Diagnosis is by patch testing, a method first used in 1895. Patches containing potential allergens are stuck on the skin, and the skin is monitored for inflammation. For<unk> ns, patch test reproducibility is low, and the extent to which they predict implant failures is debated. If the person being tested has a rash already, it may be difficult to do a patch test. Patch testing may also worsen the allergy. it is also difficult to distinguish co-sensitivity from cross-sensitivity using a patch test. In-vitro tests, where a blood sample is examined for<unk> -sensitive T cells, are in development, but not widely used, partly due to cost. Many non-allergic people also have<unk> -specific T cells, and in some cases they seem to have more than some allergic individuals, which makes the test less useful.
Metal allergy
Nickel allergy
Food allergy
Sesame allergy
Dust mite allergy
Drug allergy
Animal allergy
Garlic allergy