Inmmun 4 : Dermatoses Flashcards
Describe the microanatomy of skin
Epidermis-4 cells types-then BM
then Dermis
Then subdermis/subcutaneous tissue
epidermis, Startum conrea, papillary dermis, reticular dermis (full of collagen and fibroblasts), hypodermis
In dermis-sweat glands, sebacous glands, hair follicules
cell types: Keratynicytes, merkel cells, melanocytes, dendritic cells Keratynocytes change (flatten, and at startum granulosum-die but full of keratin. at very top-coreum-no nucleus and dead)
What are the 5 layers of the epidermis and how do keratinocytes change in them? what other cells are present
Certain legs get sun burnt
Keratynocytes change (flatten, and at startum granulosum-die but full of keratin. at very top-coreum-no nucleus and dead)
spinisum layer cell- mostly nomral looking cell
Near BM-find melanocytes, merkel cell
What happens to keratinocytes when they reach the stratum conreum
Keratynocytes flatte and lose nucleus as reach too
Between them, lipid+protein glue that stick them togethert to from the barrier
Important protein-Filagrin . If mutated, eczema
What is atopic eczema? Some exemples of causes?
Atopy-tendency to develop hypersensitivity
Eczema-relapsing skin condition-usually in babies and grow out of it but can stay, or come back later
usually caused by defects in the skin that allow Ag to enter the skin too well
like filagrin gene mutation
What is atopic march?
that particular allergies tend to happen at certain point in life and leave later
eczema-start early, peak at 2, then goes down
Food allergt-very similar.
Asthma-peak around 6y/o
Rhinitis-increase adulthood
What is plamar hyperlinearity? What is it a sign of?
Many lines on hand-early sign of filagrin gene mutation
If patient comes in itchy-maybe with rashes-look at lines to see if have them-> if with the lines, eczema can cause dry skin and the rashes+itchyness
Where are the common patterns of exczema outbreaks?
Very young-around head, but spare mouth and nose
then on elbows, knees-when wlaking
adults change a lot
What are some chronic changes eczema can bring?
Lichenification is common-not as red, scartch marks
Severe eczema-on the whole body
What are some things eczema predispose to?
Staph aureus-acts like super Ag
And herpes simplex-virus spread amongst dead/open skin
Vesicles appear, then punched out ulcers -> called eczema herpeticum (not usually that severe because not too far)
What is Seborrhoaeicc, allergic contact dermatitis, dicoid eczema?
Seborrhoeic-not atopic
Combination of specific yeast+eczema -its dandruff
usually nose, eyebrows (treat with antifungal)-comes back in stress
allergic contact dermititis-atopic eczema predisposes but not always
sensitisation to specific allergies-like cosmetics (rash around eye), hair dye, tattoo
discoid-disc like patches of eczrma-seems realted to dryness (overwashing, older adults, atopic eczema)-moisturise, avoid soap, steroids
What is psioriasis?
Plaquy red skin-clear cut off bewteen affected skin and not affected-red, scally plaques
genetic predisposition-many many genes involved (triggers-stress, alcohol, smoking, infection (strep escpecially), some medication)
Causes by overproliferation of keratynocytes-and reach the top before full maturation-shed while immature (have nucleus). Also keratinocyte go down even deeper into dermis
Hyperkeratosis, parakeratosis (nucleus at top) acanthosis (thickening of keratinocyte layer)
Cause inflammation->dilated blood vessels (redness)
What areas of the body does psorioasis affect?
Scalp, elbow, trunk, nails (debris under nail and dystrophy of nail) genitals, feet, hands
Onycholisis (more white area at tip of nail) and pitting (into) in nails–
usually quite symetrical (usually means inflammatory rather than infections)
What is guttate psoriasis? And palmoplantar pustulosis? generalised pustular psoriasis?
Pattern of psoriasis-affects teenargers and young adults
not big plaques-little papilles (2-3mm)
Each are salmon pink and scaly like plaque
often when strep infection cause it
palmoplantar-often patients only have pustules on hand and feet-not all over psorioasis-smoking, drinking
generalised pustular- need to be sure not infection or drug causes.
If psoriasis-very superficial white tiny pustules-contain nuetrophils but Sterile-no infection
Usually all over the body-and can make people feel very unwell
What is Acne?
Disorder of the hair follicule and associated cebacous glands
genetic predisposition-usually at puberty after Ag appearance
pore-build up of debris and keratine in the opening of the pore-> build up of cebum which gets colonised by Perpionibacteria acnes-then inflam, burst, and when the pus goes to skin again-re-infect
features-black heads, white heds, papulles (combination, all at the same time
treatment-lots-ladder-skin sterlisation, topical Abx (lipophilic to dissolve in cebum), contraceptive pills, other oral Abx
What is bullous phemigoid? and epidermolysis bullosa
Deeper blisters compared to pempigous
Epidermis-ectoderm, dermis-mesoderm-why basement membrane bewteen them+specialised hemidesmosomes and BPAg1/2 (attache hemidesmosome to cell)
If either proteins genetically affected OR AID targetted
Phemigoid-AID againt BP1/2 ->in targetted area, epidemis seperate from dermis-forms large blister all over body
Steroids to prevent AB formation
Can present with just redareas w/o blistering
If one of the protein actually defective-epidermolysis bullosa-splitting of the skin (ranges from severe to very midl)
