eMedicine's Skin, Hair, and Nails Center.

MULTIMEDIA

Section 9 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

Media file 1:  Close-up view of keratosis pilaris. Keratotic follicular-based erythematous papules are noted on upper arm.
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Media file 2:  Keratosis pilaris in characteristic location on outer upper arm of a 30-year-old woman.
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Media file 3:  Classic skin-colored bumps on upper arm of young white female twin. Image courtesy of The Skin Center of Laguna.
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Media file 4:  Keratosis pilaris on the upper arm of a twin female. Image courtesy of The Skin Center of Laguna.
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Media file 5:  Keratosis pilaris bumps on arm of a white female twin. Image courtesy of The Skin Center of Laguna.
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Media file 6:  Keratosis pilaris on upper arm. Image courtesy of The Skin Center of Laguna.
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Media file 7:  Keratosis pilaris on upper arm of twin. Image courtesy of The Skin Center of Laguna.
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REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

1. Sardana K, Relhan V, Garg V, Khurana N. An observational analysis of erythromelanosis follicularis faciei et colli. Clin Exp Dermatol. May 2008;33(3):333-6. [Medline].
2. Augustine M, Jayaseelan E. Erythromelanosis follicularis faciei et colli: relationship with keratosis pilaris. Indian J Dermatol Venereol Leprol. Jan-Feb 2008;74(1):47-9. [Medline].
3. Poskitt L, Wilkinson JD. Natural history of keratosis pilaris. Br J Dermatol. Jun 1994;130(6):711-3. [Medline].
4. Mevorah B, Marazzi A, Frenk E. The prevalence of accentuated palmoplantar markings and keratosis pilaris in atopic dermatitis, autosomal dominant ichthyosis and control dermatological patients. Br J Dermatol. Jun 1985;112(6):679-85. [Medline].
5. Jackson JB, Touma SC, Norton AB. Keratosis pilaris in pregnancy: an unrecognized dematosis of pregnancy?. W V Med J. Jan-Feb 2004;100(1):26-8. [Medline].
6. Kragballe K, Steijlen PM, Ibsen HH, van de Kerkhof PC, Esmann J, Sorensen LH, et al. Efficacy, tolerability, and safety of calcipotriol ointment in disorders of keratinization. Results of a randomized, double-blind, vehicle-controlled, right/left comparative study. Arch Dermatol. May 1995;131(5):556-60. [Medline].
7. Novick NL. Practical management of widespread, atypical keratosis pilaris. J Am Acad Dermatol. Aug 1984;11(2 Pt 1):305-6. [Medline].
8. Bielan B. What's your assessment? Keratosis pilaris. Dermatol Nurs. Aug 2004;16(4):357-8. [Medline].
9. Lateef A, Schwartz RA. Keratosis pilaris. Cutis. Apr 1999;63(4):205-7. [Medline].

Article Last Updated: Sep 17, 2008