The nurse knows that the diagnosis of contact latex allergy is based on history and ____.
Correct Answer: C
Rationale: The diagnosis of contact latex allergy is primarily based on the patient's history of exposure to latex-containing products and the development of symptoms upon contact with latex. To confirm the diagnosis, skin patch testing is performed. Skin patch testing exposes the skin to small amounts of latex allergens to observe for any localized allergic reaction, such as redness, swelling, or itchiness. This test helps determine if the individual has developed a delayed-type hypersensitivity reaction to latex. Latex-specific IgE testing (choice A) and finding IgE in serum (choice B) are methods used in diagnosing immediate-type latex allergy but are not sufficient for confirming contact latex allergy specifically. ELISA (choice D) is a type of laboratory technique used for various purposes, including measuring the levels of specific substances in the blood, but it is not typically used as a diagnostic tool for contact latex allergy.