ECZEMA Flashcards
Causes of atopic eczema?
No single cause:
- strong genetic susceptibility
- filaggrin gene mutations causing skin barrier dysfunction
- T-helper cell dysregulation - predominance of Th2 cells rather than Th1
- environmental factors e.g. early life exposure to irritants, pruritogens etc
Genetic factors for atopic eczema?
70% have a positive FHx of atopic disease
80% of children if both parents affected and 60% if only 1 parent affected
Twin studies showed a concordance rate of 85%
Filaggrin gene function?
Filaggrin gene is essential for the conversion of keratinocytes to the protein/lipid squames that make up the outermost barrier layer of the stratum corneum
Loss of this function causes skin barrier dysfunction
How does skin barrier dysfunction lead to atopic eczema?
Water loss from the skin leads to dryness and itching which makes the skin susceptible to allergens = hyperreactivity and induction of IgE and autoantibodies
This also predisposes skin to colonisation or infection by microbes which also leads to an inflammatory response and further damage to the skin barrier
Triggers for atopic eczema?
Soap and detergents
Animal dander
House-dust mites
Extreme temperatures
Rough clothing - synthetics, silk, dyes
Pollen
Certain foods
Skin infections
Stress
Hormonal triggers - premenstrual or pregnancy
Diet - milk, egg, wheat, soy, peanuts
Prevalence of atopic eczema?
Prevalence is increasing
Presents most frequently in childhood but can present at any age
Affects 10-30% of children
Up to 90% of cases occur before 5 years of age
Only 30% of those with eczema first develop symptoms as adults
Complications of atopic eczema?
Infection - staph aureus, herpes simplex, superficial fungal
Psychological problems - distress, depression, behavioural problems, poor self image, sleep issues
Asthma, allergic rhinitis, food allergy, eosinophilic oesophagitis
Typical pattern of atopic eczema?
Episodic disease of flares and remissions - may occur as frequently as 2 or 3 times each month
Prognosis of atopic eczema?
Gradual improvement in adult life - clears in 75% of children by 16
How commonly do children with eczema go on to develop asthma or hay fever/
Asthma in 30-50%
Hay fever in 30-80%
Where is eczema most common in adults?
On the hands
Where is eczema most common in children?
Flexure of limbs and creases of face+neck
Where is eczema most common in infants?
Face, scalp, extensor surfaces of limbs
Signs of chronic eczema?
Lichenified skin
Follicular hyperkeratotic papules (karatosis Pilaris) - extensor upper arms, buttocks, anterior thighs
Criteria for eczema?
An itchy skin conditions plus 3 or more of the following:
Visible flexural eczema involving the skin creases or visible eczema on the cheeks/extensor areas in children younger than 18 months
PHx of flexural eczema
PHx of dry skin in the last 12 months
PHx of atopic disease
Onset of signs and symptoms before age 2
Severity of eczema?
Mild - areas of dry skin and infrequent itching
Moderate - dry skin, frequent itching and redness
Severe - widespread dry skin, incessant itching and redness
Infected - weeping, crusted, pustules, fever or malaise
Managing mild eczema?
Frequent and liberal use of emollients
Mild topical corticosteroid
Self-care advice for eczem,a?
Frequent and liberal use of Emollients even when skin is clear
Avoid trigger factors e,g. Soap substitutes
Avoid scratching the eczema - trim nails + anti-scratch mittens
Management of moderate eczema?
Emolliennts
Moderately potent topical corticosteroid for on inflamed areas
If severe itch then 1 month trial of non-sedating antihistamine
Consider a minatennce regimen of topical corticosteroids to control areas of skin prone to frequent flares
Management of severe eczema?
Emollients
Potent topical corticosteroid
If severe itch - 1 month trial of non-sedating antihistamines or a short course of a sedating antihistamine if affecting sleep
If severe, extensive disease causing psychological distress - short course of oral corticosteroid
Consider maintenance regimen of topical corticosteroids to control areas of skin prone to frequent flares
WHAT IS WET WRAPPINH?
large amounts of emollient (and sometimes topical steroids) applied under wet bandages
How should you apply emollients and topical steroids?
if a topical steroid is also being used the emollient should be applied first followed by waiting at least 30 minutes before applying the topical steroid
Non-sedating antihistamine options?
Cetirizine, loratidine or fexofenadine
Steroid ladder: mild
Hydrocortisone
Steroid ladder: moderate
Betamethasone valerate 0.025%
Clobetadone butyrate 0.05% (eumovate)
Steroid ladder: severe
Betamethasone valerate 0.1% (betnovate)
When should you consider admission to hospital for eczema?
If you suspect eczema herpeticum
Managing infected eczema?
Antibiotic - flucloxacillin
If localised areas consider topical fusidic acid
Prescribe new supplies of topical emollients/steroids to try to reduce the risk of further infection
Most common organism that causes infected eczema?
Staph aureus
What causes eczema herpeticum?
Herpes simplex virus 1 or 2
What does eczema herpeticum look like?
A rapidly progressing painful rash
Monomorphic punched-out erosions - circular, depressed, ulcerated lesions usually 1-3mm in diameter
Management of eczema herpeticum?
Admit to hospital
IV aciclovir
Side effects of topical steroids for eczema?
Thinning of the skin - more prone to flares, bruising, tearing, stretch marks and telangiectasia
Systemic absorption is possible
Management options for severe non-responsive eczema?
Phototherapy
Immunosuppressants - azathioprine, Ciclosporin, methotrexate
Who does periorificial dermatitis most commonly affect?
Women aged 20-45
What is periorificial dermatitis?
A relatively common chronic inflammatory skin eruption
Preferentially targets cutaneous orifices e.g. around eyes, nostrils, mouth
Types of periorificial dermatitis?
Perioral
Periocular
Perinasal
Genital periorificial dermatitis
What often triggers periorificial dermatitis?
Topical or, to a lesser extent, inhaled corticosteroids
Where is periorificial dermatitis most common?
Perioral - note the skin immediately adjacent to the vermillion border of the lip is spared
Features of periorificial dermatitis?
Clustered, erythematous papules, papulovesicles and papulopastules
Management of periorificial dermatitis?
Topical or oral antibiotics
Note: steroids may worsen Sx
What is pompholyx?
Aka dyshidrotic eczema
A type of eczema that affects the hands or feet
Types of pompholyx?
Cheiropompholyx - hands
Pedopompholyx - feet
What can precipitate pompholyx eczema?
Humidity/sweating
High temperatures
Features of pompholyx?
Small blisters on palms and soles
Often intensely itchy and may have a burning sensation
Once blisters burst the skin may become dry and cracked
Management of pompholyx?
Cool compresses
Emollients
Topical steroids
