Non immunized susceptible diphtheria contacts should receive:
Non immunized contacts should receive prophylactic penicillin or erythromycin. They should also be given 1000 to 2000 units of antitoxin and actively immunized against diphtheria. Ref: Park 21st edition, page 151.
Erythromycin
Penicillin and diphtheria antitoxin
Penicillin, diphtheria antitoxin and DPT vaccine
No treatment is required