Ask the Experts Series

In an effort to assist health care professionals and patients, the Ask The Expert Series has been launched. The questions posed to the volunteer experts who are familiar with diagnosing and treating Lyme and tick borne diseases are somewhat unusual and not easily or readily diagnosed or treated by the majority of health care professionals.

This is simply a learning tool that hopefully will help those who treat patients and those who are suffering. This is not to be considered medical advise. If you have any health care concerns please contact your own health care professional and/or pharmacist for answers.

1. Bartonella- Hand Pain

2. Rash- Unidentified, Itchy, Widespread

3. Testing Infants For Congenital Transmission of Lyme

What Does The Science Say?

A. Must A Rash Expand To Be A Lyme Rash?

B. Will Tremor Go Away With Treatment?

How Many People Get A Rash?

Typically less than 50% of people with Lyme have a rash. In children it is reported to be less than 10% (Dr. Charles R. Jones, CT.). The EM rash is diagnostic for Lyme and so it is frequently reported at high levels (sample bias). Some papers that may not have this bias are:

In 1977 Steere said 25% of patients had an EM rash.

Steere AC, Malawista SE, Snydman DR, Shope RE, Andiman WA, Ross MR, et al. Lyme arthritis: an epidemic of oligoarticular arthritis in children and adults in three connecticut communities. Arthritis Rheum. 1977;20: 7–17.


Here are some other papers

EM rash 22% mean of 2 samples Ljøstad U, Skogvoll E, Eikeland R, Midgard R, Skarpaas T, Berg A, et al. oral doxycycline versus intravenous ceftriaxone for European Lyme neuroborreliosis: a multicentre, non-inferiority, double-blind, randomised trial. In: The Lancet [Internet]. Aug 2008 [cited 3 Dec 2014] pp. 1–4. doi:10.1016/S1474-4422(08)70119-4

EM rash 26.6% Guerrero A, Escudero R, Martí-Belda P, Quereda C. Frequency of the clinical manifestations of Lyme borreliosis in Spain. Enferm Infecc Microbiol Clin. 1996;14: 72–9. Available:

EM rash 9% Djukic M, Schmidt-Samoa C, Nau R, von Steinbüchel N, Eiffert H, Schmidt H. The diagnostic spectrum in patients with suspected chronic Lyme neuroborreliosis - the experience from one year of a university hospital’s Lyme neuroborreliosis outpatients clinic. Eur J Neurol. 2011;18: 547–55. doi:10.1111/j.1468-1331.2010.03229.x

Average of studies is 43%, but as mentioned it is probably biased.

Information kindly provided by Michael Cook.

Last Updated- April 2019

Lucy Barnes


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