Lichen sclerosus et atrophicans (LSA) is a chronic, inflammatory skin disease of unknown etiology, characterized by atrophy. We report a case of LSA with frontoparietal distribution, mimicking scleroderma en coup de sabre, causing scarring alopecia. The case was associated with Borrelia infection. The lesion improved with 2 cycles of antibiotic therapy with ceftriaxone 2 gr /day i.v for 21 days associated with UVA-1 therapy and local and systemic vitamin E supply (400 mg 2x/day per os for 3 months). This case stresses the importance of identifying clinical manifestations associated with Lyme disease and the use of tissue PCR to detect borrelial DNA in patients with these lesions, but characterized by negative serology for Borrelia