It depends on the organism.
S. pyogenes: part of life, human to human spread. It can be spread by food leading to outbreaks (PubMed).
Viral: Adenovirus (Pharyngoconjunctival fever), Coronavirus, Coxsackievirus A (Herpangina and hand-foot-and-mouth disease), Cytomegalovirus, Epstein-Barr virus, Herpes simplex virus types 1 and 2, HIV (Primary HIV infection), Influenza A and B viruses, Parainfluenza virus, Rhinovirus.
Bacteria: S. pyogenes, Group C and G streptococci, Arcanobacterium haemolyticum, Corynebacterium diphtheriae, Francisella tularensis, Mycoplasma pneumoniae, Mixed anaerobes Vincent's angina, N. gonorrhoeae(PubMed), Yersinia enterocolitica, Yersinia pestis.
Penicillin VK, amoxicillin, any oral cephalosporin, and any oral macrolides will probably take care of group A streptococcal pharyngitis (IDSA Guidelines). The rest depends on what you grow or suspect from history.
One meta-analysis suggests "There is considerable evidence to suggest that clindamycin and amoxicillin with clavulanate is superior to penicillin" for treatment and preventing relapse (PubMed).
In kids one 750 mg or 1 gm dose of amoxicillin is curative (but will not prevent Rheumatic Fever which requires 10 count 'em 10 days of therapy (PubMed)). Or does it? There is a great review called Hostage to History The Duration of Antimicrobial Treatment for Acute Streptococcal Pharyngitis (PubMed) which I suggest you pull and read. The take home:
"The 10-day treatment standard evolved without scientific justification. There have been no therapeutic trials that have validated the necessity for 10 days of oral antimicrobial treatment. Yet, despite the lack of a scientific foundation, the rarity of acute rheumatic fever in developed countries, the high failure rate for streptococcal eradication and evidence that short-course therapy with a non-penicillin antimicrobial yields equivalent eradication rates, the 10-day rule persists because of long clinical usage and the inherent power of the number 10."
Chlorhexidine gluconate and benzydamine hydrochloride mouth spray, in addition to antibiotic treatment, significantly decreased the intensity pain in patients with streptococcal pharyngitis, although endpoint was the same (PubMed).
Probiotics do nothing for symptoms (PubMed).
Watch for abscesses; will often present as asymmetry of the back of the throat.
Prophylaxis of family members to prevent spread doth not work (PubMed).
Recurrent disease in adults can be treated by removing the tonsils (PubMed).
"Acute non-rheumatic streptococcal myocarditis is an under-recognized and treatable cause of ST segment elevation and chest pain in young adults with a history of recent pharyngitis (PubMed)."
Relevant links to my Medscape blog
Last Update: 02/24/19.