Erythema migrans

File:Bullseye rash linked to Lyme disease.jpg

Bullseye rash linked to Lyme disease

Erythema migrans is a distinctive skin rash typically associated with Lyme disease, a bacterial illness caused by Borrelia burgdorferi. Often referred to as a "bull's-eye" rash due to its unique appearance, erythema migrans serves as a crucial early diagnostic sign of Lyme disease.

Erythema migrans

File:Atypical erythema migrans 1 week after initial presentation.jpg

Atypical erythema migrans 1 week after initial presentation

Clinical Presentation

Erythema migrans rash usually manifests within 3 to 30 days after a tick bite, the primary vector of Borrelia burgdorferi. The rash begins at the site of the tick bite and expands over time, forming a circular or oval pattern. The center of the rash may clear as it enlarges, creating the characteristic "bull's-eye" pattern, although this is not always the case.

Diagnosis and Significance

The presence of erythema migrans in a person with potential tick exposure is highly suggestive of Lyme disease. Diagnosis is typically clinical, based on the characteristic appearance of the rash and patient history. Additional testing, such as serologic testing for Lyme disease, may be utilized if the presentation is unclear.

Treatment and Prognosis

Early treatment of Lyme disease with appropriate antibiotic therapy, such as doxycycline or amoxicillin, usually results in prompt resolution of the rash and prevents progression of the disease. Delayed or inadequate treatment may result in more serious manifestations of Lyme disease, including neurological or cardiac complications.

References

1. "Erythema Migrans." American Osteopathic College of Dermatology (AOCD). Link
2. Wormser GP, Dattwyler RJ, Shapiro ED, et al. (2006). "The clinical assessment, treatment, and prevention of Lyme disease, human granulocytic anaplasmosis, and babesiosis: clinical practice guidelines by the Infectious Diseases Society of America." Clin Infect Dis. 43(9):1089-1134. Link
3. Maraspin V, Lotric-Furlan S, Strle F. (2019). "Erythema migrans." In: Lyme Borreliosis. Springer, Cham. Link
4. Steere AC, Malawista SE, Snydman DR, et al. (1977). "Lyme arthritis: an epidemic of oligoarticular arthritis in children and adults in three Connecticut communities." Arthritis Rheum. 20(1):7-17. Link