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Medical Author:

Steven Doerr, MD

Steven Doerr, MD

Steven Doerr, MD, is a U.S. board-certified Emergency Medicine Physician. Dr. Doerr received his undergraduate degree in Spanish from the University of Colorado at Boulder. He graduated with his Medical Degree from the University Of Colorado Health Sciences Center in Denver, Colorado in 1998 and completed his residency training in Emergency Medicine from Denver Health Medical Center in Denver, Colorado in 2002, where he also served as Chief Resident.

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Medical Editor:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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In this Article

• What is diphtheria?
• What is the history of diphtheria?
• What causes diphtheria?
• How is diphtheria transmitted?
• What are the signs and symptoms of diphtheria?
• How is diphtheria diagnosed?
• What is the treatment for diphtheria?
• What are the complications of diphtheria?
• How is diphtheria prevented?
• Diphtheria At A Glance
• Diphtheria Index

The diagnosis of diphtheria is confirmed by isolation of the bacterium Corynebacterium diphtheriae. Diagnostic tests to isolate the bacterium involve obtaining cultures from the nose and throat in any individual suspected of having diphtheria, as well as their close contacts.

It is also important to determine whether or not the isolate is capable of producing diphtheria toxin, and this can be accomplished by testing in specialized laboratories. Finally, determining the patient's antibody levels to diphtheria toxin can also be helpful for evaluating the probability of the diagnosis of diphtheria and the potential for severe illness.

Other tests, such as ECG, imaging studies, and blood work can also help assess the extent of involvement of the disease.

If diphtheria is suspected in a patient, prompt treatment should be undertaken even before confirmatory lab results are available.

Diphtheria antitoxin is the mainstay of therapy. It neutralizes circulating diphtheria toxin and reduces the progression of the disease. The effectiveness of diphtheria antitoxin is greatest if it is administered early in the course of the disease. The U.S. Centers for Disease Control and Prevention (CDC) can assist in obtaining the diphtheria antitoxin. Antitoxin is not recommended for asymptomatic carriers and it is usually of no value in localized cutaneous diphtheria.

Antibiotics should also be administered as soon as possible to patients with suspected diphtheria. Antibiotics help eradicate the bacteria, thereby stopping toxin production, and they also help to prevent transmission of diphtheria to close contacts. Penicillin and erythromycin are the recommended antibiotics. Asymptomatic carriers, as well as all close contacts potentially exposed to diphtheria, also require antibiotic treatment.

Supportive measures, such as inserting a breathing tube (intubation), may be necessary if the patient cannot breathe on their own or if there is the potential for airway obstruction. Potential cardiac and neurologic complications also need to be closely followed and addressed in consultation with the proper specialist.