eMedicine Specialties > Infectious Diseases > Bacterial Infections

Botulism: Differential Diagnoses & Workup

Author: Kirk M Chan-Tack, MD, Fellow, Division of Infectious Disease, University of Maryland School of Medicine
Coauthor(s): John Bartlett, MD, Chief of Division of Infectious Diseases, Chief of HIV Care Service, Professor, Department of Internal Medicine, Johns Hopkins University School of Medicine
Contributor Information and Disclosures

Updated: Sep 23, 2008

Differential Diagnoses

Hypermagnesemia
Hyperthyroidism
Mediterranean Fever, Familial

Other Problems to Be Considered

The diseases most frequently confused with botulism are those that produce generalized weakness. Differentiating botulism from other diseases is essential for early initiation of therapy. Botulism should be considered in patients who are afebrile and mentally intact and who have symmetric descending paralysis without sensory findings. The diagnosis should be suspected on clinical grounds in the context of an appropriate history. Other conditions often confused with botulism include the following:

  • Guillain-Barré syndrome
  • Fisher variant of Guillain-Barré syndrome
  • Myasthenia gravis
  • Lambert-Eaton syndrome
  • Poliomyelitis
  • Tick paralysis
  • Cerebrovascular disease of the brainstem
  • Basilar artery stroke
  • Encephalitis
  • Diphtheria
  • Neurasthenia
  • Progressive external ophthalmoplegia
  • Intracranial mass lesions
  • Drugs, penicillamine
  • Aminoglycosides: Very large doses can induce neuromuscular blockade.
  • Poisonings by atropine, scopolamine, organophosphate insecticides, shellfish, amanita mushrooms, carbon monoxide, methyl alcohol, methyl chloride, and sodium fluoride
  • Congenital neuropathy or myopathy

Workup

Laboratory Studies

  • Laboratory tests are not helpful in the routine diagnosis of botulism.
  • WBC counts and erythrocyte sedimentation rates are normal.
  • Cerebrospinal fluid is normal, except for occasional mild elevations in protein concentration.
  • A mouse neutralization bioassay confirms botulism by isolating the botulism toxin.
  • Toxin may be identified in serum, stool, vomitus, gastric aspirate, and suspected foods. C botulinum may be grown on selective media from samples of stool or foods. Note that the specimens for toxin analysis should be refrigerated, but culture samples of C botulinum should not be refrigerated.
  • Because intestinal carriage is rare, identifying the organism or its toxin in vomitus, gastric fluid, or stool strongly suggests the diagnosis.
    • Isolation of the organism from food without toxin is insufficient grounds for the diagnosis.
    • Only experienced personnel who have been immunized with botulinum toxoid should handle the specimens.
    • Because the toxin may enter the blood stream through the eye or via small breaks in the skin, precaution is warranted.
  • Wound cultures that grow C botulinum suggest of wound botulism.

Imaging Studies

  • Imaging studies are generally not useful in the diagnosis of botulism.
  • The only potential role for imaging studies (eg, CT scan, MRI) would be to rule out CNS pathology, such as intracranial mass lesions, cerebrovascular disease of the brainstem, or basilar artery stroke, in patients in whom the presentation is atypical or vague.

Other Tests

  • Patients with botulism may have mild nonspecific abnormalities on electrocardiography.
  • Results from nerve conduction studies are normal, and electromyography (EMG) reveals reduced amplitude of compound muscle action potentials.
  • EMG may be useful in establishing a diagnosis of botulism, but the findings can be nonspecific and nondiagnostic, even in severe cases.
    • Characteristic findings in patients with botulism include brief low-voltage compound motor-units, small M-wave amplitudes, and overly abundant action potentials. An incremental increase in M-wave amplitude with rapid repetitive nerve stimulation may help to localize the disorder to the neuromuscular junction.
    • Single-fiber EMG may be a more useful and sensitive method for the rapid diagnosis of botulism intoxication, particularly in the absence of signs of general muscular weakness.
  • The results of the edrophonium chloride, or Tensilon, test for myasthenia gravis may be falsely positive in patients with botulism. If positive, it is typically much less dramatically positive than in patients with myasthenia gravis.

More on Botulism

Overview: Botulism
Differential Diagnoses & Workup: Botulism
Treatment & Medication: Botulism
Follow-up: Botulism
Multimedia: Botulism
References
[ CLOSE WINDOW ]

References

  1. [Guideline] Bossi P, Tegnell A, Baka A, et al. Bichat guidelines for the clinical management of botulism and bioterrorism-related botulism. Euro Surveill. Dec 15 2004;9(12):E13-4. [Medline].

  2. Passaro DJ, Werner SB, McGee J, et al. Wound botulism associated with black tar heroin among injecting drug users. JAMA. Mar 18 1998;279(11):859-63. [Medline].

  3. Shaffer N, Wainwright RB, Middaugh JP, et al. Botulism among Alaska Natives. The role of changing food preparation and consumption practices. West J Med. Oct 1990;153(4):390-3. [Medline].

  4. Angulo FJ, Getz J, Taylor JP, et al. A large outbreak of botulism: the hazardous baked potato. J Infect Dis. Jul 1998;178(1):172-7. [Medline].

  5. St Louis ME, Peck SH, Bowering D, et al. Botulism from chopped garlic: delayed recognition of a major outbreak. Ann Intern Med. Mar 1988;108(3):363-8. [Medline].

  6. Arnon SS. Creation and development of the public service orphan drug Human Botulism Immune Globulin. Pediatrics. Apr 2007;119(4):785-9. [Medline].

  7. Cai S, Singh BR, Sharma S. Botulism diagnostics: from clinical symptoms to in vitro assays. Crit Rev Microbiol. Apr-Jun 2007;33(2):109-25. [Medline].

  8. Cardoso F, Jankovic J. Clinical use of botulinum neurotoxins. Curr Top Microbiol Immunol. 1995;195:123-41. [Medline].

  9. Cherington M. Botulism: update and review. Semin Neurol. Jun 2004;24(2):155-63. [Medline].

  10. Clemmens MR, Bell L. Infant botulism presenting with poor feeding and lethargy: a review of 4 cases. Pediatr Emerg Care. Jul 2007;23(7):492-4. [Medline].

  11. Critchley EM, Mitchell JD. Human botulism. Br J Hosp Med. Apr 1990;43(4):290-2. [Medline].

  12. Fox CK, Keet CA, Strober JB. Recent advances in infant botulism. Pediatr Neurol. Mar 2005;32(3):149-54. [Medline].

  13. Glik D, Harrison K, Davoudi M, et al. Public perceptions and risk communications for botulism. Biosecur Bioterror. 2004;2(3):216-23. [Medline].

  14. Hallett M. One man's poison--clinical applications of botulinum toxin. N Engl J Med. Jul 8 1999;341(2):118-20. [Medline].

  15. Hatheway CL. Botulism: the present status of the disease. Curr Top Microbiol Immunol. 1995;195:55-75. [Medline].

  16. Jahn R, Niemann H. Molecular mechanisms of clostridial neurotoxins. Ann N Y Acad Sci. Sep 15 1994;733:245-55. [Medline].

  17. Lawrence DT, Dobmeier SG, Bechtel LK, et al. Food poisoning. Emerg Med Clin North Am. May 2007;25(2):357-73; abstract ix. [Medline].

  18. Lecour H, Ramos H, Almeida B, et al. Food-borne botulism. A review of 13 outbreaks. Arch Intern Med. Mar 1988;148(3):578-80. [Medline].

  19. Long SS. Infant botulism and treatment with BIG-IV (BabyBIG). Pediatr Infect Dis J. Mar 2007;26(3):261-2. [Medline].

  20. Oguma K, Fujinaga Y, Inoue K. Structure and function of Clostridium botulinum toxins. Microbiol Immunol. 1995;39(3):161-8. [Medline].

  21. Roblot P, Roblot F, Fauchere JL, et al. Retrospective study of 108 cases of botulism in Poitiers, France. J Med Microbiol. Jun 1994;40(6):379-84. [Medline].

  22. Schiavo G, Rossetto O, Tonello F, et al. Intracellular targets and metalloprotease activity of tetanus and botulism neurotoxins. Curr Top Microbiol Immunol. 1995;195:257-74. [Medline].

  23. Shapiro RL, Hatheway C, Swerdlow DL. Botulism in the United States: a clinical and epidemiologic review. Ann Intern Med. Aug 1 1998;129(3):221-8. [Medline].

  24. Slater PE, Addiss DG, Cohen A, et al. Foodborne botulism: an international outbreak. Int J Epidemiol. Sep 1989;18(3):693-6. [Medline].

  25. Sobel J, Tucker N, Sulka A, et al. Foodborne botulism in the United States, 1990-2000. Emerg Infect Dis. Sep 2004;10(9):1606-11. [Medline].

  26. Varma JK, Katsitadze G, Moiscrafishvili M, et al. Signs and symptoms predictive of death in patients with foodborne botulism--Republic of Georgia, 1980-2002. Clin Infect Dis. Aug 1 2004;39(3):357-62. [Medline].

  27. Weber JT, Goodpasture HC, Alexander H, et al. Wound botulism in a patient with a tooth abscess: case report and review. Clin Infect Dis. May 1993;16(5):635-9. [Medline].

  28. Wilcox PG, Morrison NJ, Pardy RL. Recovery of the ventilatory and upper airway muscles and exercise performance after type A botulism. Chest. Sep 1990;98(3):620-6. [Medline].

[ CLOSE WINDOW ]

Further Reading

[ CLOSE WINDOW ]

Keywords

botulism, human botulism, Clostridium botulinum, C botulinum, foodborne botulism, food-borne botulism, wound botulism, infant botulism, infantile botulism, CB toxin, botulinum toxin, FBB, WB, food poisoning

[ CLOSE WINDOW ]

Contributor Information and Disclosures

Author

Kirk M Chan-Tack, MD, Fellow, Division of Infectious Disease, University of Maryland School of Medicine
Kirk M Chan-Tack, MD is a member of the following medical societies: American College of Physicians, American Medical Association, Christian Medical & Dental Society, Physicians for Social Responsibility, and Southern Medical Association
Disclosure: Nothing to disclose.

Coauthor(s)

John Bartlett, MD, Chief of Division of Infectious Diseases, Chief of HIV Care Service, Professor, Department of Internal Medicine, Johns Hopkins University School of Medicine
John Bartlett, MD is a member of the following medical societies: Alpha Omega Alpha, American College of Clinical Pharmacology, American College of Physicians, American Society for Microbiology, American Society of Tropical Medicine and Hygiene, American Thoracic Society, American Venereal Disease Association, Association of American Physicians, Infectious Diseases Society of America, and Society of Critical Care Medicine
Disclosure: Nothing to disclose.

Medical Editor

David Hall Shepp, MD, Program Director, Fellowship in Infectious Diseases, Department of Medicine, North Shore University Hospital; Associate Professor, New York University School of Medicine
David Hall Shepp, MD is a member of the following medical societies: Infectious Diseases Society of America
Disclosure: Gilead Sciences Salary Management position

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment

Managing Editor

Ronald A Greenfield, MD, Professor, Department of Internal Medicine, Section of Infectious Diseases, University of Oklahoma College of Medicine
Ronald A Greenfield, MD is a member of the following medical societies: American College of Physicians, American Federation for Medical Research, American Society for Microbiology, Central Society for Clinical Research, Infectious Diseases Society of America, Medical Mycology Society of the Americas, Phi Beta Kappa, Southern Society for Clinical Investigation, and Southwestern Association of Clinical Microbiology
Disclosure: Pfizer Honoraria Speaking and teaching; Gilead Honoraria Speaking and teaching; Ortho McNeil Honoraria Speaking and teaching; Wyeth Honoraria Speaking and teaching; Abbott Honoraria Speaking and teaching; Astellas Honoraria Speaking and teaching; Cubist  Speaking and teaching

CME Editor

Eleftherios Mylonakis, MD, Clinical and Research Fellow, Department of Internal Medicine, Division of Infectious Diseases, Massachusetts General Hospital
Eleftherios Mylonakis, MD is a member of the following medical societies: American Association for the Advancement of Science, American College of Physicians, American Society for Microbiology, and Infectious Diseases Society of America
Disclosure: Nothing to disclose.

Chief Editor

Burke A Cunha, MD, Professor of Medicine, State University of New York School of Medicine at Stony Brook; Chief, Infectious Disease Division, Winthrop-University Hospital
Burke A Cunha, MD is a member of the following medical societies: American College of Chest Physicians, American College of Physicians, and Infectious Diseases Society of America
Disclosure: Nothing to disclose.

 
 
HONcode

We subscribe to the
HONcode principles of the
Health On the Net Foundation

All material on this website is protected by copyright, Copyright© 1994- by Medscape.
This website also contains material copyrighted by 3rd parties.

DISCLAIMER: The content of this Website is not influenced by sponsors. The site is designed primarily for use by qualified physicians and other medical professionals. The information contained herein should NOT be used as a substitute for the advice of an appropriately qualified and licensed physician or other health care provider. The information provided here is for educational and informational purposes only. In no way should it be considered as offering medical advice. Please check with a physician if you suspect you are ill.