Late Lyme Borreliosis Presenting with Chronic Painful Sensory Axonal Polyneuropathy Preceding Clinically Apparent Acrodermatitis Chronica Atrophicans: A Case Report

Background: Lyme borreliosis is a multisystem tick-borne infection with heterogeneous clinical manifestations involving the skin, nervous system, joints, and other organs. Acrodermatitis chronica atrophicans (ACA) is the characteristic late cutaneous manifestation of European Lyme borreliosis and may be associated with peripheral neurological involvement. An atypical temporal sequence of neurological and cutaneous manifestations may delay diagnosis. Case Presentation: We report the case of a 78-year-old woman with more than one year of painful sensory symptoms affecting both feet and distal lower legs. Electroneurography demonstrated a sensory axonal polyneuropathy, and diagnostic investigations did not identify common metabolic, nutritional, autoimmune, infectious, and paraproteinaemic causes. Approximately 15 months later, she developed a progressive painful erythematous and oedematous lesion of the right lower leg. Histopathological findings were nonspecific and initially favoured interstitial granuloma annulare; however, PCR detected Borrelia DNA in the skin biopsy. Together with positive Borrelia serology and the clinical findings, this confirmed cutaneous Lyme borreliosis, with ACA considered the clinically favoured manifestation, although erythema migrans could not be definitively excluded. Cerebrospinal fluid analysis demonstrated lymphocytic pleocytosis and blood–CSF barrier dysfunction without intrathecal Borrelia-specific antibody synthesis. The overall findings supported a possible association between the sensory axonal polyneuropathy and Lyme borreliosis, although a coincidental unrelated polyneuropathy could not be excluded. Treatment with doxycycline resulted in near-complete resolution of the skin lesions and partial improvement of neuropathic pain. Conclusions: This case highlights the diagnostic challenges of late Lyme borreliosis presenting with chronic painful sensory axonal polyneuropathy preceding a cutaneous manifestation clinically considered most consistent with ACA by approximately 15 months. Although a direct causal relationship between the neuropathy and Borrelia infection cannot be definitively established, the overall clinicopathological findings support a possible association between the sensory axonal polyneuropathy and late Lyme borreliosis. Clinicians should consider late Lyme borreliosis in patients with otherwise unexplained painful sensory neuropathy when compatible cutaneous manifestations or other clinical features increase the pretest probability of Borrelia infection.