Skin immunology Flashcards
What constitutes the skin’s main physical barrier?
The stratum corneum (keratin layer)
How do keratinocytes contribute to maintaining the barrier defence?
Can sense pathogens via surface receptors- respond to PAMPs and produce cytokines/chemokines
What are the main resident skin immune cells?
Langerhans cells
Where are most CD8 cells in the skin located?
Epidermis
What are the main roles of CD4 cells?
TH1- activate macrophage
TH2- help B cells make antibody
What kind of immune reaction is associated with a rapid wheal and flare reaction?
Type 1- IgE/mast cell mediated
What are the symptoms of allergic contact dermatitis?
Itchy red skin, oedema and vescicles at site of contact
What type of hypersensitivity is allergic contact dermatitis?
Type 4- T-cell mediated
What are the two stages of allergic contact dermatitis?
- Sensitizing phase- several sub-threshold exposures
2. Elicitation phase or symptomatic phase
What is the standard diagnostic technique for allergic contact dermatitis?
Patch testing
What is the key factor in the development of atopic eczema?
Impairment of the skin barrier allowing access to sensitizing allergens and colonisation by bacteria
What is psoriasis characterised by?
Reversible skin plaques
In what way is psoriasis an immune disease?
Chronic inflammation- environmental triggers in predisposed individuals
Stressed keratinocytes release factors stimulating interferon gamma release; leading to macrophage, T-cell and fibroblast recruitment
Name two autoimmune diseases associated with skin signs.
Vitiligo
Lupus
