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What is a flare?

Lupus Foundation of America

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A flare is defined as: 

A measurable increase in disease activity in one or more organ systems involving new or worse clinical signs and symptoms and/or lab measurements. The increase must be considered clinically significant by the assessor (physician or clinical researcher), and in most cases should prompt the consideration of a change or an increase in treatment.


Until recently there was no community-wide agreement on how to define clinical flares in lupus patients. Various clinical trials have used different definitions of flare, making it hard to compare results or interpret outcomes.

In 2005, the U.S. Food and Drug Administration (FDA) identified the need for a consistent definition of a lupus flare to enable more precise outcome measures for research studies, such as the number of flares or the time between flares. 

The Lupus Foundation of America responded by spearheading a four-year, worldwide initiative to develop the very first universally accepted definition of a lupus flare. Published in 2010, the consensus definition of a lupus flare facilitates new drug development and helps physicians characterize lupus with standard, agreed-upon language.

Is it normal fatigue or a lupus flare: learn the difference

It is normal to be tired at the end of the day, especially if you have been physically active. If you have lupus and your work or home life requires high levels of energy, it is normal to feel exhausted. Not every bout of fatigue is a lupus flare. The best way to determine whether or not you are having a flare is to learn about the symptoms and triggers, track them carefully, and keep the lines of communication open between you and your doctor.