This results from binding of the latex allergen to sensitised receptors on mast cells. There are several available. Latex is introduced into the skin in small quantities at a pinprick site. Positive results are swelling or reddening of the skin, and these can be graded according to size. Skin-prick testing is thought by some to be dangerous, particularly intradermal injection, because of the possibility of life threatening anaphylactoid reactions.
Testing has to be performed with the allergen against which the patient is allergic.
The different types of available allergen extracts may not contain the particular allergen. There are also safer in vitro tests. A blood sample is taken and tested for the presence of IgE antibodies specific to latex. There are a number of tests from different manufacturers who may use different latex extracts. Processes which link allergen proteins using amino groups give very good results compared with skin-prick testing.