Eczema Flashcards
What are the core characteristics of eczema?
pruritus
erythema
skin dryness
scaling
What are the lesions like in acute eczema?
vesicles or blisters
oedema
erthema
often associated with:
pain
bleeding
weeping
What are the lesions like in chronic eczema?
skin fissures
lichenification develop
erythema
What is lichenification? (what causes it)
It means the skin has become thickened and leathery.
(This often results from continuously rubbing or
scratching the skin)
What is the difference between dermatitis and eczema?
They are interchangeable
Explain the pathology seen in acute eczema?
Erythema - Dermal vessels dilate
Vesicles and exudate - epidermal oedema causes separation of keratinocytes ‘spongiosis’
Oedema of skin - Inflammatory cells invade the dermis and epidermis
What causes a rapid change in eczema lesion appearance in acute eczema?
Scratching
Explain the pathology seen in subacute eczema?
Less vesicles -> Less spongiosis
Scaling -> Epidermal cells malfunction:
1) acanthosis (thickening of epidermis)
2) hyperkeratosis (increased keratin production)
3) parakeratosis
Explain the pathology seen in chronic eczema?
Thick, roughened skin, dry + scaly (lichenification)
sometimes fissured
the above due to -> Marked acanthosis, hyperkeratosis and parakeratosis, lichenification
Erythema due to -> Persistent vessel dilation and inflammatory cells
What is acanthosis?
thickening of epidermis
What is parakeratosis? (where does this occur naturally and how can this help identify its presence)
persistence of the nuclei
of keratinocytes
as they rise into the horny layer of the skin
(it occurs normally in the epithelium of the true mucous membrane of the mouth and vagina. hence why the mucous membranes are purple)
What are the types of endogenous eczema?
Atopic
Seborrhoeic
Asteatotic
Varicose
Discoid
What are the types of exogenous eczema?
Irritant
Infective
Allergic contact
What is the difference between endogenous and exogenous eczema?
Endogenous -> internal factor
Exogenous -> external factor
What is varicose eczema also known as?
gravitational/stasis eczema
What is asteatotic eczema?
Mainly affects >60’s
Asteatotic eczema can be linked to a decrease in the oils on the skin surface
due a number of factors
What is patch testing used for with regards to dermatitis?
To test for causes of potentially allergic contact eczema
How long is patch testing conducted for?
Put on and checked at:
48hrs
72hrs
What is the key part of the hx for allergic contact eczema?
Where the rash started
as this will tell you what the pt is allergic to
Describe where atopic eczema rashes tend to be on differenct age groups?
Baby -> on face
Older -> localises to flexures
What is the cause of atopic eczema?
It is essentially not known, but is thought to be linked to the fillagrin gene
which encodes a skin barrier protein
thus there is a defect in the skin barrier
which leads to abnormal stimulation of the immune system
IgE Ab play a role too
What is atopy?
Familial predisposition to:
atopic eczema
allergic rhinitis (hay fever)
allergic asthma
What proportion of children have atopic eczema at some point in their lives?
15%
What is the typical age of onset of atopic eczema?
Below 2 yrs
Does severity of atopic eczema tend to get worse or better with age?
Better with age
What proportion of children will grow out of atopic eczema by the age of 2 yrs + adolescence?
50% will grow out of it by 2 yrs
80% grown out of it by adolescence
Skin prick testing for what, is normally positive in atopic eczema?
House dusk mite
At what age does discoid eczema often arise?
At any age
What is a common adverse outcome of discoid eczema?
Infection of the lesion
Where and why does varicose eczema occur?
Occurs on the lower legs of the elderly
Due to a combination of:
dry skin (asteototic eczema) and
varicose veins
What is the key to treating varicose eczema?
Compression of the leg/lesion
What is pompholytic eczema?
a.k.a. Dyshidrosis
eczema of unknown cause characterized by
small blisters
on the hands or feet
What is the extra treatment of seborrheic eczema and why?
antifungals, as there is often co-infection of the lesion(s) with
pityrosporum yeast species
What is seborrheic eczema?
eczema that affects sebaceous glands (associated with hair follicles)
What is the most common exacerbating factor for atopic eczema?
House dust mite
What are the principles for treatment of all types of eczema?
Avoid any exacerbating factors
Emollient for dryness as soap substitutes
Topical steroid for active areas
What are the different strengths of topical steroids and give examples?
Mild (1% Hydrocortisone acetate)
Moderate (Hydrocortisone butyrate)
Potent (Betamethasone/mometasone)
Very potent (Clobetasone)
What are the different types of emollient? (give examples)
1) Creams (aqueous cream)
2) Ointments (white soft paraffin)
3) Bath oils (Oilatum)
What are generally the most effective yet under-used emolients?
Ointments are best, but poor compliance as too greasy
What are the side-effects of topical steroids and how can these be avoided?
Skin-thinning
use finger-tip unit
Other than the classical 1st-line treatments of eczema what other 1st-line treatments are there? (put in indication too)
Occlusive bandaging (reduce excoriation of lesion, esp. in children)
Antibiotics (if infected)
topical tacrolimus and pimecrolimus (if on face or if “stuck” on strong steroid)
What are the types of occlusive bandaging used in eczema?
1) Tar
2) Zinc paste
3) Wet wraps
What are signs that eczema is infected?
erythema
exuding pustules
Which antibiotics are commonly used in eczema?
Flucloxacillin
Erythromycin
What is the benefit of topical tacrolimus and pimecrolimus?
They do not cause skin thinning
What is the problem with topical tacrolimus and pimecrolimus?
They are extremely expensive
What are the 2nd/3rd line treatments for eczema?
Oral steroids – short term
Ultraviolet light
Cyclosporin A (Monitor BP, renal function, risk malignancy)
What should be monitored in Cyclosporin A? (explain why)
Monitor BP (can cause HTN)
renal function (can cause kidney dysfunction)
increased risk malignancy, thus monitor
What are the risks of using topical steroids on the face?
telangectasia
perioral dermatitis
eye problems
skin thinning
What is the best form of topical steroid and why?
steroid ointment, due to:
beneficial emollient effect and
reduced risk of medication allergy with long-term use
How can topical steroid s/e’s be reduced?
Use an ointment
Twice daily for only a few days
Only treat active areas
