eMedicine Specialties > Pediatrics: General Medicine > Dermatology

Keratosis Pilaris

Author: Mark A Crowe, MD, Assistant Clinical Instructor, Department of Medicine, Division of Dermatology, University of Washington School of Medicine
Coauthor(s): Steven J Escobar, MD, Fellow, Division of Pulmonary and Critical Care Medicine, Naval Medical Center, San Diego
Contributor Information and Disclosures

Updated: Dec 4, 2007

Introduction

Background

Keratosis pilaris is an extremely common and benign disorder of keratinized hair follicles. The disease is characterized by grouped, horny, keratotic follicular papules predominantly located on the extensor surfaces of the proximal limbs, most commonly of the posterolateral upper arms and anterior thighs. It is usually asymptomatic except for its cosmetic appearance. Treatment is marginally effective and only provides temporary relief.

Pathophysiology

Apparently because of lack of proper desquamation of keratinocytes, the follicular orifice becomes plugged with keratin and results in a keratotic papule. A variable degree of perifollicular erythema occurs.

Frequency

United States

Significant individual variation is observed in the prominence and severity of keratosis pilaris, which affects 42% of the population. Some studies estimate that keratosis pilaris affects 50-80% of all adolescents. The disorder has a familial relationship, which is consistent with autosomal dominant transmission.

Frequency is increased, reported at 74%, in individuals with ichthyosis vulgaris. Many older reports claim an increased incidence with atopic dermatitis, but more recent studies do not demonstrate this association. Hormonal influence may occur because a high prevalence and intensity of keratosis pilaris is noted during puberty and in women with hyperandrogenism.

International

Incidence is similar to that observed in the United States.

Mortality/Morbidity

Keratosis pilaris is a benign disorder; treatment in most cases requires simple reassurance and general skin care recommendations. Many patients find lesions cosmetically unappealing and, therefore, seek treatment. Occasionally, they may become secondarily infected because of scratchy, tight-fitting clothing or abrasive self-therapy, in which case treatment of the infection is necessary. A significant inflammatory component may be present and may be relieved with topical steroid therapy. Treatment of the noninflamed horny papules can be difficult because they have proven resistant to most modes of therapy.

Race

No evidence of racial predilection exists.

Sex

The inflammatory form of keratosis pilaris is more prevalent in females.

Age

Fifty-one percent of cases are diagnosed in people in the first decade of life, 35% in the second, 12% in the third, and 2% in the fourth.

Clinical

History

  • The patient may report groups of keratotic papules, which feel rough and prickly. The patient may describe them as persistent, rough goose bumps. They are not painful or significantly pruritic in most patients.
  • About half of all affected patients notice a worsening of symptoms in the winter months.
  • These lesions tend to improve after a few years.

Physical

  • Keratosis pilaris alba is the more common variant and is characterized by small gray-white papules with a negligible inflammatory component.
  • Keratosis pilaris rubra has a significant inflammatory component, and thus patients present with small erythematous papules. More widespread areas of skin are involved. This variation is most conspicuous during the winter months.
  • Observe for small, horny, follicular papules with (ie, rubra) or without (ie, alba) surrounding erythema.
  • Most commonly, lesions occur on the posterolateral upper arms and anterior thighs. Less commonly, lesions involve the face, buttocks, and trunk.
  • In involved areas, lesions are extensive, monomorphic, and very evenly spaced.
  • A fine hair may pierce the papules, or hair may be found coiled up within the keratin plug.
  • The keratin plug cannot be expressed with pressure.

Causes

Etiology is unknown, although it may be due to a disorder of corneocyte adhesion that prevents normal desquamation in the area around the follicle.

More on Keratosis Pilaris

Overview: Keratosis Pilaris
Differential Diagnoses & Workup: Keratosis Pilaris
Treatment & Medication: Keratosis Pilaris
Follow-up: Keratosis Pilaris
Multimedia: Keratosis Pilaris
References
[ CLOSE WINDOW ]

References

  1. Poskitt L, Wilkinson JD. Natural history of keratosis pilaris. Br J Dermatol. Jun 1994;130(6):711-3. [Medline].

  2. 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].

  3. Barth JH, Wojnarowska F, Dawber RP. Is keratosis pilaris another androgen-dependent dermatosis?. Clin Exp Dermatol. Jul 1988;13(4):240-1. [Medline].

  4. Callaway SR, Lesher JL. Keratosis pilaris atrophicans: case series and review. Pediatr Dermatol. Jan-Feb 2004;21(1):14-7. [Medline].

  5. Clark SM, Mills CM, Lanigan SW. Treatment of keratosis pilaris atrophicans with the pulsed tunable dye laser. J Cutan Laser Ther. Sep 2000;2(3):151-6. [Medline].

  6. Di Lernia V, Ricci C. Folliculitis spinulosa decalvans: an uncommon entity within the keratosis pilaris atrophicans spectrum. Pediatr Dermatol. May-Jun 2006;23(3):255-8. [Medline].

  7. Dogra S, Kumar B. Epidemiology of skin diseases in school children: a study from northern India. Pediatr Dermatol. Nov-Dec 2003;20(6):470-3. [Medline].

  8. Ehsani A, Namazi MR, Barikbin B, Nazemi MJ. Unilaterally generalized keratosis pilaris. J Eur Acad Dermatol Venereol. May 2003;17(3):361-2. [Medline].

  9. Gerbig AW. Treating keratosis pilaris. J Am Acad Dermatol. Sep 2002;47(3):457. [Medline].

  10. 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].

  11. Lateef A, Schwartz RA. Keratosis pilaris. Cutis. Apr 1999;63(4):205-7. [Medline].

  12. Marqueling AL, Gilliam AE, Prendiville J, Zvulunov A, Antaya RJ, Sugarman J. Keratosis pilaris rubra: a common but underrecognized condition. Arch Dermatol. Dec 2006;142(12):1611-6. [Medline].

  13. Novick NL. Practical management of widespread, atypical keratosis pilaris. J Am Acad Dermatol. Aug 1984;11(2 Pt 1):305-6. [Medline].

  14. Owen WR, Wood C. Disseminate and recurrent infundibulofolliculitis. Arch Dermatol. Feb 1979;115(2):174-5. [Medline].

  15. Ravikumar BC, Balachandran C, Shenoi SD, et al. Disseminate and recurrent infundibulofolliculitis: response to psoralen plus UVA therapy. Int J Dermatol. Jan 1999;38(1):75-6. [Medline].

  16. Rook A, Wilkinson DS, Ebling FJG, et al. Disorders of keratinization. In: Textbook of Dermatology. Oxford, England: Blackwell Publishers; 1986:1435-6.

  17. Sallakachart P, Nakjang Y. Keratosis pilaris: a clinico-histopathologic study. J Med Assoc Thai. Jul 1987;70(7):386-9. [Medline].

  18. Zouboulis CC, Stratakis CA, Gollnick HP, Orfanos CE. Keratosis pilaris/ulerythema ophryogenes and 18p deletion: is it possiblethat the LAMA1 gene is involved?. J Med Genet. Feb 2001;38(2):127-8. [Medline]. [Full Text].

[ CLOSE WINDOW ]

Further Reading

[ CLOSE WINDOW ]

Keywords

keratosis pilaris alba, keratosis pilaris rubra, goose bumps, hair follicle, keratinized hair follicles, keratotic papule, perifollicular erythema, ichthyosis vulgaris, atopic dermatitis, hyperandrogenism, erythematous papules, corneocyte adhesion, hyperkeratosis, hypogranulosis

[ CLOSE WINDOW ]

Contributor Information and Disclosures

Author

Mark A Crowe, MD, Assistant Clinical Instructor, Department of Medicine, Division of Dermatology, University of Washington School of Medicine
Mark A Crowe, MD is a member of the following medical societies: American Academy of Dermatology and North American Clinical Dermatologic Society
Disclosure: Nothing to disclose.

Coauthor(s)

Steven J Escobar, MD, Fellow, Division of Pulmonary and Critical Care Medicine, Naval Medical Center, San Diego
Steven J Escobar, MD is a member of the following medical societies: American College of Physicians and Undersea and Hyperbaric Medical Society
Disclosure: Nothing to disclose.

Medical Editor

Kevin P Connelly, DO, Clinical Assistant Professor, Department of Pediatrics, Division of General Pediatrics and Emergency Care, Virginia Commonwealth University; Medical Director, Paws for Health Pet Visitation Program
Kevin P Connelly, DO is a member of the following medical societies: American Academy of Pediatrics, American College of Osteopathic Pediatricians, and American Osteopathic Association
Disclosure: Nothing to disclose.

Pharmacy Editor

Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine.com, Inc
Disclosure: Pfizer Inc Stock Investment from broker recommendation

Managing Editor

Robert A Schwartz, MD, MPH, Professor and Head of Dermatology, Professor of Medicine, Professor of Pediatrics, Professor of Pathology, Professor of Preventive Medicine and Community Health, UMDNJ-New Jersey Medical School
Robert A Schwartz, MD, MPH is a member of the following medical societies: Alpha Omega Alpha, American Academy of Dermatology, American College of Physicians, and Sigma Xi
Disclosure: Nothing to disclose.

CME Editor

Merrily P M Poth, MD, Professor, Department of Pediatrics and Neuroscience, Uniformed Services University of the Health Sciences
Merrily P M Poth, MD is a member of the following medical societies: American Academy of Pediatrics, Endocrine Society, and Lawson-Wilkins Pediatric Endocrine Society
Disclosure: Nothing to disclose.

Chief Editor

Dirk M Elston, MD, Director, Department of Dermatology, Geisinger Medical Center
Dirk M Elston, MD is a member of the following medical societies: American Academy of Dermatology
Disclosure: Nothing to disclose.

 
 
HONcode

We subscribe to the
HONcode principles of the
Health On the Net Foundation

All material on this website is protected by copyright, Copyright© 1994- by Medscape.
This website also contains material copyrighted by 3rd parties.

DISCLAIMER: The content of this Website is not influenced by sponsors. The site is designed primarily for use by qualified physicians and other medical professionals. The information contained herein should NOT be used as a substitute for the advice of an appropriately qualified and licensed physician or other health care provider. The information provided here is for educational and informational purposes only. In no way should it be considered as offering medical advice. Please check with a physician if you suspect you are ill.