II. Epidemiology
- More common in children, adolescents and young adults
- Plantar Warts responsible for a third of warts
- Affects up to 20% of children ages 4 to 12 years old
III. Pathophysiology
- Human Papillomavirus types 1,2 and 4 most common
IV. Predisposing factors
- Excessive sweating
- Repetitive microtrauma to foot (e.g. sports)
- Public showers
V. Types
- Classic Plantar Wart
- Mosaic Wart (coalescence of multiple lesions)
- Myrmecia (refers to anthill-like lesion)
- Epidermal lesion extends deeply under skin surface
- Usually associated with HPV Type 1
VI. Symptoms
- Pain at heel and Metatarsal heads (pressure points)
- Worse with walking (feels like pebble in shoe)
VII. Signs
- Location
- Pressure points on Metatarsal heads or heel
- Characteristics
- Accentuated by
- Soak in warm water 15-20 minutes to make more visible
VIII. Differential diagnosis
- Corn (or callus)
- Yellow-white firm glistening central kernel (pared)
- Painless on lateral pressure
- Retain normal fingerprint lines (warts do not)
- Contrast with pinpoint blood vessels of Plantar Warts
- Stress Fracture
- Foreign body reaction
- Lichen Planus
- Black Dot Heel (sheering Trauma in Sports)
- Epithioma cuniculatum (verrucous carcinoma)
IX. Precautions
- No treatment needed if asymptomatic
- Avoid aggressive technique
- Electrodessication and Curettage
- Surgical excision
- CO2 Laser
X. Management
-
General
- Topical treatments require 2-3 months for eradication
- Relieve pressure on wart area with pads
- Soak foot before application of salicylic acid
-
Salicylic Acid Plasters 40% (Mediplast)
- Effective over the course of months
- Salicylic Acid 17% in flexible collodion (Occlusal)
- Does not slip like plasters
- As effective as Cryotherapy
- See also Keratolytic Agents
- Canthacur PS (SEE Cantharidin)
- Use after soaking feet in hot water 10-15 minutes
- Occlude with tape
- Remove after 48 hours
-
Intralesional Bleomycin
- Performed by dermatology in refractory cases
- Contraindicated in pregnancy
-
Cryotherapy
- Use caution on weight bearing plantar surfaces
- Risk of painful scarring
- For Plantar Warts, Cryotherapy was no more effective than home therapy with pumice stone and salicylic acid
XI. Management: Blunt surgical dissection
- Precautions
- Careful! Risk of painful scarring if too deep
- Do not enter Dermis on dissection
- More effective than electrosurgical techniques (ED&C)
- Careful! Risk of painful scarring if too deep
- Efficacy: 90% cure rate
- Technique
- See Blunt Dissection
- After lesion removed consider Keratolytic agent
- Cover normal skin with Vaseline (petroleum jelly)
- Apply 88% Trichloroacetic acid
- References
XII. Course
- Two thirds of Plantar Warts resolve by 2 years without treatment
- Recurrence after treatment is common