dermatology otc Flashcards
what is eczema?
re often used synonymously to
describe a polymorphic pattern of inflammation, which in the
acute phase is characterised by erythema, vesiculation and in
chronic phase by dryness, lichenification and fissuring
what kind of a condition is eczema?
Non-infective, inflammatory condition
what are some of the clinical variants of eczema?
atopic, irritant contact, allergic contact, sebborrhoeic,
gravitational (varicose), asteatotic, pompholyx, discoid,
chronic hand
what are the common features of eczema?
dry, red, itchy skin
what is atopy?
a state of hypersensitivity to common
environmental allergens that may be inherited.
how does atopic ezcema occur?
Barrier lipids in lower part of the stratum corneum not formed
normally
•Results in dysfunctional skin barrier and immune system
dysregulation causing:
–Increased water loss from the stratum corneum – dryness and
itching
•Resulting in dry skin that does not retain water effectively
–Skin susceptible to allergens and often hyperreactive
–Predisposed to infection by stap.aureus
–Soap removes more lipid and reduces barrier function further
what are the signs of atopic eczema?
•Presence of itch
•Onset of signs and symptoms under the age of 2
years
–Visible flexural dermatitis
–History of other atopic disease e.g. asthma,
hayfever
•In adults:
•Generalised dryness and itching, particularly with
exposure to irritants.
what could be a potential complication of atopic eczema?
Bacterial Infection
–Scratching and excoriation of the skin causing
secondary infection, usually with Staphylococcus
aureus
–Signs: crusting, weeping, fever, malaise
what would be common allergens of allergic contact dermatitis?
- Nickel
- Topical antibiotics
- Preservative chemicals
- Fragrances
- Rubber accelerators
what would be common irritants of irritant contact dermatitis?
- Water
- Urine (nappy rash)
- Strong acid or alkali
- Bleach
- Detergents
- Abrasives e.g. sand
what are the typical features of irritant contact dermatitis?
Burning, stinging and soreness are predominant
Usual onset within 48 hours; may be immediate
Rash only in areas of skin exposed to the irritant
Resolution occurs quickly after removal of the
irritant - typically, within four days
Commonly associated with atopic eczema, which
increases the risk
xposure to friction, soap, detergents, solvents, or
wet work make diagnosis likely
what are the typical features of allergic contact dermatitis?
Redness, itch and scaling are predominant
Delayed onset
Rash may be in areas which have not been in
contact with and allergen. However, the
distribution of the rash is still helpful in
ascertaining the likely allergen
Resolution may take longer than irritant contact
dermatitis, with or without treatment
Less strong association with atopic eczema
how do you manage irritant contact dermatitis?
•Avoid irritant - 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 may aggravate existing dermatitis
•Substitution
–substitute non-irritating agents e.g. soap substitute, bath
additives
•Improve barrier function of skin with heavy emollients
•Topical corticosteroids, soap substitutes and emollients are widely
accepted as treatment of established contact dermatitis
what is complete emollient therapy?
Frequent applications of creams or ointments
–Bath oil when bathing/showering
–Routine use of emollient soap substitute
–Avoidance of regular soaps/detergents/bubble baths
when is creams more appropiate than oitments?
if skin is infected/oozing
how should you apply emollients?
•Apply at least 30-60mins before any topical steroids to avoid
dilution
•Apply in direction of hair growth to reduce risk of folliculitis
•Emollient use should generally outweigh steroid use by 10:1 in
terms of quantities used.
•Recommended quantities for use in generalised eczema are:-
–500g/week adult
–250g/week child
why is aq cream unsuitable as a leave on emollient?
as contains sodium lauryl
sulphate…fine as soap substitute
how do topical corticosteroids work?
Inhibit the production and action of inflammatory mediators, reducing
inflammation and itch
The least potent corticosteroid to produce the required effect should be
prescribed