eczema Flashcards
What is another name for eczema
dermatitis
What is atopic eczema - atopic dermatitis
Inflammatory skin condition which affects the flexural areas
Who does atopic dermatitis occur more in
children and babies
What is the definition of atopic eczema
An itchy skin condition that was in the last 12 months which has 3 of the following :
Onset before 2
flexure involvement
generally dry skin
Family history of other atopic diseases - asthma, hay fever and food allergy…
What gene is commonly affected in atopic eczema
Filaggrin gene
What happens in atopic eczema
There is barrier dysfunction:
Spongiosis - intracellular oedema in the epidermis
Acanthosis - thickening of the epidermis
Inflammation - superficial perivascular lymphohistiocyte infiltrate
What is the presentation of atopic dermatitis
Itch
distribution in the flexers, neck, eyelids, face, hands and feet
Acute changes:
pruritis - feeling of wanting to itch
erythema
scale
papule
vesicles
exudate
crusting
excoriation
Chronic changes - lichenification - thickening of the skins which can become plaques and have the potential to split
What is allergic contact dermatitis
type 4 hypersensitivity - T cell mediated 48-72 hour long delay for reaction to occur
Antigen presenting cells take the harmless substance and present it to the lymph nodes and the T cells expand and produce antibodies for the harmless substance
The T cells are released into the blood stream and the next time the harmless substance (hapten) is encountered, the antibodies will be released and cause mass degranulation, vasodilation and neutrophils
What is irritant contact dermatitis
Skin is injured by friction, environmental factors such as cold, over-exposure to water, chemicals and detergents and solvents
What are common ways of getting irritant contact dermatitis
hand washing
Which occupations are at risk of irritant contact dermatitis
Occupations where hand washing is frequent:
Hairdressers
NHS staff
cleaners
What is the test for allergic contact dermatitis
patch testing :
type 1 hypersensitivity - few minutes to hours for a reaction due to it being regulated by IgE so finger prick can be used
Type 4 hypersensitivity which is what allergic contact dermatitis is takes 2-3 days so patch testing over a week has to be done
What is seborrhoeic dermatitis in infants
In infants under 6 months commonly - predilection for scalp, flexures, eyebrows and nasolabral folds - severe dandruff can be seen
It appears as yellow greasy crust on top of scalp commonly known as cradle cap in infants
How do the patients with sebarrhoeic dermatitis present
The kids are quite happy and unbothered by the seborrhoeich dermatitis
What is seborrhoeic dermatitis in adults
Chronic dermatitis in adults
How does seborrhoeic dermatitis present
more malassezia yeast in the epidermis of dandruff and seborrhoeic dermatitis
red sharply marginated lesions covered in greasy scales
Areas rich in sebaceous glands are affected - face, scalp and upper trunk
yellow greasy crust on the scalp - cradle cap - seen in infants - seborrhoea dermatitis is also known as dandruff in adults
Who is more likely of developing adult seborrhoeic eczema
People with neurological disorders
What is a usual precursor for seborrhoeic eczema
dandruff
What is the treatment of seborrhoeic eczema
topical anti-yeast - ketoconazole - if dandruff, use shampoo
If it is severe and unresponsive to treatment do a HIV test
What is discoid eczema
Circular plaques of eczema which develops at irritation or trauma sites
Common in middle aged men
What is presentation of vesicular eczema
Intensely itchy
Palms and soles affected
under 40 is more common
Resolution requires desquamation - outer layer of skin is shed
What is the presentation of asteatotic eczema
very dry skin at and scaly appearance
Shins are commonly affected
What is venous eczema
Venoud drainage in the legs get worse as we age which leads to increased venous pressure and inflammation
there is pooling of the blood in the legs and due to the iron in the blood, colour change of the skin can also occur
What is the presentation of venous eczema
stasis eczema or varicose eczema
increased venous pressure
oedema
ankle and lower leg involved
What is the presentation of eczema herpeticum
Disseminated viral infection
fever and unwell
itchy clusters of blisters and erosions
swollen lymph glands
What causes eczema herpeticum
Herpes simplex 1 or 2
What is the treatment of eczema
emollients
ointments - greasy but effective
creams - lighter
lotions - more watery
Topical steroids -
hydrocortisone - if mild dermatitis
Betamethasone - used in hands and feet where skin is thick
Antihistamines - short term use
Calcineurin inhibitors - topical pimecolimus and tacrolimus - steroid free and long term use is indicated
What is the treatment of severe eczema
UV light - immunosuppressant
Immunosuppressant - cyclosporin first line but if need long term use, methotrexate is given
Biologics - dupilumab but side effects in the eyes
What is a side effect of high potent steroids
striae
What is the simple meaning of eczema
barrier dysfunction and inflammatory response
