Medical Care
The use of orthotics and conservative footwear with extra toe space are often beneficial. When all else fails, surgery may be performed.
If abnormal dermatoglyphics or pinpoint bleeding is seen, wart therapy is initiated. If normal dermatoglyphics are noted, salicylic acid compounds and orthotics may be beneficial. Relief of symptoms may be achieved by thinning and cushioning of the involved lesions.
Paring of the lesions immediately relieves pain, especially with helomas. Lesions may be maintained in this state if the patient uses short soaks and pumice stone debridement at home. Debridement may be enhanced with the use of keratolytic agents, such as ureas, alpha-hydroxy acid (eg, glycolic, malic, or lactic acid), or beta-hydroxy acid (eg, salicylic acid). [55] Garlic extracts have also been described as being helpful. [56]
Self-adhesive pads are most effective for reducing thick lesions, whereas lotions, creams, and medicaments in petrolatum are best for maintenance. Most salicylic acid compounds are 10-17%. High concentrations of salicylic acid (eg, 40%) may lead to severe maceration, and in patients with diabetes, it may lead to frank foot ulcerations. [57] Intralesional triamcinolone and topical vitamin A acid compounds also may reduce localized hyperkeratosis. Triamcinolone can lead to localized hypopigmentation. [58]
A statistically significant reduction in pain at 6 months with complete and partial resolution rates of 26% and 50%, respectively, were seen with electrosurgery compared with resolution rates of 4% and 28%, respectively, with sharp debridement in one study. [59]
Soft corns are often difficult to treat because they develop from underlying pressures in between the fourth and fifth digit, caused by bony prominences. [5] Soft corns are best treated with properly fitting footwear and better foot hygiene in order to decrease the likelihood for infection. Applying an antifungal or antibacterial powder after washing the area and using lamb’s wool or a toe spacer are additional techniques used to treat soft corns. [12] A good option in patients with coexisting dermatophytosis complex is 20% aluminum chloride hexahydrate solution (Drysol).
Reduced friction may be accomplished with the use of silicone-lined sleeves on the toes, padding, and, in select cases, silicone [60] or collagen injections [6] over the bony prominence in question.
Lamb's wool may be beneficial in interdigital corns. Pads or permanent insoles, which place pressure proximal to the metatarsal head, relieve stress on the region. Insoles may be made of silicone or soft plastics.
Shoes with extra length are required for toe deformity, and shoes with extra width are required for lateral toe callosities. Shoes should be soft inside without seams that rub or press. Orthotics can be placed in the shoe for patients with abnormalities of the foot, such as cavovarus. Orthotics can be created by using insoles made to correct deformities noted on dynamic pressure molds. Reduction of heel height may be helpful for patients with metacarpal head callosities. [61]
Vacuum orthoses have been described to aid in lesional clearance for diabetic patients with plantar callosities. [62]
Following are additional treatment modalities:
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Filler injections: A retrospective evaluation of the use of fluid silicone in treating loss of plantar fat reveals a unique treatment option for corns and calluses. [60, 65, 66] Balkin reports he treated more than 1500 patients from 1964-2005 with silicone injections to digital and plantar sites. He found that 60-80% experienced some form of pain relief and elimination of calluses. Booster treatments are often needed, and the only complication reported was skin discoloration. [66] Injection of 0.1 mL of medical-grade liquid silicone below a clavus and above the bone has been reported to have good results, [67] but it is not presently approved by the US Food and Drug Administration. [61] Whether other filler substances can achieve the same success is unknown; a case report suggests hyaluronic acid gel injections may be beneficial. [68]
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Laser: A carbon dioxide laser can be used to pare deep lesions. [69]
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Combination products: A combination product to be applied by physicians consisting of 1% cantharidin, a vesicant, mixed with 30% salicylic acid and 5% podophyllin has been described as effective for most people after just one session. In a study looking at 72 patients, 90.3% with callosities on the feet demonstrated that application of this agent after paring with a No. 15 blade effected clearance in 79.2%, 12.5%, 6.9%, and 1.4% after 1, 2, 3, and 4 sessions, respectively, with only one recurrence at 1 year follow-up. [70]
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Botulinum toxin: Injection of botulinum toxin into the plantar area of two patients with pachyonychia congenita has been described as beneficial for the reduction of clavus formation and blisters. [71]
Overall, removing or adjusting the mechanical stress causing the corn—finding footwear that matches the length and width of a foot—is the first step towards treatment of this condition. [6, 72] Patient awareness of his or her footwear is critical to the prevention of future corns. Conservative treatment can be continued at home and may consist of using a pumice stone for minor debridement, practicing good foot hygiene, and using soft spacers or a silicone sleeve, which can be bought at most retail stores. [5, 63]
Further inpatient care
Further inpatient care usually is not required unless surgical adjustments are needed.
A patient with diabetes who has neuropathic ulcers and overlying clavus formation may require further care.
Rheumatoid arthritis patients may benefit more from surgical interventions than callous debridement. Forefoot arthroplasty and first metatarsophalangeal joint implants may improve clavus formation and rheumatoid foot pain over the long term.
Measurement of the foot for orthoses is beneficial in the case of multiple clavi.
Surgical Care
Surgery to remove the bony prominences is indicated only if all conservative measures fail. [6, 7, 33] Surgical procedures include bunionectomy, syndactylization, osteotomy, and arthroplasty. [5, 33] Long-term improvement for lateral fifth-toe corns and interdigital corns has been achieved with partial and complete condylectomy. [33]
Chronic foot pain despite conservative therapy is the number one indication for surgery.
Hallux valgus correction may aid in reduction of painful callosities over the long term. [62]
Surgical corrections for claw, hammer, and mallet toes are simple procedures.
Shaving of prominent condyles of bony prominences may be beneficial, particularly on the fifth digit.
Arthroplasty of the fifth toe interphalangeal joint also may be performed.
Metatarsal condylectomy or chevron osteotomy may be performed to relieve metatarsal head pressure. [73]
Mann and DuVries described the use of a combination of arthroplasty and condylectomy. This combination results in 95% clearance, with only a 13% occurrence of transfer lesions. [74]
When thinning of the plantar fat pads is contributory to the formations of callosities, injectable silicone can be used on the soles underneath the callosities and corns to reduce pressure-related callous formation.
Description of excision followed by either grafting, use of flaps, or grafting using split-thickness graft with or without a collagen/elastin matrix graft has been described as effective in a single resistant case. [74]
Consultations
If patients do not respond to conservative treatment, further evaluation by a podiatrist or orthopedic surgeon is recommended. Extensive orthoses are available to help remove mechanical stresses on the foot, and an orthopedist or podiatrist should be consulted.
An orthopedist and a podiatrist also can be helpful in adjusting abnormalities of gait or pressure distribution.
In cases of suspected arthritis, a rheumatologist can be consulted.
Dermatologists are best consulted to assess for the possibility of other disorders in the differential diagnosis, especially warts and keratoderma.
Diet
Weight loss may reduce pain from corns and improve biomechanics in patients who are obese.
Activity
Patients are advised to reduce or eliminate certain mechanical forces or motions. However, certain activities, particularly work related, may be unavoidable or patients may be reluctant to make the necessary changes.
Adjustment of the footwear and the use of special insoles aid in the maintenance of full mobility and eliminate the need for activity limitation.
Prevention
Deterrence and prevention includes the use of corn pads, web spacers, and properly fitting shoes (see Pathophysiology and Medical Care). Patients can treat their corns at home using a pumice stone to regularly debulk the lesion after a shower, when the skin is soft.
Long-Term Monitoring
Follow-up care is important to ensure control of the hyperkeratosis because patients may require regular, repeated applications of keratolytic agents in conjunction with careful paring.
Patients with special health concerns, including diabetic patients, amputees, and elderly persons, may require more frequent follow-up visits in order to decrease the likelihood of a more catastrophic complication, particularly secondary bacterial infection, from the initial lesion.
Numerous contributory factors may result in thickened skin on the feet. Factors such as occupation, athletic pursuits, footwear, underlying bony abnormalities, and problems with general health may contribute to clavus formation.
Etiologic factors must be carefully assessed before treatment can be given.
Symptomatic relief can be achieved by thinning the hyperkeratotic lesions and by using cushions or insoles, which reduce pressure on the affected areas.
Surgery can be an adjunctive treatment in those patients with intractable clavus formation and chronic foot pain.
Using a combination of modalities and reducing the pressure of footwear ultimately reduces the appearance and discomfort of the clavus.
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Hard corn on the lateral surface of fifth toe. Courtesy of James K. DeOrio, MD.
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Hard corn over the proximal interphalangeal joint of second toe. Courtesy of James K. DeOrio, MD.
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Calluses on the palmar surface of the hands of a body builder. Courtesy of James K. DeOrio, MD.
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Screwdriver operator's callus (ie, clavus).
Tables
Vernacular Term |
Location |
Association |
Jeweler's callus, cherry pitter's thumb, [16] cameo engraver's corn [17] |
Thumb |
Digital 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 [18] |
Callosities over the palmar metacarpophalangeal joints |
Caused by the friction of weight-lifting apparatus (This also may be seen in athletes who participate in crew.) |
Callosity on the forehead |
From kneeling prayer with the hands on the forehead |
|
Cigarette lighter's thumb [21] |
Hyperkeratosis of the radial aspect of the thumb |
Caused by excessive cigarette lighter flicking |
Knuckle pads [22] |
Hyperkeratosis over the knuckles |
Caused by boxing training |
Russell sign [23] |
Callosities of the dorsum of the hand over the metacarpophalangeal and interphalangeal joints |
Caused by the friction involved with self-induced emesis in bulimia nervosa |
Screwdriver operator's clavus [24] |
Palmar surface of the hand |
Occurs at the site of contact with a screwdriver handle |
Spine bumps |
Hyperkeratosis over the spinal column |
Caused by dancing with spinning on one's back |
Hairdresser's hand |
First finger on dominant hand |
Callus formation at the site of friction caused by scissors around the first finger on the dominant hand |
Sucking calluses [25] |
Lip, hand, or foot of a newborn |
Callus formation at the site of an area of suction on the lip, hand, or foot of a newborn |
Vamp disease [26] |
Feet |
Clavus formation due to wearing tight high-heeled shoes |
Muay Thai kickboxers [27] |
Feet |
Callosities on the forefoot (77.5%), on the plantar first metatarsal (55.3%), and on the big toe (33.3%) |
