Purpose of review Contach dermatitis is a common disease process that include allergic and irritant contach dermatitis. The gold standard for diagnosing allergic contach dermatitis, a type IV delayed hypersensitivity reaction, is patch testing. Patch testing in not a difficult procedure, however, there are several critical components that determine the success of the test.: having an appropriate level of suspicion for the diagnosis of allergic contach dermatitis, an adequate threshold for patch testing, the ncessary experience to properly interpret the resuls and to determine theier relevance, and tha ability to thoroughly educate the patient about the condition. Recent findings Research shows that patch testing practices differ among individuals and specialties. The level of patch testing education, interest in, and experience with, the procedure can affect the results fo the test. Some ot these practice differences and how they affect the outcome of patch testing are highlighted. Summary Physicians's knowledge and experience with patch testing, thier level of interest and access to allergens will determine the performance of this test, the reliability of the results and the benefits gained from this procedure.