WARTS, PLANTAR

WARTS, PLANTAR - Gary J.Silko, MD, MS
BASICS
DESCRIPTION
• Discrete or grouped firm keratotic masses on the sole of the foot initiated by a viral infection of keratinocytes
• System(s) Affected: Skin/Exocrine
• Synonym(s): Verruca plantaris
ALERT
Pediatric Considerations
Duration of warts is generally shorter in children than in adults.
Pregnancy Considerations
Avoid bleomycin treatments.
GENERAL PREVENTION
Use rubber footwear in communal shower areas.
EPIDEMIOLOGY
• Predominant age: Any age, although more common in children and young adults
• Predominant sex: Female > Male (slightly)
Incidence
In the US: Widespread; 2,000/100,000
RISK FACTORS
• AIDS
• Atopic dermatitis
• Lymphomas
• Patient taking immunosuppressive drugs
Genetics
Unknown
ETIOLOGY
Human papillomavirus type 1; less commonly types 2, 4, 27, and 57

DIAGNOSIS
TESTS
• Foot pain
• Discrete or grouped masses on sole of foot with disruption of normal skin markings
• Generally occur at pressure points
• Rough, hyperkeratotic surface with brown-black dots (thrombosed capillaries)
• Callus formation
• Leg or back pain (distortion of posture)
Diagnostic Procedures/Surgery
• Inspection usually confirms the diagnosis.
• If cannot distinguish between callus and wart, can examine with a magnifying lens. The wart should demonstrate a highly organized mosaic pattern.
• When pared down, have a soft central core and bleeding points (unlike calluses)
Pathological Findings
Acanthotic epidermis with hyperkeratosis, papillomatosis, and parakeratosis
DIFFERENTIAL DIAGNOSIS
• Corns (clavi)
• Calluses
• Black heel (ruptured capillaries)
TREATMENT
STABILIZATION
• Outpatient cryotherapy at weekly intervals
• Repeated parings at weekly intervals with or without use of a keratolytic is also an option. Most successful appears to be curettage and chemical cautery (with phenol or trichloroacetic acid) or light electrocautery. (Note: Extreme care must be exercised with this procedure, because excessive cautery or curettage can cause a painful scar.)
GENERAL MEASURES
• If warts are asymptomatic, no treatment is necessary. However, patient may be at risk for spread of warts.
• Warm soaks followed by patient's paring of the top layer of skin on repeated occasions may speed disappearance.
• Patient may use pumice stone, emery board. or a blade.
• OTC keratolytics containing salicylic acid in liquid or film may help. The advised procedure is paring of skin followed by warm soaks, and finally application of a few drops of keratolytic daily.
• Hyperthermia: Hot water immersion (113F) 1/2-3/4 hour 2-3 times per week for 16 treatments is effective for some patients.
• Duct tape: Cut a piece to the size of the wart and apply continuously for 6 days, remove and repeat for up to 2 months. (5)[B]
• Other measures include use of a heel bar or appropriate padding to relieve pressure points where warts tend to aggregate. (1)[C]
Diet
No special diet
Activity
Ambulatory unless warts or treatment are painful
MEDICATION (DRUGS)
First Line
• No effective antiviral wart medications currently exist. Keratolytics (OTC or prescription) and a variety of chemotherapeutic acids may be used.
• Salicylic acid: See "General Measures" for instructions.
• 40% salicylic acid plasters: available as Mediplast. It is supplied in 3  4 in sheets which are cut to the size of the wart, and the sticky surface is applied to the wart. They are removed every 1-2 days, the white keratin peeled, and a fresh plaster applied.
• Chemotherapy dichloroacetic acid and trichloroacetic acid kits are available. Callus is pared and the surrounding skin is protected by a ring of petrolatum. The wart(s) are coated with acid, which is then worked into the wart with a sharp toothpick. Procedure should be repeated at weekly intervals.
• Transdermal salicylates (Trans-Plantar)
• Vesicants containing cantharidin (Cantharone, Verrusol), applied in the office, allowed to dry, and are then covered with occlusive tape for 24 hours.
• Contraindications: Infection, vascular insufficiency
• Precautions
- If the dermis is damaged with any of the above procedures, a scar may result which can be permanently painful.
- Care should be taken to avoid excessive contact with normal skin when using keratolytics or chemotherapy.
- Avoid bleomycin treatment during pregnancy.
- Imiquimod has not been studied in patients 18 years. (1)[C]
Second Line
• Bleomycin injected intralesionally every 2 weeks
• Imiquimod (Aldara) 5% cream applied daily after soaking. It appears to be more effective when occluded and when in combination with other treatments such as cryotherapy or keratolytics.
• Alternative procedures include laser therapies (various).
SURGERY
• Cryotherapy: Application of liquid nitrogen is often effective. It usually requires at least four applications at weekly or biweekly intervals. Aggressive cryotherapy may cause blistering or even scarring, so light applications with 2 freeze-thaw cycles is preferred.
• Blunt dissection: A simple surgical procedure is effective and usually nonscarring. It requires inserting a blunt dissector between the wart and normal skin and separating the wart using short, firm stroke.
• Carbon dioxide laser surgery: used for recalcitrant warts (1)[C]
FOLLOW-UP
PROGNOSIS
The course of plantar warts is like that of other varieties of warts (i.e., highly variable). Most resolve spontaneously in weeks to months.
COMPLICATIONS
• Scarring with overly aggressive treatment
• A rare type of verrucous carcinoma, epithelioma cuniculatum, is thought to arise from these warts.
PATIENT MONITORING
With any treatment modality, follow-up weekly.
REFERENCES
1. Habif TP. Clinical Dermatology. 4th ed. New York, NY: Mosby; 2004: 374-377.
2. Epstein E. Common Skin Disorders. 5th ed. Philadelphia, PA: WB Saunders; 2001.
3. Freedberg IM et al. Fitzpatrick's Dermatology in General Medicine, 6th ed. New York, NY: McGraw-Hill; 2003;2120-2123, 2129.
4. James WD, Berger TG, Elston DM. Andrews' Diseases of the Skin, 10th ed. Philadephia, PA: WB Saunders; 2006;405-407.
5. Focht DR, Spicer C, Fairchok MP. The efficacy of duct tape vs cryotherapy in the treatment of verruca vulgaris. Arch Pedatr Adolesc Med. 2002;156:971-974.
MISCELLANEOUS
See also: Condyloma Acuminata; Warts