Atopic disease Flashcards
What kind of reaction is allergic contact dermatitis?
Type IV (delayed hypersensitivity) reaction. An antigen such as nickel in encountered in the skin and is taken by langerhans cells to local lymoh nodes which triggers the production of T cells primed to react against the antigen on subsequent exposure, leading to the release of inflammatory mediators.
Name a mild steroid
Hydrocortisone
Name 2 moderate steroids
Betamethasone (Betnovate)
Clobetasone butyrate (Eumovate)
Name 2 potent steroids
Flucitasone propionate (Cutivate)
Betamethasone valerate (Betnovate)
Name a very potent steroid
Clobetasol propionate (Dermovate)
When would you use a skin prick test?
Food allergies and pollen
Describe a skin prick test
Drops of diluted allergens are places on skin after it has been pierces by a needle. Also includes a histamine (positive) and sterile water (negative) control. A wheal will develop if patients have an allergy and can be interpreted after 15 minutes
When is skin patch testing used?
Contact dermatitis
What is the RAST test?
Determines the amoun of IgE that reacts specifically with known allergens for example IgE to egg protein. This is used in food allergies, inhaled allergens and wasp/bee venom
After potent steroids what is the next step in atopic excema?
Calcineurin inhibitors (tacrolimus ointment)
Bandages
Phototherapy
Which antibody is high in excema?
IgE
What type of hypersensitivity is excema?
Type IV
How many grams is 1 fingertip unit?
0.5g - covers two hand areas
What do you do if you are in the GP and someone presents with eczema herpeticum?
Emergency referall and immediate oral or Iv aciclovir
