Persistent Atypical Lymphocytic Hyperplasia Following Tick Bite in a Child: Report of a Case and Review of the Literature

We report a 6‐year‐old girl who developed a red papule on the posterior neck at the site of a previous tick bite. Initial biopsy was performed a year after the bite and the specimen showed a dense lymphoid infiltrate with admixed CD30 + cells. The patient was referred to our center because of concern about the development of a CD30 + lymphoproliferative disorder. The lesion was completely excised. Histology showed no evidence of a clonal lymphoproliferative disorder or Borrelia infection, but persistence of CD30 + cells. This case demonstrates that a tick bite reaction can persist for more than 1 year and show immunophenotypic and morphologic overlap with a CD30 + lymphoproliferative disorder. Complete history with thorough clinical and histopathologic evaluation is necessary to arrive at the correct diagnosis.