Calculating the 7-Day Urticaria Activity Score (UAS7)

Introduction to UAS7

The UAS7 is calculated by having patients score both wheal count and pruritus intensity once daily for 7 consecutive days, then summing all 14 individual scores to yield a total score ranging from 0 to 42 points, as recommended by the Journal of Allergy and Clinical Immunology 1, 2

Patients assign a wheal score (0-3 points daily) based on the number of wheals present during the worst 24-hour period, with 0 points indicating no wheals, 1 point indicating mild (<20 wheals per 24 hours), 2 points indicating moderate (20-50 wheals per 24 hours), and 3 points indicating intense (>50 wheals per 24 hours or large confluent areas) 1
Patients assign a pruritus score (0-3 points daily) based on the overall severity of pruritus for that day, with 0 points indicating none, 1 point indicating mild, 2 points indicating moderate, and 3 points indicating intense 1

The UAS7 is calculated by summing the daily scores (wheal + pruritus) across all 7 days to obtain the UAS7, with a maximum possible score of 42 points, as recommended by the Journal of Allergy and Clinical Immunology 1, 2

The UAS7 should be used at baseline and every follow-up visit to assess disease activity and guide treatment decisions, with a minimal important difference (MID) of approximately 10-12 points, as recommended by the Journal of Allergy and Clinical Immunology 2
Patients must complete the diary prospectively for 7 consecutive days rather than retrospectively, as recall bias significantly reduces accuracy, as noted by the Journal of Allergy and Clinical Immunology 2

The American Academy of Allergy, Asthma, and Immunology recommends using the UAS7 as the standard tool for assessing disease activity in CSU patients with wheals, with a scoring system that includes wheal scores of 0-3 based on count and pruritus scores of 0-3 based on severity 3
The Urticaria Control Test (UCT) assesses disease control with a cutoff of ≥12 points indicating well-controlled disease, and should be used to guide treatment escalation decisions, as recommended by the American Academy of Allergy, Asthma, and Immunology 3

The UAS7 demonstrates strong psychometric properties, including high correlation to physician global assessments and quality of life measures, validating that patients can reliably assess their own disease activity, with a minimal important difference (MID) of 10-12 points 3
The Angioedema Activity Score and Angioedema Control Test (AECT) should be used in combination with the UAS7 for patients with angioedema, as recommended by the American Academy of Allergy, Asthma, and Immunology 3