infectious diseases
Diphtheria
Key Points
Usually, diphtheria is a cutaneous or nasopharyngeal infection, but a potent toxin can damage the heart, nerves, and sometimes the kidneys. Diphtheria is rare in high-income countries because of widespread vaccination but is endemic in many low- and middle-income countries; rates are increasing slightly in high-income countries because rates of vaccination and revaccination are declining. Pharyngeal infection causes a characteristic membrane in the tonsillar area; it may initially appear as a white, glossy exudate but typically becomes dirty gray, tough, fibrinous, and adherent. Treat with diphtheria antitoxin and penicillin orerythromycin; document cure by culture. Vaccinate patients after recovery, and vaccinate close contacts who have not completed a primary series or who have gone>5 years since their last booster. Do nasopharyngeal and throat cultures of close contacts regardless of their immunization status. Give antibiotics to close contacts; duration of treatment depends on culture results. 