The Urticaria Activity Score (UAS) is a standardized questionnaire designed to measure the severity and activity of urticaria (hives) in patients. The UAS was developed in 2006 by a team of doctors led by German physician Torsten Zuberbier. It was first introduced in the EAACI/GA2LEN/EDF guideline for urticaria diagnosis, proposing a unified scoring system to facilitate the comparison of study results across different centers. Currently, urticaria activity is primarily measured through patient-reported outcome measures due to the lack of reliable diagnostic markers.

The UAS it's the most used instrument to measure urticaria, both in clinical trials and in day-to-day practice. It has been used in most clinical trials in chronic spontaneous urticaria in recent years as the main outcome parameter.

Chronic urticaria affects around 1% of the global population. Urticaria, also known as 'hives,' significantly impacts quality of life by interfering with daily activities, work productivity, sleep, and emotional well-being. The UAS is a daily questionnaire that produces a numeric score from 0 to 6, reflecting urticaria activity based on two parameters: the number of wheals (hives) and the severity of pruritus (itchiness). Since urticaria symptoms can fluctuate significantly throughout the day, the UAS provides a reliable way to assess the condition over time. The UAS allows clinicians to gauge the severity of urticaria, aiding in treatment decisions and monitoring treatment efficacy. This tool is essential for developing and evaluating new treatments for urticaria.

The UAS7 is calculated by scoring two parameters—itch severity and number of hives—on a scale from 0 to 3, daily, for 7 days. The UAS7 formula is:

UAS7 = Σ ( itch score + hives score ) over 7 days

This results in a cumulative weekly score between 0 (no activity) and 42 (maximum activity).

The Urticaria Activity Score (UAS) is calculated based on daily assessments of two key symptoms of urticaria: the number of hives (wheals) and the severity of itch (pruritus). The UAS score ranges from 0 to 6 for each day, with higher scores indicating more severe urticaria activity. Here's how to calculate the UAS:

Itchiness (Pruritus) Score:

• 0 points: None.
• 1 point: Mild (present but not annoying or troublesome).
• 2 points: Moderate (troublesome but not interfering with normal daily activity or sleep).
• 3 points: Intense (severe, interferes with normal daily activity or sleep).

Daily UAS = Hives Score + Itch Score

On this page, you will find the UAS Calculator as well as the AUAS, an advanced automatic urticaria severity assessment tool by Legit.Health that analyzes images for accurate UAS scoring.

The UAS7 is a weekly version of the UAS, calculated by summing the daily scores over seven days. This provides a score ranging from 0 to 42, with higher values indicating higher urticaria activity. The UAS7 is widely used in clinical trials as a benchmark for evaluating treatment efficacy. To calculate the UAS7 sum the daily UAS scores over seven consecutive days to obtain the weekly UAS score, known as UAS7. This score ranges from 0 to 42.

UAS7 = Σ_i=1⁷ (Hives_i + Itch_i)

The UAS7 is widely regarded as an effective tool for assessing urticaria severity in clinical settings. It allows for a standardized evaluation of symptom progression, helping clinicians adjust treatment regimens and track patient response over time.

While the UAS is widely used, it has limitations:

• Subjectivity: The score is based on patient-reported symptoms, which can vary in accuracy.
• Non-linearity: Improvements in scores may not directly correlate with disease severity or patient well-being.
• Narrow Score Range: Most patients fall within a narrow band of scores, limiting the scale's usefulness.

In 2019, a multidisciplinary team of scientists from several countries developed the Automatic Urticaria Activity Score, also called AUAS. The AUAS automatically measures how much urticaria a patient suffers from by analyzing a photo of the patient.

The main advantage of the AUAS is speed. The AUAS requires only raking a picture and checking a checkbox, while the manual UAS requires several minutes every day. The reality is that many patients do not fill in the UAS because it is tedious.

Another advantage of AUAS is the reduction in inter-observer variability. The AUAS outperforms traditional methods, achieving a margin of error below 13%, much lower than the usual 20% observed in traditional manual UAS.

The Automatic Urticaria Activity Score (AUAS) is an advanced tool designed to automate the assessment of urticaria severity using artificial intelligence (AI). Unlike the traditional Urticaria Activity Score (UAS), which relies on patient-reported outcomes and manual counting of hives, the AUAS leverages AI technology to enhance accuracy and efficiency.

Key Features of AUAS:

1. AI-Based Analysis: The AUAS uses convolutional neural networks to analyze photographs of the patient's skin. This technology allows for precise counting and classification of hives without the need for manual input.
2. High Precision: By automating the process, the AUAS reduces human error and variability. It achieves a margin of error below 13%, significantly lower than the approximately 20% error rate observed in traditional manual scoring.
3. Speed and Efficiency: The AUAS simplifies the process of daily scoring. Patients or healthcare providers can capture a photo of the affected skin area, and the AI system quickly provides an accurate Urticaria Activity Score. This reduces the time required for assessments and improves patient compliance.
4. Consistency: The automated nature of AUAS ensures consistent scoring across different users and over time, minimizing inter-observer variability that can affect manual scoring methods.

• Improved Accuracy: By removing subjective elements and manual counting, the AUAS provides a more objective and reliable measure of urticaria severity.
• Enhanced Patient Experience: The quick and non-invasive process encourages regular monitoring and reporting by patients, leading to better disease management.
• Better Clinical Outcomes: Accurate and consistent scoring helps clinicians make informed treatment decisions, monitor progress, and adjust therapies as needed.

Implementation in Dermatology:

The AUAS represents a significant advancement in dermatology, particularly in managing chronic spontaneous urticaria. It is expected to set a new standard in how urticaria is assessed and monitored, providing high-quality endpoints for evaluating treatment efficacy and improving overall patient care.

By integrating AI technology into routine clinical practice, the AUAS offers a promising future for more effective and evidence-based management of urticaria.