Wk4- Topicals

Question 1

How do topicals pass through skin?

Answer 1

Diffusion (high to low gradient) by:
1. Trans-epidermal - through (intracellular) or between cells (intercellular)
2. Transappendageal - through sweat glands, hair follicules, etc

Question 2

Cream is

Answer 2

Oil in water emulsion

Question 3

Ointments are

Answer 3

Water in oil emulsions (most effective)

Question 4

What does salicylic acid do to the skin?

Answer 4

-increases water content of epidermis
-dissolves desmosomes

Question 5

What percentages of salicylic acid can perform different clinical scenarios?
5, 12, 20-40, 40-70%

Answer 5

Keratolytic
5% - soften hyperkeratosis (applied for 7 days)
12% - soften Heavy callosity (applied for 7 days)
Caustic
20-40% - removal of corns (applied 1-2days)
40-70% - verrucae (applied for 7 days with masking

Question 6

What percentages of urea can be used for clinical scenarios? 10, 30+%

Answer 6

10%- hydrate anhydrotic skin (applied daily)
30+ =- keratolytic to reduce skin and nails (under dressing for 7 days)

Question 7

When to not use caustics 6

Answer 7

-reduced arterial supply (diabetes/atherosclerosis)

-impaired venous/lymphatic drainage

-impaired pain aware needs (diabetic neuropathy)

-young patients with low pain threshold

-padding problems (getting wet/sweaty)

-fair skin/atopic individuals - overreact to breakdown

Question 8

How do you use silver nitrate for plantar warts?

Answer 8

-debridement of skin
-nitrate stick inserted into area to paint area
- continue for multiple times until completely gone

Question 9

Types of fungal treatment (topical)

Answer 9

1. Allylamines - fungicidal (Terbinafine)- first line
2. Imidazoles - fungistatic (canestene)

Question 10

How to use topical steroids / important considerations

Answer 10

• plantar area requires very potent steroid due to thickness
  -apply 2 finger tip units per foot
  -step down sterilise ladder ASAP
  -only do for 2-3 weeks, once a day
  -best used early evening with emollient