eMedicine Specialties > Dermatology > Environmental

Corns: Differential Diagnoses & Workup

Author: Daniel J Hogan, MD, Clinical Professor of Internal Medicine (Dermatology), NOVA Southeastern University; Investigator, Hill Top Research, Florida Research Center
Coauthor(s): Amy Lynn Basile, DO, MPH, Sun Coast Hospital/Largo Medical Center, Largo, Florida
Contributor Information and Disclosures

Updated: Jan 18, 2008

Differential Diagnoses

Black Heel (Calcaneal Petechiae)
Poroma
Calcinosis Cutis
Warts, Nongenital
Callus
Dermatologic Manifestations of Neurologic Disease
Gout

Other Problems to Be Considered

Porokeratosis plantaris discreta
Keratosis punctata
Palmoplantar keratoderma (acquired or hereditary)
Foreign body
Morton neuroma
Synovitis

Workup

Laboratory Studies

No routine laboratory tests are necessary to evaluate a patient with corns.3 Diabetes mellitus, tertiary lues, and other causes of neuropathy should be excluded.

Imaging Studies

Radiographs of the feet in a weight-bearing position are useful for identifying bony prominences and the presence of underlying pathology contributing to foot pain.16 However, a physical examination may be sufficient to evaluate smaller toe abnormalities.16

Other Tests

Pressure studies (eg, pedobarography) may help define the exact location of increased plantar pressure.3

Histologic Findings

Corns demonstrate epidermal hyperplasia with a thick and compact stratum corneum. Whereas calluses demonstrate only orthokeratosis, parakeratosis may be present in corns, and biopsy specimens demonstrate an endophytic cup shape. The granular cell layer may be decreased or absent.5,6 The dermis may occasionally show fibrosis with hypertrophied nerves and scar tissue replacing subcutaneous fat.5

More on Corns

Overview: Corns
Differential Diagnoses & Workup: Corns
Treatment & Medication: Corns
Follow-up: Corns
Multimedia: Corns
References
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References

  1. Freeman DB. Corns and calluses resulting from mechanical hyperkeratosis. Am Fam Physician. Jun 1 2002;65(11):2277-80. [Medline].

  2. Murphy GA. Lesser Toe Abnormalities: Corns (Helomata and Clavi). In: Canale ST, ed. Canale: Campbell's Operative Orthopaedics. 10th. St. Louis, Mo: Mosby; 2003:4063-5.

  3. Singh D, Bentley G, Trevino SG. Callosities, corns, and calluses. BMJ. Jun 1 1996;312(7043):1403-6. [Medline].

  4. Snider RK. Corns and Calluses. In: Greene WB, ed. Essentials of Musculoskeletal Care. 2nd ed. Rosemont, Ill: American Academy of Orthopaedic Surgeons; 2001:437-41.

  5. DeLauro TM, DeLauro NM. Corns and Calluses. In: Wolff K, Goldsmith LA, Katz SI, Gilchrest BA, Paller AS, Leffell DJ, eds. Fitzpatrick's Dermatology in General Medicine. 7th ed. New York, NY: McGraw-Hill; 2008:97.

  6. Kennedy CTC, Burd DAR. Mechanical and Thermal Injury. In: Burns T, Breathnach SM, Cox N, Griffiths CE, eds. Rook's Textbook of Dermatology. 7th ed. London, England: Blackwell Science; 2004:22.

  7. Williams ML, Elias PM. Enlightened therapy of the disorders of cornification. Clin Dermatol. Jul-Aug 2003;21(4):269-73. [Medline].

  8. Dunn JE, Link CL, Felson DT, Crincoli MG, Keysor JJ, McKinlay JB. Prevalence of foot and ankle conditions in a multiethnic community sample of older adults. Am J Epidemiol. Mar 1 2004;159(5):491-8. [Medline].

  9. Menz HB, Morris ME. Footwear characteristics and foot problems in older people. Gerontology. Sep-Oct 2005;51(5):346-51. [Medline].

  10. Black JR, Hale WE. Prevalence of foot complaints in the elderly. J Am Podiatr Med Assoc. Jun 1987;77(6):308-11. [Medline].

  11. Benvenuti F, Ferrucci L, Guralnik JM, Gangemi S, Baroni A. Foot pain and disability in older persons: an epidemiologic survey. J Am Geriatr Soc. May 1995;43(5):479-84. [Medline].

  12. Habif TP. Warts, Herpes Simplex and other Viral Infections. In: Clinical Dermatology: A Color Guide to Diagnosis and Therapy. 4th ed. St. Louis, Mo: Mosby; 2004:374-5.

  13. Mann RA, DuVries HL. Intractable plantar keratosis. Orthop Clin North Am. Jan 1973;4(1):67-73. [Medline].

  14. Coughlin MJ, Kennedy MP. Operative repair of fourth and fifth toe corns. Foot Ankle Int. Feb 2003;24(2):147-57. [Medline].

  15. Menz HB, Zammit GV, Munteanu SE. Plantar pressures are higher under callused regions of the foot in older people. Clin Exp Dermatol. Jul 2007;32(4):375-80. [Medline].

  16. Coughlin MJ. Common causes of pain in the forefoot in adults. J Bone Joint Surg Br. Aug 2000;82(6):781-90. [Medline].

  17. Sage RA, Webster JK, Fisher SG. Outpatient care and morbidity reduction in diabetic foot ulcers associated with chronic pressure callus. J Am Podiatr Med Assoc. Jun 2001;91(6):275-9. [Medline].

  18. Cordoro KM, Ganz JE. Training room management of medical conditions: sports dermatology. Clin Sports Med. Jul 2005;24(3):565-98, viii-ix. [Medline].

  19. Foster A, Edmonds ME, Das AK, Watkins PJ. Corn cures can damage your feet: an important lesson for diabetic patients. Diabet Med. Dec 1989;6(9):818-9. [Medline].

  20. Balkin SW. Silicone injection for plantar keratoses. Preliminary report. J Am Podiatry Assoc. Jan 1966;56(1):1-11. [Medline].

  21. Balkin SW. Injectable silicone and the foot: a 41-year clinical and histologic history. Dermatol Surg. Nov 2005;31(11 Pt 2):1555-9; discussion 1560. [Medline].

  22. Field LM. Letter: injectable silicone for painful interdigital neurovascular clavi and verrucae. Dermatol Surg. Dec 2006;32(12):1535. [Medline].

  23. Narins RS, Beer K. Liquid injectable silicone: a review of its history, immunology, technical considerations, complications, and potential. Plast Reconstr Surg. Sep 2006;118(3 Suppl):77S-84S. [Medline].

  24. Richards RN. Calluses, corns, and shoes. Semin Dermatol. Jun 1991;10(2):112-4. [Medline].

  25. Dockery GL, Nilson RZ. Intralesional injections. Clin Podiatr Med Surg. Jul 1986;3(3):473-85. [Medline].

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Further Reading

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Keywords

clavus, clavi, mechanical hyperkeratosis, soft corns, hard corns

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Contributor Information and Disclosures

Author

Daniel J Hogan, MD, Clinical Professor of Internal Medicine (Dermatology), NOVA Southeastern University; Investigator, Hill Top Research, Florida Research Center
Daniel J Hogan, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Dermatology, American Contact Dermatitis Society, and Canadian Dermatology Association
Disclosure: Nothing to disclose.

Coauthor(s)

Amy Lynn Basile, DO, MPH, Sun Coast Hospital/Largo Medical Center, Largo, Florida
Amy Lynn Basile, DO, MPH is a member of the following medical societies: American Medical Association, American Osteopathic Association, and American Osteopathic College of Dermatology
Disclosure: Nothing to disclose.

Medical Editor

Richard K Scher, MD, Professor of Dermatology, University of North Carolina
Richard K Scher, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Dermatology, American College of Cryosurgery, American College of Physicians, American Dermatological Association, American Geriatrics Society, American Medical Association, Association of Military Surgeons of the US, International Society for Dermatologic Surgery, New York Academy of Sciences, Noah Worcester Dermatological Society, Rhode Island Medical Society, and Society for Investigative Dermatology
Disclosure: Nothing to disclose.

Pharmacy Editor

David F Butler, MD, Professor of Dermatology, Texas A&M University College of Medicine; Chair, Department of Dermatology, Director, Dermatology Residency Training Program, Scott and White Clinic, Northside Clinic
David F Butler, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Dermatology, American Medical Association, American Society for Dermatologic Surgery, American Society for MOHS Surgery, Association of Military Dermatologists, and Phi Beta Kappa
Disclosure: Nothing to disclose.

Managing Editor

Jeffrey Meffert, MD, Assistant Clinical Professor of Dermatology, University of Texas Health Science Center-San Antonio
Jeffrey Meffert, MD is a member of the following medical societies: American Academy of Dermatology, American Medical Association, Association of Military Dermatologists, and Texas Dermatological Society
Disclosure: Nothing to disclose.

CME Editor

Catherine Quirk, MD, Clinical Assistant Professor, Department of Dermatology, Brown University
Catherine Quirk, MD is a member of the following medical societies: Alpha Omega Alpha and American Academy of Dermatology
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.

 
 
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