Lecture 4 - Common Foot Disorders Flashcards
Is the rate of mitotic division in basal cell layer normally more or less than the rate of surface cellular desquamation?
Normally equal
What occurs during corn or callus development?
Friction and pressure increase mitotic activity of the basal cell layer, leading to the migration of maturing cells through prickle cell and granular cell layers => hyperkeratosis
What are factors that contribute to corns and calluses?
- Friction due to loose or tight fitting shoes
- Structural biochemical problems
- Not wearing socks w/ shoes or wearing ill fitting socks
- Walking barefoot
- Weight gain
- Secondary condition to plantar warts
What is a corn?
- Small raised, sharply demarcated, hyperkeratotic lesion
- Hard corns have central core that is triangular shaped and points inward
What are the 3 types of corns?
- Soft (heloma molle)
- Hard (heloma durum)
- Plantar
What are the signs and symptoms of a hard corn?
- Well defined
- Yellowish-gray colour
- Few mm - 1 cm or more in diameter
- Shiny, dry, and polished
- Central core visible
- Pain
- Affects skin directly overlying bony prominence or may occur on soles of feet
- Usually occurs on surface of 4th or 5th toes
What are the signs and symptoms of a soft corn?
- Whitish thickenings of skin
- Soft appearance
- Usually found on webs btwn 4th and 5th toes
- May be painful
- Often confused w/ Athlete’s foot
What is a plantar corn?
Corn on the plantar surface of the foot that causes pain upon walking
What is a plantar corn often confused with?
Plantar wart
What is a callus?
- Superficial patches of hornified epidermis
- No central core
What are the signs and symptoms of a callus?
- Yellowish-white
- Normal skin pattern; no central core
- Borders not well defined
- Few mm to several cm in diameter
- Slightly elevated
- Found on areas where the upper layers of skin are naturally thick (soles of feet, heel/ball of foot)
What is the pathophysiology of plantar warts?
- HPV is transmitted via person-to-person contact, autoinoculation, or via contaminated surfaces
- HPV enters skin through small cut or abrasion
- HPV infects upper epidermis and causes squamous epithelial cells to proliferate
- HPV can remain latent or cause subclinical infection
What is a plantar wart?
- Common viral infection of skin and mucous membrane
- Benign tumours caused by human papilloma virus
- Incubation period btwn initial infection to warty lesion varies btwn 1-8 months
Are warts permanent?
No
Why are warts important to treat?
- Can spread
- Unsightly
- Can be painful and restrict activities
- Potential to transform into malignant lesions
What are the signs and symptoms of plantar warts?
- Can occur on sole of foot, sole of heel, great toe, head of metatarsal bone and ball
- Circular lesion w/ wart in center
- 0.5-3 cm diameter
- Surface is rough, grayish-brown and friable surrounded by skin that is thick and heaped
- Normal pattern of skin is interrupted
- Thrombosed capillaries appear as black dots in center of lesion or as pin point bleeding sometimes described as “seeds”
- Usually painless unless direct pressure applied
What is the differential diagnosis of a hard corn?
- Callus
- Plantar wart
What is the differential diagnosis of a soft corn?
Tinea pedis (athlete’s foot)
What is the differential diagnosis of a callus?
- Corn
- Plantar wart
What is the differential diagnosis of a wart?
- Callus
- Corn
- Squamous cell carcinoma
What is the assessment for patients w/ corns, calluses, and bunions?
- When possible, inspect the patient’s feet and footwear
- Note the presence of lesions, changes in skin colour, sensation, texture or temperature, swelling, pain, rashes, or obvious abnormalities in foot structure
- Check the fit of the shoe, paying special attention to its length and the width and depth of the toe box
What are the goals of therapy for corns and calluses?
- Remove corns and calluses
- Avoid and prevent/minimize complications
- Prevent recurrence
What is the pharmacological treatment of corns and calluses?
- Salicylic acid = 1st line pharmacological treatment
- For self-treatment - plaster vehicle 12-40% or collodion-like vehicle 12-17.6%
Salicylic acid is a _______ agent
Keratolytic
What are the advantages to an SA collodion?
- Forms film which prevents moisture loss
- Usually easiest to apply for patient
- Less likely to run onto other areas of skin
What are the advantages to an SA plaster?
- Provides direct and prolonged contact w/ skin
- May be cut to fit size of lesion
- Disks or pads more convenient
- Easy to apply
What are the disadvantages to an SA collodion?
- Takes longer to resolve
- Flammable and volatile
- Occlusive nature allows systemic absorption of drug
- More irritating than other formulations
What is a disadvantage to an SA plaster?
Patient may be sensitive to adhesive
What is the indication for an SA collodion?
More useful in the treatment of soft corns, rather than calluses
What is the indication for an SA plaster?
Hard corns and calluses
What is the duration of treatment for an SA collodion?
- Hard corns and calluses - up to 14 days
- Soft corn - 3-6 days
What is the duration of treatment for an SA plaster?
Max of 5 treatments over a 2 week period (1 treatment = max of 48 hours)
What are the directions of use for an SA liquid/collodion?
- Soak foot for 5 minutes, dry foot and apply 1-2 times/day
- Apply 1 drop at a time until area is well covered
- Allow drops to dry and harden
- Do not let adjacent areas of skin come in contact w/ drug
- Periodically soak foot in warm water and remove macerated skin
What are the directions of use for an SA plaster/disk/pad?
- Soak foot for 5 minutes, dry and apply every 48h
- If using plaster, trim plaster to follow contours of lesion
- Apply and cover w/ adhesive tape
- If using disk/pads, apply appropriately sized on area and cover
- Remove w/in 48 hrs
- Soak in warm water and remove macerated skin
What are some non-pharms for corns and calluses?
- Eliminate cause of condition
- Soak affected area daily throughout treatment for 10 mins in warm water and gently remove dead tissue (pummice stone on wet foot or emery board on dried foot)
- A foam or cushioned pad w/ an opening can be used up to 1 week to relieve pressure
- Change cushion every day
- Keep feet clean and dry
- Avoid moisturizers between toes
- Check feet daily
How can you prevent corns and calluses?
- Maintain moisture balance
- Remove dead skin
What is the monitoring parameter for corns and calluses?
- Visible improvement w/in a few days
- 10-14 days for resolution of hard corn/callus
- 3-6 days for resolution of soft corn
When should you refer for a corn or callus?
- Allergic reaction develops
- Skin irritation develops that wasn’t present before and/or is moderate to severe
- Skin ulcers develop
- Any skin irritation or stinging that is bothersome to patient
- Infection develops
What are the goals of therapy for plantar warts?
- Alleviate or prevent pain due to wart
- Eradicate lesions and prevent proliferation
- Prevent recurrence
- Prevent transmission to other people
What is the assessment for plantar warts?
- Usually rough, firm hyperkeratoses that, unlike common warts on the hands, grow inwards due to pressure from walking
- Usually skin coloured but may often be grey or brown
- Tend to arise on the heel or the ball of the foot where microabrasions are more likely to occur and allow inoculation
What is the pharmacological treatment for plantar warts?
- Topical SA is first line
- 12-40% in plaster vehicle
- 5-17% in collodion-like vehicle
- 15% in a karaya gum-glycol plaster
Which types of warts are self-treatable?
Plantar and common warts
What are the ingredients and strengths in duoplant ointment?
- SA 25%
- Formalin 5%
- LA 10%
What are the ingredients and strengths in duofilm liquid?
- SA 16.7%
- LA 16.7%
What is the function of formalin?
Antiviral activity and anhydrotic action
What is the function of lactic acid?
- Corrosive properties
- Enhances SA activity
What are the ingredients and strengths in compound W liquid?
SA 20%
What are the ingredients and strengths in soluver plus liquid?
SA 27%
What are some non-pharms for plantar warts?
- Advise patients that warts are contagious
- Avoid walking barefoot
- Change shoes and socks daily
- Keep feet clean and dry
- Use waterproof tape during treatment
- Wash hands before and after cleaning feet and caring for wart
- Use good foot hygiene even when wart is gone
Why is duct tape often used for treatment of warts?
May help w/ wart removal by causing irritation
What are the recommendations when using duct tape for plantar wart treatment?
Apply to wart for 6 days then remove and soak foot
What are the monitoring parameters for plantar warts?
- Improvement w/in 1-2 weeks
- Wart removal may take 4-12 weeks (max treatment time is 12 weeks)
When should you refer for plantar warts?
- Allergic reaction develops after applying the product
- Skin is damaged and painful, inflamed, or infected
- If wart persists after 12 weeks of treatment
What are the side effects of salicylic acid?
Redness, burning, or irritation
Salicylic should not be used on ____
- Irritated, infected, or broken skin
- Moles
- Birthmarks
Is salicylic acid safe to use during pregnancy or breastfeeding?
Unknown
What ages shouldn’t use salicylic acid?
- Under 3 years
- Over 65 years
What should be done if a patient has multiple plantar warts?
Treat w/ DME/propane products only 1 wart at a time w/ a 2 week interval before treating another wart on same digit
What ages shouldn’t use DME/propane products?
Under 4 years
What are the side effects of DME/propane products?
- Aching
- Itching
- Burning
- Stinging sensation
- Can cause burns and permanent scars if used on thin skin
Are DME/propane products safe to use during pregnancy and lactation?
Unknown
What are some assessment questions for corns, calluses, bunions, and plantar warts?
- Who is the patient? How old are they?
- Where is the lesion located?
- What does the lesion look like?
- Does it look like a mole, birthmark, or is it unusual in appearance?
- Is there hair growing out of the lesion?
- How many lesions are there?
- How long have you had the problem?
- Have you used anything to treat the problem?
- Did you have any side effects or problems w/ previous treatments?
- Pregnant or breastfeeding?
What is a bunion?
Deformed big toe joint - joint is angled outward and big toe is angled inward towards other toes
What is the pathophysiology of a bunion?
- Hypertrophy of bone and soft tissues around middle of big toe
- Big toe becomes abducted and rotated, which causes prolonged pressure over 1st MTP joint
- May lead to painful inflammation and swelling of bursa over MTP joint => bunion
What are some factors that contribute to formation of a bunion?
- Inherited foot type
- Constant abnormal joint motion
- Ill-fitting shoes and high heels
- Friction from bone malformations
- Foot injuries
- RA
What are signs and symptoms of a bunion?
- Usually bilateral
- Bump on outside edge of big toe
- Thickening of skin at base of big toe
- Restricted movement of big toe
What is a differential diagnosis of a bunion?
Gouty arthritis
When would you refer a bunion?
Always
What are some non-pharms for bunions?
- Remove source of irritation
- Select properly fitting footwear
- Modify activity
- Moleskin, foam, or cushioned pads
- Bunion guard (soft polymer gel w/ no adhesive)
What are treatment options for bunions?
- Ice packs and OTC pain relievers to decrease pain and swelling (acetaminophen and NSAIDs at normal oral doses)
- Splints and orthotic devices
- Intra-articular corticosteroid injections available by physician if severe pain
- Surgery (last resort)
