Skin Therapeutics Flashcards
What are the advantages of topical treatments?
Direct application, reduced systemic effects
What are the disadvantages of topical treatments?
Time consuming, correct dosage can be difficult, messy
What are drugs used on the skin dissolved in?
Bases or vehicles
What are creams?
Semisolid emulsions of oil in water that contain emulsifier and preservative
What are some features of creams?
High water content cools and moistens skin, easy to apply, cosmetically acceptable
What are ointments?
Semisolid grease/oil (soft paraffin) without preservatives
What are some features of ointments?
Occlusive and emollient, restrict transepidermal water loss, greasy so less cosmetically acceptable
What are lotions?
Liquid formulations-suspension/solution of medication in water/alcohol/other liquids (may sting if alcoholic)
Where are lotions used to treat?
Hair bearing areas, the scalp
What are gels?
Thickened aqueous lotions-semisolids containing high molecular weight polymers (e.g methylcellulose)
Where are gels used to treat?
The scalp, hair bearing areas, the face
What are pastes?
Semisolids that contain finely powdered material (e.g ZNO)
What are some advantages and disadvantages of pastes?
Protective, occlusive and hydrating
Stiff, greasy and difficult to apply
When are pastes used?
Often used in cooling, drying, soothing bandages
What are foams?
Colloid with two/three phases-usually hydrophilic liquid in continuous phase with foaming agent dispersed in gaseous phase
What are some advantages of foams?
Increased penetration of active agents (e.g steroid, vitamin D), spread easily over large areas of skin, no greasy/oily film
What are the types of topical therapies?
Emollients, Anti-infective agents, Kerolytics, Topical steroids, Antipruritics, Psoriasis therapies
What do emollients do and what are they used for?
They enhance rehydration of epidermis; for all dry/scaly conditions (especially eczema)
How much of an emollient should be prescribed?
300-500g-needs frequent application
What can emollients be used as a substitute for?
Soap
What are some emollient prescribing tips?
Apply immediately after bathing, apply in direction of hair growth, make skin and surfaces slippery (hazard), use clean spoon/spatula to remove skin from tub (risk of bacterial contamination), fire risk if paraffin-based, avoid those containing SLS in “leave on” products
What is the cost of non-proprietary emollients?
Under £5/500g (e.g liquid paraffin, white-soft paraffin)
What is the cost of proprietary emollients?
Between £5 to > £30 (more cosmetically acceptable which is important for compliance)
When is wet wrap therapy used and what are some of its issues?
Used for very dry skin (xerotic skin); difficult and time consuming to apply
What are some properties of topical corticosteroids?
Vasoconstrictive, anti-inflammatory, anti-proliferative
What is a side effect of topical corticosteroids?
Immune suppression
What is an example of a mild topical corticosteroid?
Hydrocortisone (1%)
What are some examples of moderate topical corticosteroids?
Modrasone, Clobetasone, Butyrate 0.05%
What are some examples of potent topical corticosteroids?
Mometasone, Betamethasone, Valerate 0.1%
What are some examples of very potent topical corticosteroids?
Clobetasol, Proprionate 0.05%
What are some things that topical corticosteroids are used for?
Eczema, psoriasis (flexures, face, hairline, scalp), keloid scars (intralesional), other non-infective inflammatory dermatoses
How much topical corticosteroid is needed to cover all of an adults body?
20-30g
How much does 1 finger amount (1/2g) of topical corticosteroid cover?
2 hand areas
What are some side effects of topical corticosteroids?
Thinning of skin, purpura, stretch marks, fixed telangectasia, steroid rosacea, perioral dermatitis, may worsen or mask infections, systemic absorption, tachyphylaxis, rebound flare of disease
What are some effects of the systemic absorption of topical corticosteroids?
Adrenal suppression and Cushings syndrome
What is tachyphylaxis?
A decrease in response to anti-inflammatory effects
What condition in particular is associated with rebound flare caused by topical steroids?
Psoriasis
What effects can antiseptics have?
Bacteriocidal and bacteriostatic
What are some examples of antiseptics?
Povidone iodine (Betadine), skin cleanser, chlorhexidine (Hibitane, Savlon), triclosan (Aquasept, Sterzac), hydrogen peroxide (Crystacide)
What are the clinical uses of antiseptics?
Recurrent infections, antibiotic resistance, wound irrigation, potassium permanganate rinse used in acute exudative eczema
What are some conditions where antivirals are used in the treatment?
Herpes simplex (cold sore)=topical antiviral Eczema herpeticum=oral antiviral Herpes zoster (shingles)=oral antiviral
What are some of the antifungals used to treat Candida (thrush)?
Antiyeasts (e.g nystatin, clotrimazole)
What are some examples of antifungals used to treat dermatophytes (ringworm)?
Clotrimazole, terbinafine cream
What antifungal is used to treat Pityriasis versicolor?
Ketoconazole
What are some examples of antipruritics?
Menthol, capsaicin, camphor/phenol, crotamiton (e.g Eurax cream)
What is menthol used for?
Added to calamine and other lotions/creams to impart cooling sensation (e.g Dermacool)
How does capsaicin work and what is it derived from?
Depletes substance P at nerve endings and reduces neurotransmission, effect gradually builds; from red chilli peppers
What is camphor/phenol used to treat?
Pruritus ani
When is crotamiton used?
After treatment of scabies to resolve residual itch
What are keratolytics used for?
Used to soften keratin-removes keratin plaques on scalp
What conditions are keratolytics used to treat?
Viral warts, hyperkeratotic eczema, psoriasis, corns, calluses
How are warts treated?
Mechanical paring plus:
Keratolytics (e.g salicylic acid), formaldehyde, glutaraldehyde, silver nitrate, cryotherapy, podophyllin
What chemical is usually used in the cryotherapy of warts?
Silver nitrate
What kind of warts is podophyllin used to treat?
Genital warts
What are some topical treatments for psoriasis?
Emollients plus choice of coal tar, vitamin D analogue, keratolytic, topical steroid or dithranol
What are the treatments for stable chronic plague psoriasis?
Coal tar, vitamin D analogues, dithranol
What are some features of coal tar?
Mild solutions up to strong crude coal tar used, messy, smelly
What are some features of vitamin D analogues?
Clean, no smell, easy to apply, can be irritant, use limited to 100g weekly
What are some features of dithranol?
Effective, difficult to use, irritant, stains normal skin
What are the treatments used for scalp psoriasis?
Greasy ointments to soften scale, tar shampoo, steroids in alcohol base/shampoo, vitamin D analogues
What are some examples of treatments for psoriasis of the axilla?
Topical steroids (face/flexures/groin/genitals), consider combination of antibacterial/antifungal, calcineurin inhibitors
What are some side effects of topical treatments?
Burning, irritation, local/systemic toxicity, contact allergy dermatitis
