What is a multiple sclerosis (MS) flare?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: February 11, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

A multiple sclerosis (MS) flare, also known as an exacerbation or relapse, is a period of neurological disturbance lasting at least 24 hours.

Key Characteristics of an MS Flare

  • Lasts for at least 24 hours 1
  • Characterized by inflammatory and demyelinating lesions 1
  • Requires expert clinical assessment to distinguish from pseudoattacks caused by other factors such as changes in core body temperature or infection 1
  • Objective clinical findings are necessary to confirm a diagnosis of MS, although subjective reports from the patient can raise suspicion of an attack 1
  • Single paroxysmal episodes, such as a tonic spasm, do not constitute a relapse, but multiple episodes occurring over at least 24 hours do 1

From the Research

Definition of a Multiple Sclerosis (MS) Flare

A multiple sclerosis (MS) flare, also known as a relapse or exacerbation, is a period of time when MS symptoms worsen or new symptoms appear 2, 3, 4.

Characteristics of an MS Flare

  • MS flares are characterized by an increase in disease activity, leading to a worsening of symptoms such as optic neuritis, brainstem syndromes, or long tract signs 2, 3.
  • Flares can be triggered by various factors, including infections, stress, or other environmental factors 5.
  • The severity and duration of MS flares can vary significantly from person to person 3, 4.

Treatment of MS Flares

  • Corticosteroid therapy, such as high-dose methylprednisolone, is commonly used to treat MS flares and speed up recovery 2, 6.
  • Disease-modifying therapies (DMTs) can help reduce the frequency and severity of MS flares, but may not completely eliminate them 3, 4.
  • Management of MS flares in the emergency department (ED) involves diagnostic testing, such as imaging and lumbar puncture, to confirm the diagnosis and rule out other conditions 2.

Importance of Accurate Diagnosis and Treatment

  • Accurate diagnosis and treatment of MS flares are crucial to prevent long-term disability and improve quality of life for individuals with MS 2, 3, 4.
  • Failure to diagnose and treat MS flares promptly can lead to increased morbidity and worsening of symptoms 2.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Multiple Sclerosis: An Emergency Medicine-Focused Narrative Review.

The Journal of emergency medicine, 2024

Research

Reviewing the Unmet Needs of Patients with Multiple Sclerosis.

American health & drug benefits, 2015

Research

Multiple sclerosis - etiology and diagnostic potential.

Postepy higieny i medycyny doswiadczalnej (Online), 2017

Research

Corticosteroids in the treatment of multiple sclerosis.

Acta neurologica Scandinavica. Supplementum, 2009

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.