Skin therapeutics & topicals

Question 1

What are the advantages and disadvantages of topical therapies?

Answer 1

Advantages:
- direct application to diseased area
- reduced systemic effects
Disadvantages:
- time consuming to apply
- difficult to dose appropriately
- messy

Question 2

What is a cream?

Answer 2

A semi-solid emulsion of oil in water which also contains emulsifier and preservative

Question 3

What are topical drugs dissolved in?

Answer 3

bases or vehicles

Question 4

What are the advantages of using a cream preparation?

Answer 4

• cooling and moisturising
• non-greasy
• cosmetically acceptable
• easy to apply

Question 5

What is an ointment?

Answer 5

A semisolid grease/oil (soft paraffin)

Question 6

Do ointments contain preservative?

Answer 6

No

Question 7

What are the advantages of using an ointment preparation?

Answer 7

• Occlusive & emollient (restricts transepidermal water loss)

Question 8

What is the disadvantage of using an ointment preparation?

Answer 8

They are greasy and so less cosmetically acceptable

Question 9

What is a lotion?

Answer 9

A liquid suspension/solution of medication in water, alcohol or other liquids

Question 10

What is the disadvantage of alcohol containing lotions?

Answer 10

They may sting

Question 11

What are lotions most useful for?

Answer 11

Treating the scalp and other hair-bearing areas

Question 12

What is a gel?

Answer 12

Thickened aqueous lotions (contains high molecular weight polymers)

Question 13

What are gels most useful for?

Answer 13

Treating the scalp & hair bearing areas as well as the face

Question 14

What is a paste?

Answer 14

A semisolid containing finely powdered materials

Question 15

What are the advantages of using a paste preparation?

Answer 15

• Protective
• Occlusive
• Hydrating
• Useful in cooling & drying bandages/dressing

Question 16

What are the disadvantages of using a paste preparation\?

Answer 16

• Stiff
• Greasy
• Difficult to apply

Question 17

What are the types of topical therapies?

Answer 17

• Emollients
• Topical steroids
• Anti infectives
• Antipruritics
• Keratinolytics
• Assorted psoriasis therapies
• Camouflage makeup
• Sunscreen

Question 18

What is the function of emollients?

Answer 18

Enhances rehydration of the epidermis

Question 19

In which conditions are emollients used?

Answer 19

All dry/scaly skin conditions (especially eczema)

Question 20

How much emollient should be prescribed (in general)?

Answer 20

300-500g weekly (needs frequent application)

Question 21

Certain emollients can be used as soap substitutes. T/F

Answer 21

True

Question 22

Are proprietary or non-proprietary emollients more expensive? Why might it be appropriate to prescribe the more expensive of the two?

Answer 22

Proprietary. Often these are more cosmetically acceptable which is important in compliance

Question 23

When is wet wrap therapy used?

Answer 23

On very xerotic (dry) skin

Question 24

What is the disadvantage of wet wraps?

Answer 24

Difficult & time consuming to apply

Question 25

What are the effects of topical steroids?

Answer 25

Vasoconstrictive, anti-inflammatory and anti-proliferative

Question 26

List, in order of increasing potency, some topical steroids

Answer 26

Hydrocostisone > Butyrate/Modrasone/Clobetasone > Mometasone/Betamethasone/Valerate > Clobetasol/Proprionate

Question 27

What are some of the uses of topical corticosteroids?

Answer 27

Eczema, psoriasis, non-infective inflammatory dermatoses (e.g lichen planus) & (intralesional) keloid scars

Question 28

How much ointment is needed to apply ointment to the entire (adult) body? How much skin should a fingertip unit cover?

Answer 28

20-30g. Two hand areas

Question 29

What are the possible side effects of topical steroids?

Answer 29

Thinning of the skin/atrophy, purpura, stretch marks, steroid rosacea, fixed telangectasia, perioral dermatitis, worsening/masking of infection, systemic effects, tachyphylaxis, rebound flare

Question 30

Antiseptics have bacteriostatic but not bactericidal effects. T/F

Answer 30

False - they can have either

Question 31

List some antiseptics

Answer 31

Povidone iodine (betadine) Chlorhexidine Triclosan Hydrogen peroxide (crystacide)

Question 32

What are the uses of antiseptics?

Answer 32

Recurrent infections, antibiotic resistance & wound irrigation

Question 33

Potassium permanganate soaks can be used in every type of eczema apart from acute exudative (pompholyx). T/F

Answer 33

False - it is used almost exclusively in pompholyx eczema

Question 34

List some topical antibiotics and their uses

Answer 34

+ Clindamycin, erythromycin and tetracycine - Acne + Metronidazole - Rosacea + Mupirocin, fusidic acid - Impetigo + Antibacterial & corticosteroid combo - Infected eczema

Question 35

When might antiviral treatment be useful?

Answer 35

If given within a few days of symptom onset it can be useful in: - Herpes simplex (cold sore) - Eczema herpetiform (oral preparation) - Herpes simplex (oral preparation)

Question 36

List some topical antifungals and their uses

Answer 36

+ Antiyeast (clotrimazole, nystatin) - Candida + Clotrimazole, terbinafine - Dermatophytes + Ketoconazole - Pityriasis versicolor

Question 37

List some antipruritics

Answer 37

Menthol, Capsaicin, Camphor/phenol, Crotamiton

Question 38

What is menthol used for?

Answer 38

Usually added to calamine lotions to provide a cooling effect (dermacool)

Question 39

What is the mechanism of action of capsaicin?

Answer 39

Uses up substance P at nerve endings, reducing neurotransmission and so itching. Has a cumulative effect over time

Question 40

What is camphor and phenol used for?

Answer 40

Pruritus ani

Question 41

What are keratinolytics used for?

Answer 41

Viral warts, hyperkeratotic eczema or psoriasis, corns and calluses, removal of keratin plaques

Question 42

Give an example of a kerainolytic

Answer 42

Salicylic acid

Question 43

How are warts treated?

Answer 43

Mechanical parring AND: - keratinolytics - formaldehyde - glutaraldehyde - silver nitrate - cryotherapy (liquid nitrogen) - podophyllin (genital warts ONLY)

Question 44

What are the mainstay of topical psoriasis treatments?

Answer 44

Emolliants AND: - coal tar - vitamin D analogues - keratinolytic - topical steroid - dithranol

Question 45

What are the disadvantages to coal tar?

Answer 45

Messy and smelly

Question 46

What are the advantages and disadvantages of vitamin D analogues?

Answer 46

``` Advantages: - clean - no odour - easy to apply Disadvantages: - irritant (max 100g weekly) ```

Question 47

How is scalp psoriasis treated?

Answer 47

Greasy ointments, tar shampoo, steroids (alcohol base OR shampoo), vitamin D analogues

Question 48

When are topical steroids considered for used in psoriasis?

Answer 48

When the affected areas involve the face, flexures or groin

Question 49

What combination of drugs may be considered in psoriasis?

Answer 49

Antifungal and antibacterial (rarely)

Question 50

What is imiquimod?

Answer 50

An immune response modulator which enhances innate and T-cell mediated immunity. Antiviral & antitumor

Question 51

When is imiquimod used?

Answer 51

Superficial BCC, genital warts, solar keratosis, lentigo maligna, bowen's, verruca

Question 52

Give some examples of calicneurin inhibitors

Answer 52

Tacrolimus, pimecrolimus

Question 53

What is the mechanism of action of calicneruin inhibitors?

Answer 53

Suppress lymphocyte activation

Question 54

What are calicneurin inhibitors used for?

Answer 54

Atopic eczema treatment (mostly on faces or children)

Question 55

What are the advantages and disadvantages of calicneurin inhibitors?

Answer 55

``` Advantages: - no atrophy Disadvantages: - may cause burning sensation - MAY increase the risk for skin infections and cancer ```

Question 56

What are some general side effects of topical therapies?

Answer 56

Burning/irritation, contact allergic dermatitis, local toxicity, systemic toxicity