According to ILADS, less than 50% of those infected with Lyme disease get an erythema migrans, or bullseye rash. However, the presence of a bullseye rash indicates early infection with the bacteria that cause Lyme disease, Borrelia burgdorferi. Even by the strict CDC guidelines for diagnosis, the bullseye rash warrants “an instant diagnosis of Lyme disease and immediate treatment without further testing.” This means that if you do have a bullseye rash, you should go to a doctor as soon as possible to begin antibiotic therapy for Lyme disease. Keep a journal of any signs and symptoms you may notice.
The rash may occur up to 30 days after the tick bite and anywhere on the body, not just where the bite was. I have also heard reports of people having bullseye rashes from other bug bites, not just from a tick: mosquito, bedbug, biting fly, spider, flea, mite, and gnat.
This may be disputed by some doctors, but over 50% of those infected do not find a tick, however, if you do, be sure and keep it so it can be tested by a laboratory. I did not find the poppyseed-sized nymph tick that reinfected me last September, but I started to show symptoms of early infection almost immediately- swollen lymph glands, headache, fever, painful joints and flu-like symptoms. After being bitten, it takes at least 5 weeks for the body to produce enough antibodies to show up in a blood test for Lyme disease, although many doctors do not know this and test right away. If you have a bullseye rash, the best thing to do is to find a Lyme-Literate Medical Doctor who knows how to properly test and diagnose Lyme disease so you can treat it early, before the Bb bacteria burrow deep into the body and become a chronic, persistent infection. If Lyme disease becomes late-stage, it is difficult to treat.
Other rashes other than bullseye have also been reported in connection with Lyme disease, and over 50% of those infected do not manifest any kind of rash, so it is important to know the symptoms of EARLY Lyme infection: meningitis (headaches, neck stiffness, sensitivity to light), migrating muscle and joint pain, mood and sleep disturbances, memory loss, dizziness, heart palpitations, facial palsy (loss of muscle tone on one or both sides of the face), fever, flu- or mono-like symptoms, shooting pains and strange skin sensations.
According to the Canadian Lyme Disease Foundation the rash (if present) can vary in size and appearance, be a bullseye or generalized, and there may be one or many at any location on the body. This makes diagnosis by EM even more difficult for a practitioner who does not have specialized training in Lyme disease and related tick-borne diseases (TBDs), making it even more important to find an LLMD so you can get proper diagnosis and treatment during the early stages of the disease. The rash caused by ringworm can sometimes be mistaken for the erythema migrans, so please consult a doctor to verify.
Ringworm (pictured above) is caused by a fungus and can sometimes be mistaken for the bullseye rash, erythema migrans, that is a sign of early localized Lyme disease infection.