Case of the Month #10

Martin Smith

You are asked to review a 25-year-old female office worker who has presented to ENT with a sore throat and a progressive dysphagia.

She is apyrexial, haemodynamically stable and fully concious. A full examination reveals extensive wounds across her thighs due to subcutaneous heroin injection.  

Her neurology continues to progress over the next 24 hours, and she develops diplopia followed by a loss of motor power in her arms. She then loses the ability to stand from sitting but has no sensory loss. She subsequently deteriorates into respiratory failure, ultimately requiring intubation and ventilation.  A clinical diagnosis of botulism is made. 

Why was botulism suspected? 

There are number of differentials in this case. They can be broadly distinguished clinically by the history and a thorough examination. In addition, the presence, or lack of; a febrile illness, cranial nerve involvement, sensory changes and an ascending vs descending muscle paralysis can help narrow the diagnosis further.

This patient demonstrated the ‘5D’s of botulism’ (Diplopia, Dysarthria, Dysphagia, Dyspnoea, Descending paralysis).

What are the causes of botulism? 

  • Clostridium botulinim is a naturally occurring Gram positive organism. 
  • The organism is isolated in only 41% of cases of Botulism
  • Human disease is caused by Serotypes A,B or E
  • The organism is found in soil, dust and aquatic sediments. 
  • 5 main vectors:  
  • Food borne  
  • Wound botulism (most common in UK) 
  • Intestinal colonisation (infants) 
  • Deliberate release (weapons) 
  • Iatrogenic 
  • Wound colonisation was first described in 2000, exclusively amongst the intravenous drug using population. 
  • Direct injection of heroin, often dissolved in citric acid, into muscle or under the skin provides optimum conditions for bacterial growth. (“Skin popping”)  

What is the treatment of bolulism?  

  • Supportive care
  • Treatment with Penicillin G is recommended for wound botulism. 
  • Antitoxin can reduce severity of symptoms if given early, but will not reverse paralysis. 
  • A Forced Vital Capacity of below 12ml/kg has been suggested as an indication for mechanical ventilation. 
  • If possible, the diagnosis should be confirmed via isolation of the toxin or by culture of C. botulinum
  • Early input from microbiology and infectious disease specialists is recommended. 

What is the prognosis? 

  • Mortality is between 7 and 10%. 
  • It can take up to a year for respiratory muscle strength to return. 
  • Non-specific weakness and shortness of breath may persist longer. 

Key take home messages

  • Acute onset neurological conditions require a full and proper clinical examination and a full social history. 
  • Patients who are apyrexial with the 5D of botulism (Diplopia, Dysarthria, Dysphagia, Dyspnoea, Descending paralysis) should be treated as having botulism until proven otherwise. 
  • Early recognition and initiation of mechanical ventilation is key to survival. 

Further Reading