Proficiency testing of skin prick testers as part of a quality assurance system.

Background: Skin prick test is an important diagnostic procedure in clinical allergy but documentation of the quality is often missing.

Methods: We describe a proficiency system to evaluate staff members in relation to the international recommended reproducibility in terms of coefficient of variation (CV < 40 %) and the linearity (coefficient of regression >0.85) based on blinded octuplicate histamine testing using histamine 3, 10, 30 and 100 mg/ml.