Comparison of Lyme Disease in the United States and Europe

Adriana R. Marques; Franc Strle; Gary P. Wormser


Emerging Infectious Diseases. 2021;27(8):2017-2024. 

In This Article

Erythema Migrans and Other Skin Manifestations

After Lyme borrelia are deposited in the skin by the bite of an infected Ixodes tick, an infection is typically established at that site, which causes the characteristic skin lesion, erythema migrans (Figure 1). Erythema migrans is the most common clinical manifestation of Lyme disease in the United States and Europe, occurring in ≥80% of patients in both geographic areas.[2] Overall, US patients with erythema migrans caused by B. burgdorferi s.s. are less likely than patients in Europe with erythema migrans caused by B. afzelii or B. garinii to remember a tick bite at the site of the lesion (25% vs. 60% for B. afzelii or 64% for B. garinii) but more likely to have concomitant systemic symptoms (69% vs. 38% or 37%), multiple erythema migrans skin lesions (13% vs. 5% for both B. afzelii and B. garinii), and regional lymphadenopathy (29% vs. 8% or 3%)[8–10] (Table 2). Erythema migrans lesions in patients acquiring the infection in the United States have a shorter incubation period from tick bite to lesion development and are less likely to have central clearing at the time of diagnosis.[8–10] The frequency of central clearing at least partially depends on the duration of the erythema migrans lesion before the diagnosis, and the duration is on average longer in Europe than in the United States.[8–10] In Europe, the percentage of patients with multiple erythema migrans lesions is lower for adult patients than for children,[8–11] whereas in the United States, multiple erythema migrans lesions occur with similar frequency in adults and children.[8,12–14] Patients infected with B. mayonii, found in the Upper Midwest region of the United States, can exhibit multiple and very small erythema migrans lesions.[6]

Figure 1.

Erythema migrans skin lesions from patients in Europe (A, B) and the United States (C, D).

In the United States, an entity referred to as southern tick-associated rash illness (STARI) is associated with a skin lesion very similar to erythema migrans (Figure 2). STARI, however, occurs after the bite of ticks of a different species, Amblyomma americanum, and is not caused by Lyme borrelia. The etiology of STARI has not been determined. A. americanum ticks are most frequently found in the southeastern and south-central United States, but their range is spreading to geographic areas where I. scapularis tick bites are common.[15] The potential for diagnostic confusion clearly exists in areas such as Long Island, New York, where both tick species coexist. STARI does not occur in Europe, presumably because A. americanum ticks are not found in that geographic area. Available, but limited, data suggest that STARI can be distinguished from erythema migrans on the basis of different serum metabolic profiles.[16]

Figure 2.

Southern tick-associated rash illness skin lesions. Adapted from Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, Division of Vector-Borne Diseases.

Two clinical manifestations of Lyme disease involving the skin occur exclusively in infections acquired in Europe: borrelial lymphocytoma and acrodermatitis chronica atrophicans (ACA) (Figure 3). Borrelial lymphocytoma appears as a small area of skin induration that slowly enlarges to a solitary bluish-red nodule or plaque with a diameter of up to a few centimeters and is predominantly located on the ear lobe in children and on the breast in adults. It usually develops at the site of a tick bite and is often accompanied with an erythema migrans lesion.[17] ACA is a late cutaneous manifestation of Lyme disease located primarily on the extensor parts of the distal extremities. It starts with reddish-blue discoloration and swelling of the skin (an inflammatory phase), which slowly enlarges and, if untreated, is followed by atrophic changes several months to years later. For some patients, ACA was known to have been preceded by an earlier manifestation of Lyme disease, such as erythema migrans.[18] The apparent explanation for the absence of these manifestations in the United States is that these skin infections are principally caused by B. afzelii (Table 3).

Figure 3.

A) Borrelial lymphocytoma on nipple, showing local swelling and a remnant of erythema migrans on chest; at the time of diagnosis, the lesions had been noticed for 6 weeks. B) Acrodermatitis chronica atrophicans involving the right hand, showing redpurple discoloration, swelling, and skin atrophy; at the time of diagnosis, the lesions had been noticed for ≈2.5 years.