PUAs (physical urticaria/angioedema syndromes) are rather prevalent. A history of physical causes that cause cutaneous symptoms is used to identify them, and provocation testing is used to confirm their diagnosis. Although recent recommendations have advocated using challenge methods for diagnosis, their positive/negative probability ratios have not been determined. Researchers conducted a comprehensive study to assess the diagnostic usefulness of three prevalent PUAs: dermatographia (DERMATO), cholinergic urticaria (CHOL), and delayed pressure urticaria/angioedema (DPUA). They were unable to find papers with appropriate methodologic quality to calculate positive/negative probability ratios for suggested diagnostic challenges for PUAs in this investigation.

The study emphasizes the need of well-designed studies to assist clinicians in interpreting diagnostic difficulties for patients with DERMATO, CHOL, and DPUA. There is a scarcity of high-quality data to support the diagnostic usefulness of office problems for PUAs. The methacholine intradermal challenge has a low sensitivity for validating a CHOL diagnosis.

Reference:https://journals.lww.com/coallergy/Abstract/2016/10000/Diagnostic_utility_of_challenge_procedures_for.16.aspx