psoriasis Flashcards
What is psoriasis
Chronic immune mediated disease which presents as a sharply demarcated erythematous plaque with silver lining
Who is more commonly affected by psoriasis
M=F
20-30 and 50-60 Year olds but most common below 40
What gene does psoriasis link to
HLA- CW6
HLA - help differentiate between self and non self
What happens in psoriasis
There are stressed keratinocytes
There is activation of dermal dendritic cells which go to lymph nodes and present uncertain antigens to naive T cells which differentiate into T helper cells which send a message to keratinocytes to proliferate and produce more keratinocytes at a higher rate which leads to plaque formation
What are the molecules that stimulate keratinocytes to proliferate
TNF alpha and interleukins
What is the function of VEGF in psoriasis - vascular endothelial growth factor
Causes angiogenesis - production of new blood vessels which vascularises the plaques and makes them very red and painful
What is the presentation of psoriasis
Sharply demarcated and eryhematous plaques - small and widely spread -covered in a silver lining
Erythroderma - have a fever and the plaques are covering more than 90% of the body
Onchyolysis - nail is coming away
pitting of the nails
oil spots of the nail - changes of colour
What is guttate psoriasis
psoriasis triggered by bacterial or viral infections
What is different about flexural psoriasis
No scales due to the friction in the areas
How is psoriasis diagnosed
clinically or skin biopsy
What are the treatments of psoriasis
Emollients most commonly
Vit D3 analogues - inhibit epidermal proliferation
Topical steroids
salicylic acid
Methotrexate - long term use
ciclosporin - fast acting but harmful to the kidney
Otelza - modulates immune system
Anti-TNF alpha drugs - infliximab and adalimumab - TNF alpha plays big role in proliferation of keratinocytes so Anti TNF alpha drugs are very effective
When are oral retinoids used in psoriasis
Older patients who do not want to be pregnant as it is a teratogen
What is the treatment of erythrodermic psoriasis
fluid balance
bloods/iv
Thick greasy ointment emollients
