Final answer:
The first-line treatment for most tick-borne illnesses is antibiotics, such as doxycycline or erythromycin for relapsing fevers and amoxicillin or doxycycline for Lyme disease.
Step-by-step explanation:
The first-line treatment for most tick-borne illnesses is antibiotics. These illnesses are typically caused by bacterial pathogens, which are susceptible to antibiotic treatment. For instance, the treatment for louseborne relapsing fever involves the use of antibiotics such as doxycycline or erythromycin. Similarly, tickborne relapsing fever is treated using tetracycline or erythromycin. Lyme disease, another common tick-borne illness, is treated with antibiotics like amoxicillin, doxycycline, or in the later stages with intravenous drugs such as penicillin G, chloramphenicol, or ceftriaxone.