Background: Dermatitis can impair the quality of life (QoL) of patients. Knowledge of the QoL‐associated factors and the impact of patch testing on QoL is limited.

Objective: To identify demographic and clinical factors affecting QoL, and to measure the impact of patch testing on QoL of dermatitis patients.

Methods: The data and Dermatology Life Quality Index (DLQI) questionnaires of 519 dermatitis patients were analyzed. Of these, 107 underwent patch testing and completed the questionnaires two times (once before testing and again 60 days afterward).

Results: The overall mean (±standard deviation) DLQI was 9.5 (±6.4). Patients aged 20 to 59 years and those who had more frequent disease exacerbations demonstrated significantly higher DLQIs. For each DLQI question, being female and aged 20 to 59 years were associated with impairments of various aspects of life, whereas the anatomical site of dermatitis impacted each question differently. The DLQI scores of the patients undergoing patch testing decreased significantly, irrespective of whether the test results were positive or negative.

Conclusions: eing of a working age and having more frequent disease exacerbations had negative QoL impacts. In addition, patch testing improved almost every aspect of the DLQI.