Lyme Disease Bulls-eye Rash — What Is It and When Does It Appear?

May 30, 2018
bulls eye rash

The “bulls-eye” rash is a distinct pattern that appears on the skin after a person that has been bitten by a tick infected with the bacterium that causes Lyme disease, contracts Lyme disease. It is not the same as the typical small swelling or red spot that develops almost immediately after a tick, or other insect bites or stings you. Rather, the characteristic “bullseye” (also known as erythema migrans, or EM) occurs within three to 30 days after a bite from an infected tick. On average, the rash appears within one week of infection. The Centers for Disease Control and Prevention (CDC) estimates that bullseye rash affects 70% to 80% of infected patients. A patient with a rash matching this description should seek immediate attention.
Variable Size and Appearance

  • EM lesions most commonly present as a single uniform erythematous oval to circular rash ranging from 5cm to 70cm at the site of the bite.
  • About 20% of EMs have the appearance of a “bull's-eye” with a dark red center surrounding by a pale ring, followed by a reddish exterior ring.
  • Among some patients, EMrashes may actually appear in places where the patient was not bitten.
  • The rash(es) expand in size over the course of several days.
  • To monitor any changes, it may be helpful to mark the edges of the rash when it first appears using a waterproof marker.
  • It may also be helpful to take photographs, which you can share with your healthcare practitioner. Serial photographs may help document any changes or progression in the shape or size of your rash or rashes.

Flu-Like Symptoms: Seek Immediate Attention
Not all Lyme disease presents with a rash. If you develop flu-like symptoms (fever, chills, headache, body-aches) within 30 days of a tick bite, it is important to visit your primary care provider, or PhysicianOne Urgent Care for immediate medical attention, regardless of the appearance (or absence) of any rash.
Despite our best efforts, even the healthiest people get sick. If you suspect you or a loved one may have been bitten by a tick, PhysicianOne Urgent Care is here seven days a week for high-quality urgent care, at a fraction of the cost of the Emergency Room. Contact us at 1.855.349.2828, or walk in to be seen today. If you’re looking to save time, find a location near you and check in online!

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