Annular Erythema Induced by Tick Bites due to 183 Larvae of Amblyomma testudinarium

Abstract

A 77-year-old Japanese woman went to neighboring mountain to pick up wild plants and noticed multiple reddish papules with itching on the left forearm in the evening of the day. Gradually, the area of eruption expanded on the trunk and extremities. Upon examination, 183 erythematous lesions were found, and 31 of them were with ticks. All ticks were removed by forceps easily, and they were identified as larval Amblyomma testudinarium. She was treated with 100 mg/day of minocycline, 5 mg/day of levocetirizine, and topical diflucortolone valerate. Eruption were improved, however, annular erythema which resembled erythema mirgans of Lyme disease appeared after seven days from onset. Serum samples obtained at 7th day were examined at National Institute of Infectious Diseases, but antibodies against Borrelia garinii, or Borrelia afzelii were negative. Lyme disease-like nnular erythema observed after tick (A. testudinarium and I. persulcatus) bites without clear evidence of borrelial infection has been reported as tick-associated rash illness or TARI. Our case is compatible with this condition. Interestingly, some ticks were found in the seborrheic keratosis located on the lower legs, and the lesion rapidly protruded. In case of multiple tick bites, one have to be careful with the presence of ticks in such keratotic lesions.