Glossary
Herxheimer Reaction
A temporary worsening of symptoms that can occur when starting antibiotic treatment for Lyme disease, caused by the die-off of bacteria.
The Herxheimer reaction (also called a Jarisch-Herxheimer reaction, or informally a 'Herx') is a temporary intensification of symptoms that can occur when antibiotics begin killing Lyme bacteria. As bacteria die off, they release toxins and trigger an inflammatory response.
Symptoms of a Herxheimer reaction can include increased fatigue, flu-like symptoms, increased pain, sweating, chills, and cognitive symptoms. The reaction is typically short-lived, lasting from hours to a few days.
Many Lyme-experienced practitioners interpret a Herxheimer reaction as confirmation that treatment is reaching active bacteria. However, patients should always discuss new or worsening symptoms with their provider to rule out other causes.
Symptoms of a Herxheimer reaction can include increased fatigue, flu-like symptoms, increased pain, sweating, chills, and cognitive symptoms. The reaction is typically short-lived, lasting from hours to a few days.
Many Lyme-experienced practitioners interpret a Herxheimer reaction as confirmation that treatment is reaching active bacteria. However, patients should always discuss new or worsening symptoms with their provider to rule out other causes.
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