Relapses, also referred to as exacerbations, attacks, flare-ups, episodes, or bouts, are initially experienced by most people diagnosed with multiple sclerosis (MS). When someone experiences a relapse, he or she may be having new symptoms or an increase in existing symptoms. Relapses occur with relapsing-remitting, progressive-relapsing, and sometimes secondary-progressive forms of MS. Relapses do not occur with primary-progressive MS, although patients may experience day-to-day fluctuations in how they feel.

During a relapse, inflammation is occurring along the nerves and the myelin, causing patients to have a temporary worsening or recurrence of existing symptoms and/or the appearance of new symptoms. This can range from a few days in duration to a few months, followed by a complete or partial recovery (remission). Acute physical symptoms and neurological signs must be present for at least 24 to 48 hours, without any signs of infection or fever, before the treating physician may consider this type of flare-up to be a true relapse.

It is important to know that occasionally symptoms are not caused by new damage and can be sometimes called pseudoexacerbations. A pseudoexacerbation is a temporary worsening of symptoms without actual myelin inflammation or damage, brought on by other influences. These can include other illnesses or infection, exercise, a warm environment, depression, exhaustion, and stress. When symptoms flare, checking for a fever is important, since even a minor infection and slight increase in temperature can cause symptoms to appear.

Urinary tract infection (UTI) is the most common type of infection to cause a pseudoexacerbation. Additionally, people with “heat-sensitive” MS will experience a temporary increase in symptoms when their body temperature rises, often after exercise. Many heat-sensitive individuals may opt to avoid hot tubs, saunas, or other situations that can raise the body’s temperature. Using cooling vests and other type of cooling apparel or devices, is often helpful for people with heat-sensitive MS to keep their body temperature down while in a warm environment.

To help individuals with MS who are heat-sensitive, MSAA has a Cooling Equipment Distribution Program (found under “How MSAA Can Help” on MSAA’s website). This program offers a cooling vest and other types of cooling accessories to help someone stay cool in warmer environments, such as when participating in outdoor activities. For individuals who qualify, MSAA provides these products free of charge (certain limitations apply).