Type IV Hypersensitivity and the Skin

Question 1

describe what type IV hypersensitivity reactions are

Answer 1

delayed hypersensitivity, antigen specific, T cell mediated, onset typically 24-48 hours after exposure

Question 2

what are type IV hypersensitivity reactions that occur at the skin called

Answer 2

allergic contact dermatitis

Question 3

what types allergens can cause type IV hypersensitivity reactions at the skin

Answer 3

direct skin contact, airborne contact, injection

Question 4

give some examples of direct skin contact causes of type IV hypersensitivity reactions

Answer 4

nickel belt buckle, Thiuram/Rubber in gloves, Colophony in elastoplast, Chromate in leather sandal, Garlic

Question 5

give some examples of possible iatrogenic type IV hypersensitivity skin reaction

Answer 5

diethylthiourea(in Neoprene wrist splint), dermabond surgical glue

Question 6

what can cause of lichenoid type IV hypersensitivity reaction

Answer 6

gold crowns

Question 7

give an example of an airborne skin type IV hypersensitivity reaction

Answer 7

fragrance in deodorants

Question 8

give an example of an injection skin type IV hypersensitivity reaction

Answer 8

PPD in black henna tattoo

Question 9

what investigation is used for type IV hypersensitivity reaction

Answer 9

patch testing

Question 10

what is used in the general management of type IV hypersensitivity reactions of the skin

Answer 10

allergen avoidance/minimisation, emollients, topical steroids, UV phototherapy, immunosuppressants