Volume 3, Number 2—June 1997
Reply to P.D. Ellner
Reply to P.D. Ellner: We agree that diphtheria antitoxin should be administered promptly on the basis of a presumptive clinical diagnosis of respiratory diphtheria. Because laboratory confirmation may be delayed, the decision to treat with antitoxin and the dose of antitoxin must be based on the site and size of the diphtheritic membrane, the degree of toxicity, and the duration of illness (1,2). The presence of a thick grayish white adherent pseudomembrane, adenopathy and cervical swelling, and low grade fever should certainly provoke a high index of suspicion of diptheria, especially in a child who has not received pediatric immunization. The diagnosis of diptheria is primarily made presumptively on clinical grounds and confirmed by the recovery of toxigenic Corynebacterium diphtheriae by the laboratory.
Respiratory diphtheria is rare in the United States. From 1980 to 1995, only 41 cases were reported (zero to five cases in any given year) (3). With this low incidence, the likelihood that a patient with membranous pharyngitis has respiratory diphtheria is low. In addition, membranous pharyngitis could be associated with infections by other organisms such as streptococci, Epstein Barr virus, Candida albicans, Borrelia vincenti, Herpes simplex virus, Arcanobacterium hemoliticum, nontoxigenic Corynebacterium diphtheriae, and Corynebacterium pseudodiphtheriticum as in the case we reported (4-10).
The diagnosis and clinical management of exudative pharyngitis with a pseudomembrane in a country where diphtheria is extremely rare represent a dilemma for the practitioner. In weighing the benefits and risks of diphtheria antitoxin treatment, it is prudent to err on the side of using antitoxin.
- Farizo KM, Strebel PM, Chen RT, Kimbler A, Cleary TJ, Cochi SL. Fatal respiratory diphtheria due to Corynebacterium diphtheriae: case report and review of guidelines for management, investigation and control. Clin Infect Dis. 1993;16:59–68.
- American Academy of Pediatrics. Diphtheria. In: Peter G, editor. 1994 Red Book: Report of the Committee on Infectious Diseases. 23 ed. Elk Grove Village (IL): American Academy of Pediatrics, 1994:177-81.
- Bisgard KM, Hardy IRB, Popovic T, Strebel PM, Wharton M, Hadler SC. Virtual elimination of respiratory diphtheria in the United States. Abstracts of the 36th Interscience Conference on Antimicrobials and Chemotherapy; 1996 Sep 15-18; New Orleans, LA; Abstract No. K166:280.
- Wehrle PF. Diphtheria. In: Evans AS, Feldman HA, editors. Bacterial infections of humans. Epidemiology and control. New York: Plenum Medical Book Company, 1982:215.
- Diphtheria. In: Krugman S, Katz SL, Gershon AA, Wilfert CM, editors. Infectious diseases of children. St. Louis (MO): Mosby Year Book, 1992:50.
- MacGregor RR. Corynebacterium diphtheriae. In: Mandell GL, Bennett JE, Dolin R, editors. Principles and practice of infectious diseases, 4th ed. New York: Churchill Livingstone, 1995:870.
- Kain KC, Noble MA, Barteluck RL, Tubbesing RH. Arcanobacterium hemoliticum infection: confused with scarlet fever and diphtheria. J Emerg Med. 1991;9:33–5.
- Robson JMB, Harrison M, Wing LW, Taylor R. Diphtheria: may be not! Commun Dis Intell. 1996;20:64–6.
- Barksdale L, Garmise L, Horibata K. Virulence, toxinogeny, and lysogeny in Corynebacterium diphtheriae. Ann N Y Acad Sci. 1960;88:1093–108.
- Izurieta HS, Youngblood T, Strebel PM, Hollis DG, Popovic T. Exudative pharyngitis possibly due to Corynebacterium pseudodiphtheriticum, a new challenge in the differential diagnosis of diphtheria: report of a case and review. Emerg Infect Dis. 1997;3:65–8.