A Skin Lesion in a Patient from Kentucky

Abstract

Diagnosis: Southern tick-associated rash illness (STARI). STARI manifests as a skin lesion (figure 1) and is considered indistinguishable from erythema migrans, a characteristic skin manifestation of Borrelia burgdorferi infection (Lyme disease) [1-4]. As was the case with our patient, some patients with STARI recall that the rash was preceded by the bite of an Amblyomma americanum tick, also known as the lone star tick because of the appearance of a distinctive white spot on the dorsal surface of the adult female of this species (figure 2). The adult male and the nymph (figure 3) of this tick do not manifest this spot. Borrelia lonestari, a species phylogenetically distinct from B. burgdorferi, is considered to be a possible etiologic agent for this illness, on the basis of its identification by PCR in ~2% of A. americanum ticks from many locations in the southeastern and south-central United States [5-7]. In a single case, DNA of B. lonestari was amplified from both the erythema migranslike skin lesion and the associated A. americanum tick [6]. However, Wormser et al. [8; in this issue] studied skin biopsy specimens from 30 patients from Missouri with erythema Figure 2. An adult female Amblyomma americanum tick