Sore throat, low-grade fever, dysphagia, membrane in tonsillar area ("dirty gray, tough, fibrinous, and adherent"); [Merck Manual] Gradual onset of fever, difficulty swallowing, & hoarseness if larynx involved; Membrane appears on days 2-3; [CDC Travel]
Swelling of the neck may give patients a "bull neck" appearance. The main complications of diphtheria are airway obstruction, myocarditis, and neuropathy. Myocarditis, usually first detected by EKG about 7-14 days after disease onset, can cause severe conduction abnormalities and death. Neuropathy may begin with palatal weakness and later progress to cranial nerve palsies and paralysis of the diaphragm and extremities. Other complications of severe disease include thrombocytopenia, acute renal failure, and disseminated intravascular coagulation. [Guerrant, p. 224-5] A potent toxin, produced by the growing bacteria, injures the nerves, heart, and kidneys. Neuropathy of some kind develops in about 15% of untreated patients and in about 75% of patients with severe disease. A polyneuropathy, resembling Guillain-Barre syndrome, is delayed in onset and usually appears about 2-3 months after onset of the illness. Patients with skin lesions may act as chronic carriers, but do not usually suffer from the toxic manifestations of the disease. Patients with nasal diphtheria have blood-tinged discharge and also may act as carriers [ID, p. 1339, 1625] Cutaneous diphtheria may begin as a blister or pustule that progresses to an ulcer, usually on an extremity. [Guerrant, p. 225] Toxic complications are rare in cutaneous diphtheria because the toxin in poorly absorbed through the skin. [Merck Manual, p. 1239] Patients with obstructive laryngotracheitis caused by the membrane have hoarseness, cough, and dyspnea. [5MCC-2015] Infection is fatal in about 4% to 12% of cases. Death usually occurs in the first 3-4 days, and it is caused by asphyxiation or myocarditis. Pharyngitis, fever, and dysphagia are the most common symptoms. A membrane and cervical lymphadenopathy are observed in only about 1/2 of patients. Peripheral neuritis becomes manifest as weakness or paralysis from 10 days to 3 months after the primary throat infection. Invasive disease (endocarditis, osteomyelitis, and arthritis) caused by nontoxigenic strains has been recently described. Drug addicts and alcoholics are at increased risk. [PPID, p. 2369-70] Neurological complications in the first 2 weeks include dysphagia and cranial nerve effects (weakness of tongue, facial numbness, and blurred vision). [Harrison, p. 601]
Only 18 cases were reported in the USA between 1980 and 1994. Transmission occurs by contact with infected patients through respiratory droplets or skin lesions. [Guidelines for Infection Control in Health Care Personnel. CDC. 1998] Unimmunized children under the age of 15 are most susceptible. Outbreaks in recent years occurred in Ecuador and countries of the former Soviet Union. Transmission by raw milk has been reported. [CCDM, p. 151] Patients with cardiac involvement have a poor prognosis. A 30-40% mortality rate is associated with bacteremia. [Gorbach, p. 153]
For updated text and symptoms of infectious diseases, see iddx.com.
Clinical--treat if suspected; Culture (selective media required); [ID, p. 1339] Test all C. diphtheria strains isolated for toxigenicity. [Cecil, p. 1834] A rapid method available in some labs: IFA staining of a 4-hour culture; [ABX Guide: C. diphtheriae]