Skin Therapeutics/Topicals

Question 1

Describe a lotion

Answer 1

Liquid formulation, suspension or solution of medication in water, alcohol or other liquids. If contain alcohol, may sting. Ideal for hair bearing areas eg. Scalp

Question 2

What are gels?

Answer 2

Thickened aqueous lotions. Semi solids, containing high molecular weight polymers eg. Methylcellulose. Treat scalp, hair bearing areas, face

Question 3

What are pastes?

Answer 3

Semisolids. Contain finely powdered material. Stiff, greasy, protective, occlusive, hydrating. Often used in cooking, drying, soothing bandages. E.g. Around leaking stoma

Question 4

What are emollients used for?

Answer 4

Enhance rehydration of epidermis. All dry/scaly conditions esp eczema. Prescribe 300-500mg weekly. Frequent application. Can be used as soap substitute

Question 5

What is wet wrap therapy?

Answer 5

Used for very dry (xerotic) skin. Can apply to whole body, moisturiser etc pre applied.

Question 6

What are the modes of action of topical steroids?

Answer 6

Vasoconstrictive, anti-inflammatory, antiproliferative

Question 7

What can topical steroids do and what are the categories of these with examples?

Answer 7

Reduce inflammation, cause immune suppression.

Mild- Hydrocortisone. Moderate- Modrasone. Potent- Betamethasone. Very Potent- Clobetasol

Question 8

When are topical steroids used?

Answer 8

Eczema (dermatitis), psoriasis, other non-infective inflammatory dermatoses eg. Lichen planus. Keloid scars (usually intralesional)

Question 9

What quantities of topical steroids are needed?

Answer 9

1 Application to whole body 20-30g. Fingertip = 1/2g

Question 10

Name some side effects of topical steroids

Answer 10

Steroid rosacea, perioral dermatitis, fixed telangiectasia, thinning of the skin, purpura and stretch marks. May worsen/mask infections. Systemic absorption. Tachyphylaxis- decrease in response to anti-inflammatory effects. Rebound flare of disease (esp psoriasis)

Question 11

Describe antiseptics and list some examples

Answer 11

Have bacteriostatic or bactericidal effects e.g. Povidone iodine (Betadine) skin cleanser, chlorhexidine (Hibitane, Savlon), Triclosan (Aquasept, Sterzac), Hydrogen peroxide (Crystacide)

Question 12

Describe some clinical uses of antiseptics

Answer 12

Recurrent infections, antibiotic resistance, wound irrigation. E.g. Potassium permanganate rinse/soak use in acute exudative eczema, pompholyx

Question 13

Name some antipruritics

Answer 13

Menthol- added to calamine &other lotions & creams to impart cooling sensation.
Capsaicin- from red chilli peppers - depletes substance P at nerve endings and reduces neurotransmission, effect gradually builds. Camphor/phenol-for pruritis ani. Crotamiton e.g. eurax cream

Question 14

What are keratolytics used for?

Answer 14

Used to soften keratin; viral warts, hyperkeratotic eczema and psoriasis, corns and calluses, to remove keratin plaques in scalp

Question 15

Describe the treatment of warts

Answer 15

Mechanical paring plus : keratolytics (e.g. Salicyclic acid), formaldehyde, glutaraldehyde, silver nitrate, cryotherapy (usually liquid N), podophyllin (genital warts)

Question 16

Name some topical psoriasis treatments

Answer 16

Emollients and choice of coal tar, vitD analogue, keratolytic, topical steroid, dithranol

Question 17

Describe an ointment

Answer 17

Semisolid grease/oil (soft paraffin), no preservative. Occlusive/emollient.

Question 18

Describe a cream

Answer 18

Semisolid emulsion of oil in water-contains emulsifier & preservative. High water content

Question 19

What topical antibiotics are used in acne?

Answer 19

Clindamycin, erythromycin, tetracycline

Question 20

What topical antibiotics are used in rosacea?

Answer 20

Metronidazole

Question 21

What topical antibiotics are used in impetigo?

Answer 21

Mupirocin, fusidic acid

Question 22

What treatment is used in infected eczema?

Answer 22

Combined corticosteroid/antibacterial (short term)

Question 23

What type of antivirals would be used in Herpes simplex, eczema herpeticum and herpes zoster?

Answer 23

Topical, oral, oral

Question 24

What topical antifungals would be used in candida?

Answer 24

Antiyeast e.g. nystatin, clotrimazole

Question 25

What topical antifungals would be used in dermatophytes (ringworm)?

Answer 25

Antifungal e.g. clotrimazole, terbinafine cream

Question 26

What topical antifungals would be used in pityriasis versicolor?

Answer 26

Ketoconazole

Question 27

Describe coal tars in stable chronic plaque psoriasis treatment

Answer 27

Mild solutions to strong crude coal tar but messy and smelly

Question 28

Describe vit D analogues in stable chronic plaque psoriasis treatment

Answer 28

Clean, no smell
Easy to apply
But can be irritant
Use limited to ?100g weekly

Question 29

Describe Dithranol in stable chronic plaque psoriasis treatment

Answer 29

Effective
But difficult to use
Irritant and stains normal skin

Question 30

Describe the treatment for scalp psoriasis

Answer 30

Greasy ointments to soften scale
Tar shampoo
Steroids in alcohol base or shampoo
Vitamin D analogues

Question 31

Describe treatment for psoriasis in axilla

Answer 31

Topical steroids for face, flexures and groin /genitals; consider combination antibacterial, antifungal.

Question 32

Describe imiquimod

Answer 32

Imidazoquinoline amine
Immune response modulator
Enhances innate & cell-mediated immunity
Anti-viral, anti-tumour effects. Aldara cream, licensed for use in genital warts, superficial BCC. Also solar keratosis, lentigo maligna, Bowen’s disease, verrucae

Question 33

Describe calicneurin inhibitors

Answer 33

Tacrolimus, pimecrolimus
Suppress lymphocyte activation
Topical treatment of atopic eczema (esp face,children)
No cutaneous atrophy
May cause burning sensation on application
Risk of cutaneous infections,risk of skin cancer