Immunology 5: Inflammatory dermatoses Flashcards
what are the 3 layers of skin?
epi dermis
dermis
subcutaneous tissues
hairy skin -
hair follicles
apocrine glands
describe the layout of the epidermis
- base memb
- on top = keratinocytes –> moves up as they proliferate –> form stratum cornea = important barrier function
- contains melanocytes, merle cells, langherans cells
describe how keratinocytes changes as they move upwards
- basal cells –> prickle cell –> granular cell –> (nuclei lost) –> keratin
describe the structure of the stratum corneum
contains keratinocytes
- in nbtw =glue = consisting of lipid + protein e.g filagrin –> aids integrity of stratum corneum
gene mutation in filagrin =
gene mutation in filagrin = pre disposed to be dry –> more likely to lead to eczema
what is atopy?
tendency to develop hypersensitivity
What are the 3 main atopic disease?
- eczema, asthma, hay fever
What is a key characteristic of atopic eczema?
common, relapsing, remitting
–> defecting barrier function in skin
what is the atopic march
people with atopic disease tend to develop eczema first –> sensitizes inviduals to environmental allergens (in skin) –> which then manifests as other atopic diseases e.g rhinitis, asthma etc. later on in their life
What changes when atopic eczema becomes acute –> chronic?
Th2 immune response –> becomes Th1 immune response
What are some signs of having a filagrin mutation?
- palmar hyperlinearity
Infantile atopic eczema –> e.g eczema on face –> food on face –> allergic to food later on
-
How does the pattern of atopic eczema change as they grow?
baby = back of head, arms, cheeks, below neck
adult = flexure of arms + legs, popliteal fossa, antecubital fossa
what is visual difference between acute and chronic eczema?
- acute eczema = red, weepy + sore
- chronic eczema = less red + lichenification
what is eczema herpeticum
- eczema = skin inflamed –> predisposed of herpes simplex
- -> spreads on skin surface –> presents as blisters + ulcers
what is seborrheic eczema
what is treated with
- nasal fold, scalp, eye lids
- overgrowth of yeast
treatment = topical anti fungals, topical steroids
what is allergic contact dermatitis
- allergy to specific product
e. g eye drops, makeup
-
what is discoid eczema
-disc shapes around the body
esp in elderly / those who over wash
–> topical steroid + reduce use of soap/ wash gel
What is psoriasis
- immune related
- inflammatory dermatosis
- presents w skin lesions
- plaques of skin (salmon pink)
- with silver scale
pathogenesis of psoriasis:
- genetic suspectpibility required
- env trigger e.g infection, drug, stress
- immune réponse –> psoriasis
t cells predominate in dermis –> stimulate cytokine release (TNF-a) –> neutrophils go into epidermins–> over production of keratinocytes –> causes thickening of epidermis
top layer = immature –> not lost neutrophils = scaling
red = blood vessel dilated
what would be the characteristics of a histology of psoriasis
- hyperkeratosis (thickening of outer skin layer)
- parakeratosis (retention of nuclei in stratum corneum)
- acanthosis (thickening of epidermis)
- inflammation
- dilated blood vessels
describe the distribution of skin lesion in psoriasis
- scalp
- trunk
- elbows (outside)
- knees (outside)
- groin + genitals
- armpit
- psoriasis soles (symmetrical)
–> tends occur in
what are other signs of psoriasis ?
- loss of nail cuticles
- subungal hyperkeratosis
- roughening of nails
- pitting of nails
- onycholysis
