Topical Treatments Flashcards
What are bases or vehicles
The substance that the active drug is dissolved in when applied to the skin
Name 6 examples of bases/vehicles
Creams, ointments, lotion, gels, pastes, foams
Describe the key features of creams
WHAT?
- Semi sold emulsification of oil in water
- Contains emulsifier & preservative
- High water content
USES
- Cools & moisturises the skin
BENEFITS
- Non-greasy, easy to apply & cosmetically acceptable
Describe the key features of ointments
WHAT?
- Semi solid grease/ oil (soft paraffin)
- Doesn’t contain preservatives
- High lipid content
USES
- Are occlusive & limit transdermal water loss
DISADVANTAGES
- Greasy & less cosmetically acceptable
Describe the key features of lotions
WHAT?
- Liquid formulations of medications
- Medication suspended in alcohol or water
USES
- Treats dry, hair-bearing areas such as the scalp
DISADVANTAGES
- Suspension in alcohol can cause stinging
Describe the key features of gels
WHAT?
- Semi solid thickened aqueous lotions/solutions
- Contains high molecular weight polymers e.g methylcellulose
USES
- Used to treat hair-bearing areas and the face
Describe the key features of pastes
WHAT?
- Semi solid finely powdered material e.g. zinc
USES
- Cool and hydrate the skin, often used in cooling bandages
DISADVANTAGES
- Stiff, greasy, difficult to apply
Describe the key features of foams
WHAT?
- Colloid with two – three phases
- Usually hydrophilic liquid in continuous phase
- With foaming agent dispersed in gaseous phase
BENEFITS
- Increased penetration of active agent
-Can easily spread over large areas
- Not greasy or oily
What are emollients
Any ointment/cream/lotion/gel
That enhances rehydration of epidermis
Emollient uses
- Dry/scaly skin conditions e.g. eczema
- Certain emollients (e.g. emulsifying ointments) can be used as soap substitutes
What topical treatments are a fire risk
Paraffin-based treatments (ointments)
Emollients containing what substance should not be left on
SLS
Why does certain emollients contain urea
urea attracts and holds water in the stratum corneum which compensates for the reduced levels of natural moisturising factor (NMF)
What is wet wrap therapy
Liberal emollients (and topical steroids if required) are applied and then covered with two layers of tubifast bandage, the first wet and the other dry
When is wet wrap therapy used
Used for very dry (xerotic) skin
Soothes the skin, introduces moisture and protects from damage caused by scratching
What are the effects of topical corticosteroids
Anti-inflammatory, immunosuppressant & vasoconstricting effects plus anti-proliferating action upon keratinocytes and fibroblasts
What topical steroids are there
Mild - hydrocortisone 1%
Moderate - Modrasone clobetasone butyrate 0.05%
Potent - Mometasone betamethasone valerate 0.1%
Very potent - Clobetasol proprionate 0.05%
When are topical corticosteroids used
Inflammatory conditions
- Particularly atopic eczema and contact dermatitis
- Psoriasis - beware rebound or triggering pustular psoriasis
- Generally used when simple emollients become ineffective
- Non-infective inflammatory dermatoses e.g. lichen planus
- Keloid scars (intralesional or tape)
Topical steroid reversible local side effects
- Acneiform eruptions
- Perioral dermatitis
- Can mask fungal infections
- ‘rebound’ psoriasis
- tachyphylaxis
- Contact allergy to hydrocortisone
- Steroid rosacea - facial flushing, telangiectasia, inflammatory lesions
Topical steroids systemic absorption side effects
- Suppression of HPA axis
- Cushing’s disease (very rare)
- Growth retardation (very rare)
Topical steroids permanent side effects
- Glaucoma and cataract
- Hirsutism (male pattern hair distribution in women)
- Striae (stretch marks)
- Thinned epidermis (atrophy) → easy bruising, purpura
- Multiple telangiectasia (dilated superficial blood vessels)
What factors affect the penetration & potency of topical steroids
- Body site e.g. thickness of stratum corneum
- Skin - permeability & Occlusion
- Specific drug - formulation & concentration
- Vehicle - affects potency and affects compliance
When would you use cream vs ointment vs lotion steroids
- Moist or weeping lesion - creams
- Dry, lichenified, scaly lesions - ointments
- Large area, hair bearing areas, exudative lesions - lotions
What can be added to topical steroids to increase penetration
Urea, salicylic acid
When might occlusive polythene or hydrocolloid dressings be used when applying topical steroids & what benefits and risks does it have
- Only used under supervision on a short term basis
- Only on areas of very thick skin (e.g. palms and soles)
- Increases absorption but also increases side effects
What is the function of calcineurin inhibitors & what skin condition is it used in
Suppress lymphocyte activation
Topical treatment of atopic eczema (especially face, children)
Benefits & disadvantages of calcineurin inhibitors
No cutaneous atrophy
May cause burning sensation
What are examples of calcineurin inhibitors
Tacrolimus, pimecrolimus
What are the four types of anti-infectives
Antiseptics
Antibiotics
Antivirals
Antifungals
Anti septic examples
•Povidone iodine (Betadine) skin cleanser
•Chlorhexidine (Hibitane, Savlon)
•Triclosan (Aquasept, Sterzac)
•Hydrogen peroxide (Crystacide)
Anti septic uses
They are bacteriostatics/bacteriocidals
•Recurrent infections ( broad spectrum)
•Skin cleansing
•Wound irrigation
Topical antiviral uses
Herpes simplex (cold sore)
Herpes zoster (shingles)
Topical antifungal uses
Candida (thrush)
Dermatophytes (ringworm)
Pityriasis versicolor
Antifungal examples
Clotrimazole
Terbinafine
Ketoconazole
Antipruiritics examples
Menthol e.g. in dermacool
Capsaicin
Camphor/phenol
Crotamiton e.g. in Eurax cream
Capsaicin MOA
depletes substance P at nerve endings and reduces neurotransmission, effect gradually builds
Keratolytics uses
Viral warts
Hyperkeratotic eczema & psoriasis
Corns & calluses
To remove keratin plaques in scalp
keratolytic example
Salicylic acid
How would you treat a wart
Mechanical paring plus
•Keratolytics e.g.Salicylic acid OR
•Formaldehyde OR
•Glutaraldehyde OR
•Silver nitrate OR
•Cryotherapy (usually liquid nitrogen) OR
•Podophyllin (genital warts)
How would you treat psoriasis
Emollients and choice of:
• Coal tar
• Vitamin D analogue
• Keratolytic
• Topical steroid
• Dithranol
What is a benefit & disadvantage of coal tar use in psoriasis
Mild solutions to strong tar - range of options
Messy & smelly
What is a benefit & disadvantage of vitamin D analogues use in psoriasis
Clean, no smell, easy to apply
Can be an irritant & so limited to 100g/wk
What is a benefit & disadvantage of dithranol use in psoriasis
Effective
Difficult to use, is an irrational & can stain/burn normal skin
How would you treat scalp psoriasis
•Greasy ointments to soften scale
•Tar shampoo
•Steroids in alcohol base or shampoo
•Vitamin D analogues
How would you treat psoriasis of the axilla/face/genitals
Topical steroids +/-
Antibacterial SS, antifungals, calcineurin inhibitors
name two cytotoxic/ anti Neoplastic therapies for basal cell carcinoma
5-Fluorouracil
Imiquimod
