Eczema Flashcards
What is another name for eczema?
Atopic dermatitis
Where on the body does eczema commonly affect?
Flexural areas
What demographic is most commonly affected by eczema?
Babies and children
by adult life 60% have cleared
The main diagnostic criteria is ‘an itchy skin conditions in the last 12 months’; what are the other criteria of which there should be 3 to diagnose eczema?
- Onset before age 2
- History of flexural involvement
- History of generally dry skin
- History of other atopic disease (or history in 1st degree relative if under 4)
What are the 3 components of pathogenesis of eczema?
Genetics
Epidermal barrier dysfunction
Environmental factors
What is the key gene causing eczema?
Filaggrin
What r the layers of skin again? And what is found there?
Epidermis
Dermis
Hypodermis
Sebaceous glands
Hair follicles
Blood vessels
3 key terms for pathology of eczema?
SPONGIOSIS (intercellular oedema)
ACANTHOSIS (thickening of the epidermis)
INFLAMMATION (superficial perivascular lymphohistiocytic infiltrate)
What is the main clinical feature of eczema?
Itch !
Describe the common distribution of eczema
Flexures, neck, eyelids, face, hands, feet
Tends to spare nappy area
Describe acute changes that can be found in eczema
Pruritis, erythema, scale, papules, vesicles
Exudate, crusting, excoriation
Describe chronic changes that can be found in eczema
Lichenification
Plaques
Fissuring
Atopic family history is also associated with eczema e.g.
Atopic eczema
Asthma
Hay fever (allergic rhinitis)
Food allergy
What are the exogenous types of eczema?
Contact dermatitis (irritant or allergic)
Lichen simplex
Photoallergic or photoaggravated eczema
What are the endogenous types of eczema?
Atopic Discoid Venous Seborrhoeic dermatitis Pompholyx Juvenile plantar dermatitis Asteatotic
What type of hypersensitivity is allergic contact dermatitis?
Type 4
How long can it take to develop a reaction in allergic contact dermatitis?
48-2 hrs
Describe the action of T cells in AC dermatitis?
They are sensitised to an antigen and when they encounter it initiate mast cell degranulation, vasodilatation and neutrophil stimulation
What 2 things can the skin be injured by in irritant contact dermatitis?
1) friction (micro-trauma, cumulative)
2) environmental factors (cold, over-exposure to water, chemicals such as acids, alkalis, detergents and solvents)
What people can be more commonly affected by irritant contact dermatitis?
Hairdressers
NHS staff
Cleaners (soap can accumulate e.g. under ring)
Babies - nappy rash
What is applied to the skin in patch testing?
Potential allergens
Baseline/standard series applied to all patients
What is the timeline for patch testing?
Applied Mon
Remove Wed
Re-assess Fri
What is the predilection for infant seborrhoeic dermatitis?
Sclap, proximal features
What is the usual age of infant seborrhoeic dermatitis and how quickly does it clear up?
<6 months
Often clears within weeks of treatment
What fungus is increased in the scaly epidermis of dandruff in adult seborrhoeic eczema?
Malessezia yeast
What is the appearance of adult seborrhoeic eczema?
Red, sharply marginated lesions covered with greasy looking scales
Found in areas rich in supply of sebaceous glands (scalp, face, upper trunk)
What can be a pre-cursor for seborrhoeic eczema?
Dandruff
How is seborrhoeic eczema treated?
Topical anti-yeast (ketoconazole)
What test should be considered if SE is severe?
HIV test
What is the appearance of discoid eczema?
Circular plaques; may develop at sites of trauma/irritation (cause often unknown)
What is often needed to manage discoid eczema?
Strong steroids
Where does pompholyx/vesicular eczema usually affect?
Palms and soles
Intensely itchy
What is the usual onset of pompholyx/vesicular eczema?
<40 yrs
Sudden onset of crops of vesicles
What can resolution of pompholyx/vesicular eczema include?
Desquamation
What is the appearance of asteatotic eczema?
V dry skin; cracked, scaly appearance; commonly affects shins (from heat or excessive washing etc)
What is venous eczema caused by?
Increased venous pressure (‘stasis’ or ‘varicose’ eczema); blood leaks out and causes inflammation
What part of the body is usually involved? What pathology is associated?
Ankle/lower leg - oedema
What can help in venous eczema?
Resolution of oedema - compression stockings
What is eczema herpeticum?
Disseminated viral infection
Herpes Simplex 1 and 2
What are the common clinical features associated with eczema herpeticum?
Fever/unwell
Itchy clusters of blisters and erosions - monomorphic pattern of vesicles which coalesce and crust
Swollen lymph glands
What is to be considered in eczema herpeticum?
Admission !
Antivirals
Possible econdary bacterial infection
What is the treatment plan for eczema?
- Patient education
- Avoid causative/exacerbating factors
- Emollients (moisturisers) (ointments, creams, lotions)
- Soap substitutes
- Intermittent topical steroids (in exam prob)
- Sometimes antihistamines/antimicrobials
- Calcineurin inhibitors
What are the low v potent topical steroids used to treat eczema?
Hydrocortisone (low)
Betamethasone (potent)
(but irl would look up in BNF)
What calcineurin inhibitors are used in eczema?
Topical pimecrolimus and tacrolimus
2 treatments for severe eczema?
UV light
Immunosuppression (azathiorprine, cyclosporin, methotrexate, mycophenolate mofetil) - not common
What can result from steroid use in eczema?
Striae - common in areas of thinner skin like axilla - use on back etc is fine
(prob not important) Looking forward what could be 2 treatments for eczema?
Crisaborole (topical PDE-4 inhibitor)
Dupilumab (1st biologic for eczema patients; IL-4/IL-13 inhibitor)
