NEW YORK, June 20 (Praxis Press) Lyme disease typically presents with a skin lesion called erythema migrans (EM), which may be confused with cellulitis. The first-generation cephalosporin, cephalexin monohydrate, is effective for treating bacterial cellulitis but has not been recommended or studied for treating Lyme disease. In order to describe the outcome of patients with EM when treated with cephalexin, Nowakowski and colleagues evaluated 393 patients with Lyme disease, 11 of whom were treated with cephalexin. All 11 of these patients showed signs of Lyme disease progression. Cephalexin should not be used to treat early Lyme disease and should be prescribed with caution during the summer months for patients believed to have cellulitis in locations where Lyme disease is endemic.