All About Lyme Disease Rash

The Lyme disease rash that is caused by Borrelia spirochetes is called erythema migrans. It is the most common symptom for the screening for Lyme disease as stipulated by the Infectious Diseases Society of America and Centers for Disease Control.

Erythema Migrans manifests itself as a round or oval rash that increase in size. The center of the lyme disease rash becomes reddish. The inner portions of the rash are clear. It gives the appearance of a bull’s eye rash. The appearance of the rash may vary from person to person.

It is possible for the center of the rash to be raised or eroded. A bluish red rash, resembling a bruise is also fairly common. There is also possibility of multiple rashes.

Nearly 10 percent of lyme disease rash are atypical in form. Such rashes are in danger of being ignored as they do not follow the regular pattern. In such cases, Lyme disease, too, can be struck off the list.

Most Lyme disease rashes range from five to 25 cm in diameter. It may cover an important part of the leg or torso. Multiple rashes are also possible.

Research by Dr Carmen Moreno and her colleagues at Universidad Autnoma, Madrid has been published in the Journal of the American Academy of Dermatology. Research indicates that such rashes have a similar microscopic structure:

• Histiocytes increase in number at the deeper layers of the skin. Histiocytes are phagocytic cells that affect the immune system.
• Histiocytes can form rosettes in constellations surrounded by thickened collagen fibres.
• Polymerase chain reaction biopsies from the outermost layers of the rashes indicated DNA of Borrelia. This is in sharp contrast to biopsies from the center of the rashes. Out of 11 patients, five tested positive for ELISA. The IgM and IgG ELISA were inconclusive for the remaining six.