Table3. Infectious Disease Society of America guidelines for the treatment of Lyme disease (17)*.

Treatment of adults and children older than 8 years with Lyme disease	Erythema migrans or early disseminated disease, including Bell’s palsy, but without other CNS involvement	Doxycycline 100 mg po bid x 14–21 days (contraindicated in pregnancy) Amoxicillin 500 mg po tid x 14–21 days Cefuroxime 500 mg po bid x 14–21 days
	Early Lyme with CNS involvement	Ceftriaxone 2 g IV once daily x 14–28 days Pen G 4 x106 units IV q 4 h x 14–28 days Doxycycline 100–200 mg po bid x 28 days (alternative if others not possible)
	Early Lyme with carditis	Same treatment as early Lyme with CNS involvement, but use IV initially with high grade heart block or if admission to hospital is necessary.
	Late Lyme without CNS involvement**	Doxycycline 100 mg po bid x 8 days Amoxicillin 500 mg po id x 28 days Cefuroxime 500 mg po bid x 28 days
	Late Lyme with CNS involvement (late neuroborreliosis)	Ceftriaxone 2 g IV once daily x 14–28 days Pen G 4 x106 units IV q 4 h x 14–28 days
Treatment of children 8 years or younger with Lyme disease	Early localized disease	Amoxicillin 30 mg/kg per day, orally, divided into three doses (max 1.5 g/day) for 14–21 days For children allergic to penicillin, cefuroxime 30 mg/kg per day, orally, in two divided doses (maximum 1 g/day) for 14–21 days
	Early disseminated and late disease: multiple erythema migrans	Oral treatment as the above for 21 days
	Early disseminated and late disease: isolated facial palsy and first episodes of arthritis	Oral treatment as the above for 21 days
	Early disseminated and late disease: persistent/recurrent arthritis, carditis and meningitis/encephalitis	Ceftriaxone or penicillin IV at pediatric dosing

^* These recommendations are off-label, evidence-based best practices.
^** Recurrent or persistent joint swelling – repeat 4 week course of oral antibiotic as above. Use of IV ceftriaxone should be reserved for relapse or persistent joint swelling without improvement with oral treatment.
CNS = central nervous system.