A-Z Index × Submit A-Z Index × Submit A-Z Index Search Dropdown × Submit Facebook Twitter LinkedIn Syndicate Emerging Infectious Disease journal ISSN: 1080-6059 Disclaimer: Early release articles are not considered as final versions. Any changes will be reflected in the online version in the month the article is officially released.
Southern tick–associated rash illness (STARI) is a tickborne disease of unknown etiology characterized by an erythema migrans–like skin lesion. We report a STARI case in New York in a child after an Amblyomma americanum tick bite; we detected Borrelia lonestari , a disputed cause of STARI, in the tick.
Southern tick–associated rash illness (STARI) is a tickborne disease of unknown etiology. Its hallmark finding is an erythema migrans (EM)–like skin lesion after a lone star tick ( Amblyomma americanum ) bite. Although it is considered self-limited, STARI is difficult to diagnose and manage because of characteristics similar to Lyme disease. STARI is not known to cause any sequelae after rash resolution; the role of antimicrobial drugs in proven cases is therefore undetermined ( 1 ).
Previous descriptions of STARI focused on the southern United States. Because lone star tick populations have increased in the mid-Atlantic and northeastern United States, regions highly endemic to Lyme disease, differentiating STARI from Lyme disease has become a challenge ( 2 ). We describe the case of a child evaluated in Long Island, New York, USA for an EM-like skin lesion.
Figure 1 . Erythema migrans–like skin lesion at the site of a tick bite on patient’s upper back in study of southern tick–associated rash illness in pediatric patient, New York, USA, 2025.
An 8-year-old girl with a history of asthma and allergic rhinitis living in eastern Long Island was brought in June 2025 for evaluation of a recent EM-like lesion. Approximately 2 weeks before her visit, she had a 5-cm annular lesion with peripheral erythema and a central nodule on the upper back ( Figure 1 ). She also experienced low-grade fever, posterior cervical lymphadenopathy, and myalgia. A tick had been removed from the lesion site and stored in a sealed bag 12 days before the rash began. The patient did not receive doxycycline postexposure prophylaxis. Because early localized Lyme disease was suspected, her pediatrician prescribed a 2-week course of amoxicillin. The rash and associated symptoms resolved within 1 week. She was asymptomatic at the time of the follow-up consultation.
Figure 2 . Adult male lone star tick ( Amblyomma americanum ) from study of southern tick–associated rash illness in pediatric patient, New York, USA, 2025. The tick was removed from the patient...
Although care providers initially suspected Lyme disease, the biting tick was identified as an adult male lone star tick ( Figure 2 ), which does not transmit Borrelia burgdorferi , which mean the patient’s signs and symptoms were consistent with a diagnosis of STARI. We extracted DNA from the tick, performed nested PCR targeting the Borrelia flagellin gene ( 3 ), and confirmed the presence of a B. lonestari –specific sequence (GenBank accession no. PZ457021).
A. americanum , an aggressive tick species, has expanded across the United States ( 2 , 3 ). In the US Northeast, diagnosing STARI is challenging because of a high rate of B. burgdorferi –infected Ixodes scapularis ticks ( 2 ). As A. americanum tick populations have increased across Long Island, the proportion of EM lesions cau…