eMedicine Specialties > Dermatology > Environmental

Clavus

Author: Nanette Silverberg, MD, Assistant Clinical Professor, Department of Dermatology, Columbia University School of Medicine; Director of Pediatric Dermatology, Department of Dermatology, St Luke's Roosevelt Hospital Center, Maimonides Medical Center and Beth Israel Medical Center
Contributor Information and Disclosures

Updated: Jun 26, 2009

Introduction

Background

Clavus is a thickening of the skin due to intermittent pressure and frictional forces. These forces result in hyperkeratosis, clinically and histologically. This extensive thickening of the skin may result in chronic pain, particularly in the forefoot; in certain situations, this thickening may result in ulcer formation. The word clavus has many synonyms and innumerable vernacular terms, some of which are listed in the Table below; these terms describe the related activities that have induced clavus formation.

Synonyms include the following: callosity, a hyperkeratotic response to trauma; corn, heloma, or a circumscribed hyperkeratotic lesion that may be hard (ie, heloma durum) or soft (ie, heloma molle); and callous, callus, or a diffusely hyperkeratotic lesion. Localized callosities of the soles, which do not resolve, are termed plantar callus, heloma, tyloma, keratoma, or plantar corn.1 When callosities occur over 1 or more lateral metatarsals, they are termed intractable plantar keratoses.2

Clinically, all these lesions look like hyperkeratotic or thickened skin. Maceration and secondary fungal or bacterial infections are a common overlying feature in heloma molle and diabetes. Plantar helomas tend to have a central keratin plug, which, when pared, reveal a clear, firm, central core. The most common sites for clavus formation are the feet, specifically the dorsolateral aspect of the fifth toe for heloma durum, in the fourth interdigital web of the foot for heloma molle, and under the metatarsal heads for calluses.3

Clavus Formation Named for Specific Etiology or Location

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Table
Vernacular TermLocationAssociation
Jeweler's callus, cherry pitter's thumb, 4 cameo engraver's corn 5 ThumbDigital changes, including callosities related to repetitive use of fine jeweler's instruments, which also may be seen with the use of cherry-pitting tools
Weight lifter's callus 6 Callosities over the palmar metacarpophalangeal jointsCaused by the friction of weight-lifting apparatus (This also may be seen in athletes who participate in crew.)
Prayer callus 78 Callosity on the foreheadFrom kneeling prayer with the hands on the forehead
Cigarette lighter's thumb 9 Hyperkeratosis of the radial aspect of the thumbCaused by excessive cigarette lighter flicking
Knuckle pads 10 Hyperkeratosis over the knucklesCaused by boxing training
Russell sign 11 Callosities of the dorsum of the hand over the metacarpophalangeal and interphalangeal jointsCaused by the friction involved with self-induced emesis in bulimia nervosa
Screwdriver operator's clavus 12 Palmar surface of the handOccurs at the site of contact with a screwdriver handle
Spine bumpsHyperkeratosis over the spinal columnCaused by dancing with spinning on one's back
Hairdresser's handFirst finger on dominant handCallus formation at the site of friction caused by scissors around the first finger on the dominant hand
Sucking calluses 13 Lip, hand, or foot of a newbornCallus formation at the site of an area of suction on the lip, hand, or foot of a newborn
Vamp disease 14 FeetClavus formation due to wearing tight high-heeled shoes
Vernacular TermLocationAssociation
Jeweler's callus, cherry pitter's thumb, 4 cameo engraver's corn 5 ThumbDigital changes, including callosities related to repetitive use of fine jeweler's instruments, which also may be seen with the use of cherry-pitting tools
Weight lifter's callus 6 Callosities over the palmar metacarpophalangeal jointsCaused by the friction of weight-lifting apparatus (This also may be seen in athletes who participate in crew.)
Prayer callus 78 Callosity on the foreheadFrom kneeling prayer with the hands on the forehead
Cigarette lighter's thumb 9 Hyperkeratosis of the radial aspect of the thumbCaused by excessive cigarette lighter flicking
Knuckle pads 10 Hyperkeratosis over the knucklesCaused by boxing training
Russell sign 11 Callosities of the dorsum of the hand over the metacarpophalangeal and interphalangeal jointsCaused by the friction involved with self-induced emesis in bulimia nervosa
Screwdriver operator's clavus 12 Palmar surface of the handOccurs at the site of contact with a screwdriver handle
Spine bumpsHyperkeratosis over the spinal columnCaused by dancing with spinning on one's back
Hairdresser's handFirst finger on dominant handCallus formation at the site of friction caused by scissors around the first finger on the dominant hand
Sucking calluses 13 Lip, hand, or foot of a newbornCallus formation at the site of an area of suction on the lip, hand, or foot of a newborn
Vamp disease 14 FeetClavus formation due to wearing tight high-heeled shoes


Screwdriver operator's callus (ie, clavus).

Screwdriver operator's callus (ie, clavus).

Screwdriver operator's callus (ie, clavus).

Screwdriver operator's callus (ie, clavus).

Pathophysiology

The shape of the hands and feet are important in clavus formation. Specifically, the bony prominences of the metacarpophalangeal and metatarsophalangeal joints often are shaped in such a way as to induce overlying skin friction. As clavus formation ensues, friction against the footwear is likely to perpetuate hyperkeratosis. Toe deformity, including contractures and claw, hammer, and mallet-shaped toes, may contribute to pathogenesis. Bunionettes, ie, callosities over the lateral fifth metatarsal head, may be associated neuritic symptoms due to compression of the underlying lateral digital nerves. Furthermore, Morton toe, in which the second toe is longer than the first toe, occurs in 25% of the population; this may be one of the most important pathogenic factors in a callus of the common second metatarsal head, ie, an intractable plantar keratosis. Chronic or repetitive motion may also induce clavus formation, as is seen in computer users (ie, "mousing" callus).15

Frequency

United States

The clavus is a common disorder because of the frequency of usage of occlusive footwear and participation in repetitive activities, such as running.

Mortality/Morbidity

Extensive thickening of the skin may result in chronic pain, particularly in the forefoot; in certain situations, ulcer formation may result. Clavus may be a sign of underlying neuropathy due to diabetes or neuroborreliosis, or due to the deformities of rheumatoid arthritis. In the case of neuropathy, a clavus may hide ulceration or denote abnormal neurovasculature of the feet. In the case of rheumatoid arthritis, clavus may enhance the pain of deformed joints.

Race

Any race may be affected.

Sex

Clavus is more common in women than in men because of their use of occlusive and poorly fitted footwear.

Age

Anyone can have a clavus, but most individuals acquire the risk factors for clavus formation after puberty because of the onset of traumatic footwear use, repetitive motion injuries, and progressive foot deformities.

Clinical

History

A clavus forms because of inappropriate distribution of pressure onto a specific site, usually of the foot. A localized callosity of the soles, which do not resolve, are termed plantar callus, heloma, tyloma, keratoma, or plantar corn. When callosities occur over one or more lateral metatarsals, they are termed intractable plantar keratoses.

Physical

Clinically, all these lesions look like hyperkeratotic or thick skin; maceration and secondary fungal or bacterial infections are a common overlying feature in heloma molle and diabetes. Plantar helomas tend to have a central keratin plug, which, when pared, reveal a clear, firm, central core. The most common sites for clavus formation are the feet, specifically the dorsolateral aspect of the fifth toe for heloma durum, in the fourth interdigital web of the foot for heloma molle, and under the metatarsal heads for calluses.

  • Examination of patients should include assessment of the types of footwear worn, activities performed, gait, and current home therapy or previously prescribed therapy.
  • Lesions should be palpated and pared to look for underlying blood vessels (black dots or pinpoint bleeding), which are seen in warts, and to look for underlying ulcerations, as seen in neurovascular ulcerations (especially in patients with diabetes).
  • Paring of callosities or corns, as opposed to plantar warts, should reveal normal dermatoglyphics.16
  • Callosities are generally more painful with direct pressure, whereas warts are more painful with lateral pressure.17
  • Pedobarographic studies are pressure assessments that may be used to detect an altered distribution of foot pressure. MRI may delineate diabetic foot problems more clearly.
  • Biopsy of lesions reveals hyperkeratosis and, occasionally, mucin deposition.

Causes

  • Conditions associated with clavus formation include the following:
  • Faulty mechanics: Irregular distribution of pressure and repetitive motion injury (especially in athletes) are believed to be the main inciting causes; however, inappropriately shaped or constrictive footwear in the presence of bony prominences (eg, talar bone prominences24 ) may exacerbate clavus formation. Furthermore, some disorders may alter the shape or sensation of the soles of the feet. Bony prominences and faulty foot mechanics then allow clavus formation to continue.25,26,27,28,29
  • Rheumatoid arthritis: About 17% of patients with rheumatoid arthritis present with intractable foot pain. Chronic arthritis leads to foot deformities and consequent callus formation. Bleeding into callosities in patients with rheumatoid arthritis may be a sign of rheumatoid angiitis.
  • Diabetes mellitus: In patients with diabetes, chronic callosities in the presence of neurovascular deterioration may lead to ulcerations and superinfections.
  • Obsessive-compulsive disorder (pseudo-knuckle pads)
  • Ectopic nail

More on Clavus

Overview: Clavus
Differential Diagnoses & Workup: Clavus
Treatment & Medication: Clavus
Follow-up: Clavus
Multimedia: Clavus
References
Further Reading

References

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

  2. Mann RA. Pain in the foot. 1. Evaluation of foot pain and identification of associated problems. Postgrad Med. Jul 1987;82(1):154-7, 160-2. [Medline].

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

  4. Viegas SF, Torres FG. Cherry pitter's thumb. Case report and review of the literature. Orthop Rev. Mar 1989;18(3):336-8. [Medline].

  5. Villano PA, Ruocco V, Pisani M. The cameo engraver's corn. Int J Dermatol. Jul-Aug 1990;29(6):424-5. [Medline].

  6. Scott MJ Jr, Scott NI, Scott LM. Dermatologic stigmata in sports: weightlifting. Cutis. Aug 1992;50(2):141-5. [Medline].

  7. Mishriki YY. Skin commotion from repetitive devotion. Prayer callus. Postgrad Med. Mar 1999;105(3):153-4. [Medline].

  8. O'Goshi KI, Aoyama H, Tagami H. Mucin deposition in a prayer nodule on the forehead. Dermatology. 1998;196(3):364. [Medline].

  9. Maharaj D, Naraynsingh V. Cigarette lighter thumb. Am J Med. Apr 15 2001;110(6):506. [Medline].

  10. Kanerva L. Knuckle pads from boxing. Eur J Dermatol. Jul-Aug 1998;8(5):359-61. [Medline].

  11. Daluiski A, Rahbar B, Meals RA. Russell's sign. Subtle hand changes in patients with bulimia nervosa. Clin Orthop Relat Res. Oct 1997;(343):107-9. [Medline].

  12. Koh D, Jeyaratnam J, Aw TC. An occupational mark of screwdriver operators. Contact Dermatitis. Jan 1995;32(1):46. [Medline].

  13. Heyl T, Raubenheimer EJ. Sucking pads (sucking calluses) of the lips in neonates: a manifestation of transient leukoedema. Pediatr Dermatol. Aug 1987;4(2):123-8. [Medline].

  14. Gibbs RC. "Vamp disease". J Dermatol Surg Oncol. Feb 1979;5(2):92-3. [Medline].

  15. Goksugur N, Cakici H. A new computer-associated occupational skin disorder: Mousing callus. J Am Acad Dermatol. Aug 2006;55(2):358-9. [Medline].

  16. Bae JM, Kang H, Kim HO, Park YM. Differential diagnosis of plantar wart from corn, callus and healed wart with the aid of dermoscopy. Br J Dermatol. Jan 2009;160(1):220-2. [Medline].

  17. Kurvin L, Volkering C. [Diagnosis and treatment of warts, corns, and clavi]. MMW Fortschr Med. Mar 8 2007;149(10):31-3. [Medline].

  18. Murray HJ, Young MJ, Hollis S, Boulton AJ. The association between callus formation, high pressures and neuropathy in diabetic foot ulceration. Diabet Med. Nov 1996;13(11):979-82. [Medline].

  19. Manalo FB, Marks A, Davis HL Jr. Doxorubicin toxicity. Onycholysis, plantar callus formation, and epidermolysis. JAMA. Jul 7 1975;233(1):56-7. [Medline].

  20. Oriba HA, Lo JS, Bergfeld WF. Callused feet, thick nails, and white tongue. Pachyonychia congenita. Arch Dermatol. Jan 1991;127(1):113-4, 116-7. [Medline].

  21. Lemont H, Ravick A. Hemorrhage within plantar callus. A cutaneous sign of rheumatoid angiitis. J Am Podiatry Assoc. Jan 1980;70(1):22-5. [Medline].

  22. Wollina U, Mohr F, Schier F. Unilateral hyperhidrosis, callosities, and nail dystrophy in a boy with tethered spinal cord syndrome. Pediatr Dermatol. Nov-Dec 1998;15(6):486-7. [Medline].

  23. Robbins JM, Ballew KK, Lowery CR, Husni EA. Asymptomatic occlusive arterial disease. A case report. J Am Podiatr Med Assoc. Nov 1985;75(11):616-8. [Medline].

  24. Verbov JL, Monk CJ. Talar callosity--a little-recognized common entity. Clin Exp Dermatol. Mar 1991;16(2):118-20. [Medline].

  25. Oztekin HH, Boya H, Nalcakan M, Ozcan O. Second-toe length and forefoot disorders in ballet and folk dancers. J Am Podiatr Med Assoc. Sep-Oct 2007;97(5):385-8. [Medline].

  26. Baccouche D, Mokni M, Ben Abdelaziz A, Ben Osman-Dhahri A. [Dermatological problems of musicians: a prospective study in musical students]. Ann Dermatol Venereol. May 2007;134(5 Pt 1):445-9. [Medline].

  27. Gambichler T, Uzun A, Boms S, Altmeyer P, Altenmüller E. Skin conditions in instrumental musicians: a self-reported survey. Contact Dermatitis. Apr 2008;58(4):217-22. [Medline].

  28. Verma SB, Wollina U. Callosities of cross legged sitting: "yoga sign"--an under-recognized cultural cutaneous presentation. Int J Dermatol. Nov 2008;47(11):1212-4. [Medline].

  29. Darvall WA. Flash dancing and spine bumps. Med J Aust. Apr 28 1984;140(9):568. [Medline].

  30. Dainichi T, Honma Y, Hashimoto T, Furue M. Clavus detected incidentally by positron emission tomography with computed tomography. J Dermatol. Apr 2008;35(4):242-3. [Medline].

  31. Thomas JR 3rd, Doyle JA. The therapeutic uses of topical vitamin A acid. J Am Acad Dermatol. May 1981;4(5):505-13. [Medline].

  32. 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].

  33. George WM. Linear lymphatic hypopigmentation after intralesional corticosteroid injection: report of two cases. Cutis. Jul 1999;64(1):61-4. [Medline].

  34. McDowell BA. Carbon dioxide laser excision of benign pedal lesions. Clin Podiatr Med Surg. Jul 1992;9(3):617-32. [Medline].

  35. 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].

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

  37. Kitaoka HB, Patzer GL. Chevron osteotomy of lesser metatarsals for intractable plantar callosities. J Bone Joint Surg Br. May 1998;80(3):516-8. [Medline].

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

Further Reading

Clinical guidelines

Dermatologic manifestations.
New York State Department of Health - State/Local Government Agency [U.S.].  2004. 15 pages.  NGC:003931

Guidelines for the management of actinic keratoses.
British Association of Dermatologists - Medical Specialty Society.  2007 Feb.  9 pages. NGC:005656


Clinical trials


Potential Research Study Participant Registry

Study to Compare Different Light Therapies (Narrowband Ultraviolet B Vs PUVA) for Hand and Foot Skin Diseases.


Related eMedicine topics


Corns (Dermatology)

Arsenical Keratosis

Warts, Nongenital Warts, Plantar

Keywords

callosity, corn, heloma, heloma durum, heloma molle, callous, callus, plantar callus, heloma, tyloma, keratoma, plantar corn, plantar callus, intractable plantar keratoses, jeweler's callus, cherry pitter's thumb, cameo engraver's corn, weight lifter's callus, prayer callus, cigarette lighter thumb, knuckle pads, Russell's sign, Russell sign, screwdriver operator's clavus, spine bumps, hairdresser's hand, sucking callus, Vamp disease, mousing callus

Contributor Information and Disclosures

Author

Nanette Silverberg, MD, Assistant Clinical Professor, Department of Dermatology, Columbia University School of Medicine; Director of Pediatric Dermatology, Department of Dermatology, St Luke's Roosevelt Hospital Center, Maimonides Medical Center and Beth Israel Medical Center
Nanette Silverberg, MD is a member of the following medical societies: American Academy of Dermatology, American Academy of Pediatrics, American Association of University Women, American Medical Association, American Medical Women's Association, Dermatology Foundation, International Society of Pediatric Dermatology, Phi Beta Kappa, Sigma Xi, Society for Pediatric Dermatology, and Women's Dermatologic Society
Disclosure: Nothing to disclose.

Medical Editor

Smeena Khan, MD, Private Practice, Adult and Pediatric Dermatology Associates
Smeena Khan, MD is a member of the following medical societies: Alpha Omega Alpha and American Academy of 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 J Miller, MD, Associate Professor of Dermatology, Penn State University College of Medicine; Staff Dermatologist, Penn State Milton S Hershey Medical Center
Jeffrey J Miller, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Dermatology, Association of Professors of Dermatology, North American Hair Research Society, and Society for Investigative Dermatology
Disclosure: Nothing to disclose.

CME Editor

Glen H Crawford, MD, Assistant Clinical Professor, Department of Dermatology, University of Pennsylvania School of Medicine; Chief, Division of Dermatology, The Pennsylvania Hospital
Glen H Crawford, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Dermatology, American Medical Association, Phi Beta Kappa, and Society of USAF Flight Surgeons
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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