Atopic Eczema Flashcards
when does atopic eczema typically start
80% of cases start in early infancy - affects 1 in 5 children
pathophysiology of eczema
epidermal barrier dysfunction – associated with filaggrin deficiency - poor skin barrier function - loss of water + allergens/irritants get in
what immune cell drives atopic eczema
TH2 cells
sites affected in infants
face + extensors
sites affected in older children
flexor surfaces - antecubital + popliteal fossae - writs + ankles
features of atopic eczema
dry, erythematous skin itchy - excoriations poorly defined borders in severe cases there may be oozing/blisters/bleeding
what is the atopic march?
eczema + asthma + hay fever
- eczema starts in infancy
- asthma starts after age of 2
- hayfever starts later, after 7 years
what is lichenification
thickening of epidermis due to chronic scratching
- exaggerated skin creases
most common cause of infective eczema
staph aureus
golden crusted lesions, typically around mouth
impetigo
- staph aureus infection
treatment of localised impetigo
topical fusidic acid
treatment of extensive impegito
oral flucloxacillin
- erythromycin if penicillin allergic
what is the cardinal symptom of eczema
itch
what is filaggrin?
where is it found?
a protein present in keratohyalin granules in the granular layer of epidermis
what is ichthyosis vulgaris
dry skin condition caused by fiaggrin deficiency
- predisposes to atopy: eczema/asthma/hayfever
clinical signs of ichthyosis vulgaris
dry fish scale skin
hyperlinear palms
sudden onset, painful, monomorphic blisters that leave ‘punched out’ erosions.
What condition?
eczema herpeticum
what causes eczema herpeticum
infection of eczematous skin by HSV 1 or HSV 2
treatment eczema herpeticum
Oral aciclovir / IV if unable to take oral
- emergency as can affect multiple organs, including encephalitis, and be fatal
what features may make you think of food allergy in infant with eczema?
history of worsening eczema + type 1 reactions / GI upset
how to you test for type 1 allergic reactions
Specific IgE (RAST) testing
skin prick testing
what type of hypersensitivty reaction is atopic eczema
type 4 delayed hypersensitivity
difference between a cream and an ointment
cream = water based
ointment = oil based
treatment of atopic eczema
avoid allergens/irritants
emollients
topical steroids
soap substitutes
name steroid ladder from mild to very potent
hydrocortisone = mild
eumovate = moderate (clobetasone)
betnovate = potent (betamethasone)
dermovate = very potent (clobetasol)
side effects of topical steroids
skin thinning - striae
steroid induced acne
telangectasia
increased skin infections
treatment of flare of eczema
continue with emollient application 3-4 times daily
topical steroids - apply once a day to inflammed area for 1-2 weeks
- potency of steroid should match severity of flare
- use mild steroids for delicate areas e.g. face/genitals
mode of action topical steroids
anti-inflammatory
vasoconstrictive
anti-proliferative
second line therapy for severe eczema / high dependance on steroids for maintenance
calcineurin inhibitors e.g tacrolimus
- anti-inflammatory agents without steroid side effects
name of calcineurin inhibitor used on face only
pimecrolimus
what are bandages impregnated with in treatment of eczema
cotton bandages impregnanted with zinc oxide
what age are anti-histamines contraindicated in
under 6 months due to increased risk of cot death
what is in:
- fucidin
- fucibet
- fucidin H
fucidin - fusicid acid
fucibet - fusidic acid + betnovate
fucidin H - fusicid acid + hydrocortisone
use for infected eczema flares (staph aureus) for max 5-10 days
what systemic agents can be used as last resort in very severe atopic eczema
azathioprine
methotrexate
cyclosporin
