Multiple Sclerosis 101: Relapses

Last updated: July 2022

Relapses, exacerbations, flares, attacks...they go by many names, but they all mean the same thing - the immune system is actively attacking myelinated nerves in the brain and spinal cord. Even though it seems like it should be easy to tell if you are having a relapse or not, most people with RRMS have experienced something that makes them wonder “am I relapsing?” or "is this a MS symptom?". When I was first diagnosed, I think someone forgot to tell me that remission means something totally different then the image of remission that I had in my head. Even in remission, we struggle with symptoms left behind by lesions from relapses. Furthermore, determining whether a symptom is a relapse, pseudo-exacerbation, or something else altogether can be difficult. I hope to clarify some things for you today!

What is a relapse?

The MS Society defines a relapse as any new or worsening symptom that lasts for more than 24 hours, happens more than 30 days after a previous attack, and that occurs in the absence of another cause such as stress, infection, or an elevation in body temperature.1

In addition to a relapse, external factors like stress, illness, or temperature changes can cause a sudden worsening of symptoms (or pseudo-exacerbation). This is why it’s important to avoid extreme temperatures, stress (when possible!), and aggressively treat fevers. However, anytime you have a new or worsening symptom that persists for 24 hours or more you should give your doctor a call and let them decide if it could be a relapse or not. For example, when symptoms of a relapse emerge, many doctors will have you give a urine specimen to test for a urinary tract infection (UTI), because UTI's can mimic symptoms of a relapse and are common in people with MS. It’s important to determine the cause of symptoms, because the treatment of an infection is very different than the treatment for a MS relapse.

Using an MRI to further evaluate

To further evaluate new symptoms, your doctor may order an MRI scan. During a relapse sometimes we are able to identify where in the central nervous system damage is occurring. This shows up as “enhancing lesions”, or lesions that light up brightly when contrast dye is given. These look different then old lesions, which do not react to dye. However, MRI images are not perfect and sometimes the pictures do not match the clinical exam (which is frustrating!). Therefore, you can’t conclusively rule out a relapse just because the MRI didn’t show any enhancing lesions. If your doctor determines that you are having a relapse, they will discuss options such as steroids or Acthar Gel.

There is no cure for relapses

Lets stop and clear up one very common misconception: there is no cure for relapses, only treatment. Steroids and Acthar Gel do not stop a relapse, or even minimize damage, but they do speed up recovery time. You will recover from a relapse to the same degree with or without medication. With medication, the average recovery from a relapse is two weeks faster than without them. If a relapse is mild, meaning that symptoms are tolerable and don't interfere with daily activities too much, then treatment may not be necessary. For mild relapses, the side effects of the treatment may not outweigh the benefits of taking it, and that is a decision you and your provider can make together.

Lets talk about the treatment options a little bit


Most often steroids for relapses are given intravenously (IV), but they can also be given by mouth (PO). IV steroids are preferable because the dosage that is given to treat an MS relapse is HUGE. This high dosage is extremely hard on the stomach, and most people are unable to tolerate it by mouth without developing an ulcer. Those of us who have had IV steroids can even confirm that the gastrointestinal side effects are no joke, even when you aren’t even swallowing them. The most common side effects of steroid treatments are gastrointestinal symptoms (diarrhea, nausea, abdominal pain), night sweats, and insomnia. IV steroids can be given for 3 or 5 consecutive days in the hospital as an inpatient, in an infusion center, or at home. Once the round of steroids is done they will stay in the body and continue to work for up to a month, which is why you may not feel the full effects for a couple of weeks.

Acthar Gel

This is an alternative relapse treatment for those who are allergic to/cannot tolerate steroids, individuals who don’t respond well to steroids, and for individuals with bad veins who have difficulty with IV access. Acthar Gel is self-injected, and the dose/schedule can vary. Side effects include GI symptoms (changes in appetite, nausea, vomiting, diarrhea, constipation), insomnia, and sweating. It can also be challenging to get insurance companies to approve the use of Acthar Gel, but your doctor’s office will work with you and your insurance company as much as possible.

Other interventions

The central nervous system is capable of working around damage done by a relapse, but it takes time. Unfortunately, there is no way to predict how complete recovery will be, or how long it will take. In fact, it's not uncommon for recovery to take months. Interventions such as physical therapy, speech therapy, cognitive rehabilitation, and occupational therapy can help tremendously in maximizing results, so I encourage you to discuss these options with your doctor.

What to do when you just don't know

Most importantly, if you are wondering if you are relapsing or not, pick up the phone and call your nurse or provider. It can be difficult to tell the difference sometimes, so run it by us- this is what we do all day long!

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This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.

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