My Husband Has Had Severe Muscle Aches And Pains For

My husband has had severe muscle aches and pains for about a week now, he also has a rash over his back, stomach, arms, face but not his lower body. Has had the chills and sweats too. At the doctor they gave him A prescription to treat a tick borne illness. There is no bite mark area and the rash is not bullseye shaped. Does this sound like correct diagnosis?