Southern Tick-Associated Rash Illness
A 65-year-old man presented to the dermatology clinic with a 1-day history of an itchy rash on his left hip. One week earlier, he had removed a tick — an adult, female lone star tick (Amblyomma americanum) — from his hip after doing yard work near the woods by his home in Tennessee (Panel A). On physical examination, an erythematous plaque 15 cm in diameter was seen on the hip; central clearing and a crusted papule in the center created a bull’s-eye appearance (Panel B). A clinical diagnosis of southern tick-associated rash illness (STARI) was made. STARI is characterized by an erythema migrans–like rash with or without mild constitutional symptoms. The causative organism is unknown, so no diagnostic test exists. The lone star tick, which had formerly been found only in the southern United States (including Tennessee, as in this case), is now also found in the northeastern United States. This change in distribution is attributable at least in part to climate change, and further geographic spread of the vector and a longer active season are anticipated as temperatures increase. Treatment of STARI is supportive, but antimicrobial therapy is recommended for an erythema migrans–like rash in regions where STARI and Lyme disease coexist. After a 2-week course of topical glucocorticoids, the rash resolved. source:nejm.org
