intro to derm Flashcards
6 common problems seen in derm
- skin cancers - common cause of death in YA;
- inflammatory disorders (eczema, psoriasis etc.);
- acne;
- inherited/childhood skin disease;
- skin infections;
- pigment, hair and nails disorders
what is eczema
a term used to describe a collection of diseases that have similar presentation (itchy, dry, red) and maye co-exist with eachother - including atopic eczema (majority), allergic contact eczema, discoid, varicose eczema etc.
eczema vs dermatitis
all eczema is dermatitis (but not all dermatitis is eczema)
what is the atopic triad
asthama, eczema, allergic rhinitis (e.g. hayfever)
what are some consequences of eczema itch
loss of sleep, loss of concentration, anger, may not be able to do their job
what are Pompholyx
a type of eczema which affects the hands and feet, causing tiny blisters and irritation
erythroderma vs suberythroderma
erythroderma - greater than 90% body surface area involved
suberythroderma - 70-90% of body surface area involved
what is follicular eczema
eczema around the hair follicules
what causes the erythema in eczema
diversion of blood to skin due to inflammatory cytokines or more translucent skin -> may result in increased heat loss and increased itching
what causes scale in eczema
excessive production of epidermis which peels off or stays stuck to the top layer so become thick - hyperkeratosis
what causes lichenification in eczema
thickened hyperkaeratotic skin due to rubbing with more lines/wrinkles
functions of the skin
- thermoregulation;
- physical barrier (infection, allergens, waterproofing)
- key strucutre for body
- vit D synthesis
what is responsible for the waterproofing of the skin
oily (waxy) layer produced by seebum
where might babies present with eczema
face
what are the typical site for eczema to present
flexures - creases of arms, knees, wrists
what is a common reason for treatment failure in derm
“steroid-phobia” - many people wont use steroids as they worry about side effects
side effects of hydrocortisone
thin skin (rare)
steroid potencies + examples
- mild e.g. 1% hydrocortisone;
- medium e.g. emovate;
- potent e.g. betnovate
- very potent e.g. dermovate
what can occur if wrong potency of steroids is used
too weak - increased suffering, no treatment progression
too strong - skin thinning, possibly cushings (unlikely unless repeat of very potent steroids)
what causes asteatotic eczema
lack of oil on the skin - usually if in hosptial/nursing home
features of asteatotic eczema
cracking of skin, like a dry river bed
treatment for asteatotic eczema (3)
- bathe less often/for shorter periods of time and use cooler water;
- use less detergent;
- apply oil to skin
where does irritant contact eczema usually occur
the hands
why is history essential in diagnosing the eczema type
many eczemas look the same - may be difficult to differntiate between allergic, irritant and atopic eczema based on examination alone
irritant contact vs allergic contact eczema
irritant - arises due to chemicals that irritate skin cells;
allergic - arises due to an immune process
common causes of allergic contact eczema (6)
- nickle
- fragrances (on perfumes etc.)
- rubber accelerators
- chromate
- formaldehyde
- plants
how can allergic contact eczema be tested
patch testing
where might varicose eczema occur
on the lower legs, around varicose veins
what might cause varicose eczema
leaking of irritants from stagnant blood stuck in the veins -> likely neutrophils
treatments for varicose stasis (and thus varicose eczema) - 6
- loose weight - associated w obesity
- exercise
- elevate legs
- avoid standing/sitting for long periods
- compression bandages
- varicose vein surgery
what phsyical barrier can be implemented for eczema and when should it not be used
bandages; should not be used if eczema is infected
what bacteria commonly causes infection in eczema (post sractching)
staph aureus
presentation of staph infected eczema
yellow/golden crusts or blisters of impetigo
treatment for herpes simplex eczema infection
aciclovir
how to distinguish discoid eczema from psoriasis
has vesicles and lacks psoriasis scale
what casues discoid eczema and how is it treated
caused by bacterial infection of eczema; treated w Abx or antiseptic/steroid combinations
what causes seborrhoeic eczema and what area is is commonly seen in
sensitivity to yeast on skin (not in diet); commonly seen around nose, eyebrows, flexures
how to treat seborrhoeic dermatitis
topical antifungals
what should be considered (to test for) if someone presents with severe sebborhoeic dermatitis
HIV
what non-topical treatments can be offered for eczema (treatments not working)
- local PUVA - UVA phototherapy (psorellan), usually just hands of feet;
- oral alitretinoin (retinoid);
- oral azathioprine, ciclosporin (broad spectrum immunosupression)
differentials for eczema (5)
- scabies - check if family/close contacts present with the same symptoms
- fungal infection of hands - usually unilateral
- psoriasis - likely to have nail changes, not usually itchy
- drug eruption
- rarer diseases e.g. mycosis fungoides
Fitzpatrick skin types (6)
I Pale white skin, blue/green eyes, blond/red hair -Always burns, does not tan
II Fair skin, blue eyes - Burns easily, tans poorly
III Darker white skin - Tans after initial burn
IV Light brown skin - Burns minimally, tans easily
V Brown skin - Rarely burns, tans darkly easily
VI Dark brown or black skin - Never burns, always tans darkly
