Final answer:
Diphtheria requires treatment with antibiotics to control the bacterial infection and antitoxin to neutralize the diphtheria toxin produced by Corynebacterium diphtheriae. Antibiotics alone are not effective against the toxin, hence the need for antitoxin, which may cause serum sickness due to their horse-derived proteins.
Step-by-step explanation:
When diphtheria is diagnosed, it is critical to administer both antibiotics and antitoxin. The causative agent, Corynebacterium diphtheriae, produces a potent diphtheria toxin that causes tissue death and inflammation, leading to the formation of the characteristic pseudomembrane. Antibiotics such as penicillin and erythromycin are used to control the bacterial infection, but they have no effect on preformed toxins. Therefore, antitoxins, which are preformed antibodies against the toxin, are necessary to neutralize the toxin and prevent further damage to the body. However, these antitoxins can cause serum sickness in some patients because they are produced in horses and the human immune system can react against the non-human proteins.