Skin OTC - Contact Dermatitis Flashcards
Define contact dermatitis.
Skin inflammation in response to external agents.
What are the 2 types of contact dermatitis?
Allergic
Irritant
Give e.g. of common allergens
Nickel
Topical ABx
Preservative chemicals
Fragrances
Rubber Accelerators
Give e.g. of common irritants.
Water
Urine (nappy rash)
Strong acid/alkali
Bleach
Detergents
Abrasives e.g. sand
Explain the management of irritant contact dermatitis.
Avoid irritants - occupational considerations.
Protection (commonly involves hands - gloves mainstay of protection with a cotton liner or worn over cotton gloves. Take gloves off on regular basis as sweating can aggravate existing dermatitis.)
Substitution (Substitutes non-irritating agents e.g. soap substitutes, bath additives)
Improve skin barrier with heavy emollients.
Topical CS, soap substitutes and emollients = widely accepted as tx of established contact dermatitis.
What are the symptoms of allergic contact dermatitis?
Red rash, inflammation, vesicles
Itchy
Affecting any area of the body
Repeated exposure to irritant can cause skin to become dry, scaly and thicken.
What are the OTC treatment options for contact dermatitis?
Hydrocortisone 1% cream.
- Only for mild/moderate eczema, contact dermatitis and insect bites.
- Applied up to BD for no more than 7 days.
- Don’t apply to broken/infected skin, above neck except earlobes.
- Avoid in pregnancy/ano-genital area.
What factors do you need to consider for choice of emollients?
Product should a px’s needs
Creams vs. Ointments:
- Creams less effective than ointments and may sting more but less greasy and can feel cool/light on skin.
- Creams more appropriate if skin is infected/oozing to avoid occlusion.
- Ointments better on dry, scaly, thick areas.
How do you apply emollients?
Apply at least 30-60 minutes before any topical steroids to avoid dilution.
Apply in direction of hair growth to reduce folliculitis.
Emollients should generally outweight steroids by 10:1. Recommended quantities for use in generalised eczema: 600g/week (adults), 250g/week (child)
Aq cream unsuitable as a leave on emollient as it contains sodium lauryl sulphate fine as soap substitute.
NPSA alert - fire hazard with paraffin based skin products (alert issued following px fatality
Explain the use of topical CS.
For eczema flares, psoriasis and other inflammatory skin conditions.
Inhibits production and action of inflammatory mediators reducing inflammation and itch.
Least potent CS is Rx.
Where skin is thin e.g. face and genitals (mild CS)
Where skin is thick more potent CS is used
Children < 1 yr mild only
OTC licence: Hydrocortisone 10yrs+, Clobetasone 12+
Not for face/genitals
What are the common s/e of topical CS?
Atrophy (skin becomes thin and easily bruised. More likely where skin is already thin. Skin may recover gradually after stopping tx but original structure may never return.
Irreversible striae atrophicae (stretch marks) and telangiectasia (red lesions on the skin) Prolonged or excessive use of potent steroids causes dermis to lose its elasticity and stretch marks (striae) to appear which are permanent.
Masking infection (also spread and worsening of untreated infection)
Acne like pustules (worsening of acne or rosacea)
Mild depigmentation (reversible)
Systemic: adrenal suppression and Cushing’s syndrome.
C/I more potent CS in infants < 1 yr.
LT (1-3 yrs)
Adherence
+/- when used correctly.
Potent prep can cause skin atrophy with LT use, often under used due to concern about s/e.
Facial eczema - no string potency steroids.
What counselling is given for topical CS?
Topical CS not used as emollients.
Amount of topical CS ‘ fingertip units.’
When to use CS - not applied for at least half an hour after applying emollients to avoid dilution of CS or its spread to unaffected areas.
How do you apply a topical CS? (1)
Fingertip units - cover an area 2x the size of the flat of the px’s hands. The px should be instructed to use 1 fingertip unit (this is the amount of cream that covers from the tip of the index finger to the first crease of the finger when squeezed from the tube)
Give e.g. of other treatment for atopic eczema.
Sedative antihistamines (ST use to control itch and scratch, especially at night)
Bandaging ‘wet wrapping’ (Generous emollients or mild CS applied to skin covered with a layer of wet cotton bandage. Can over wrap with a dry bandage can be lead in place overnight.)
Phototherapy - controlled UV exposure with psoralen photosensitiser. (Increased skin cancer LT)
Systemic immunosuppression: Ciclosporin, azathioprine, MTX, systemic CS)
Tacrolimus/Pimecrolimus: Not used to tx mild atopic eczema. If it’s moderate/severe eczema, not first line. Considered if max strength and potency of topical CS hasn’t worked and it there’s serious risk of SE.
