Method for Grading Urticaria Activity Using the UAS7 Tool
The UAS7 (7-Day Urticaria Activity Score) tool measures urticaria activity by assessing both wheal count and pruritus severity daily for 7 consecutive days, with scores ranging from 0-42 points, providing an objective measure of disease severity and treatment response. 1
UAS7 Scoring System
The UAS7 consists of two components scored daily for 7 consecutive days:
1. Wheal (Hive) Score (0-3 points daily)
- 0 points: None (no wheals)
- 1 point: Mild (<20 wheals per 24 hours)
- 2 points: Moderate (20-50 wheals per 24 hours)
- 3 points: Intense (>50 wheals per 24 hours or large confluent areas of wheals)
2. Pruritus (Itch) Score (0-3 points daily)
- 0 points: None (no itch)
- 1 point: Mild (present but not annoying or troublesome)
- 2 points: Moderate (troublesome but does not interfere with normal daily activity or sleep)
- 3 points: Intense (severe pruritus that interferes with normal daily activity or sleep)
Daily and Weekly Calculation
- Each day, add the wheal score (0-3) and pruritus score (0-3) for a daily total of 0-6 points
- Sum the seven daily scores for a weekly UAS7 score ranging from 0-42 points
UAS7 Disease Activity Categories
The total UAS7 score corresponds to disease severity categories:
- 0 points: Urticaria-free
- 1-6 points: Well-controlled urticaria
- 7-15 points: Mild urticaria
- 16-27 points: Moderate urticaria
- 28-42 points: Severe urticaria 2
Implementation in Clinical Practice
Documentation Options
Two validated versions of the UAS7 exist:
- Standard UAS7 (recommended): Once-daily documentation of symptoms 1, 3
- UAS7TD: Twice-daily documentation (morning and evening) 4
Research shows both versions yield comparable results (correlation coefficient 0.90-0.95), with the once-daily version being less burdensome for patients while maintaining accuracy 5, 3.
Clinical Interpretation
- Minimal Important Difference (MID): A change of 11 points in the UAS7 represents a clinically meaningful improvement 4
- Smallest Detectable Change (SDC): 12 points for the standard UAS7 4
Practical Application
- Provide patients with a 7-day diary to record daily wheal count and pruritus severity
- Instruct patients to score both components at approximately the same time each day
- Calculate the UAS7 score at follow-up visits by summing all 14 values (7 days × 2 components)
- Use the score to guide treatment decisions based on disease activity categories
Clinical Utility
The UAS7 is valuable for:
- Objectively assessing disease severity
- Monitoring treatment response over time
- Standardizing assessment across different clinical settings
- Guiding treatment decisions based on validated disease activity categories
The UAS7 should be used alongside other validated tools like the Urticaria Control Test (UCT) for comprehensive disease monitoring, as recommended by international guidelines 1, 6.