Botulism is a rare but serious condition caused by a toxin that attacks the body's nerves. Botulism may cause life-threatening symptoms. A type of bacteria called Clostridium botulinum produces the toxin. Botulism can occur as the result of food or wound contamination. The condition can also occur when bacterial spores grow in the intestines of infants. In rare cases, botulism can also be caused by medical treatment or bioterrorism.

Three common forms of botulism are:

  • Foodborne botulism. The harmful bacteria thrive and make the toxin in environments with little oxygen, such as in home-canned food.
  • Wound botulism. If these bacteria get into a cut, they can cause a dangerous infection that makes the toxin.
  • Infant botulism. This most generic form of botulism begins after spores of C. botulinum bacteria grow in a baby's intestinal tract. It typically occurs in babies between the ages of 2 months and 8 months. In rare cases, this form of intestinal botulism also affects adults.

Occasionally, botulism happens when too much botulinum toxin is injected for cosmetic or medical reasons. This rare form is called iatrogenic botulism. The term "iatrogenic" means an illness caused by medical exam or treatment.

Another rare form of botulism can occur from inhaling toxins. This may happen as the result of bioterrorism.

All forms of botulism can be fatal and are considered medical emergencies.


Foodborne botulism

Symptoms of foodborne botulism typically begin 12 to 36 hours after the toxin gets into your body. But depending on how much toxin you consumed, the start of symptoms may range from a few hours to a few days.

Symptoms of foodborne botulism include:

  • Trouble swallowing or speaking
  • Dry mouth
  • Facial weakness on both sides of the face
  • Blurred or double vision
  • Drooping eyelids
  • Trouble breathing
  • Nausea, vomiting and stomach cramps
  • Paralysis

Wound botulism

Symptoms of wound botulism appear about 10 days after the toxin enters your body. Wound botulism symptoms include:

  • Trouble swallowing or speaking
  • Facial weakness on both sides of the face
  • Blurred or double vision
  • Drooping eyelids
  • Trouble breathing
  • Paralysis

The area around the wound may not always appear swollen and show a change of color.

Infant botulism

Problems generally begin 18 to 36 hours after the toxin enters the baby's body. Symptoms include:

  • Constipation, which is often the first symptom
  • Floppy movements due to muscle weakness and trouble controlling the head
  • Weak cry
  • Irritability
  • Drooling
  • Drooping eyelids
  • Tiredness
  • Trouble sucking or feeding
  • Paralysis

Certain symptoms don't typically occur with botulism. For example, botulism doesn't usually raise blood pressure or heart rate or cause fever or confusion. Sometimes, though, wound botulism may cause fever.

Iatrogenic botulism

In iatrogenic botulism — when the toxin is injected for cosmetic or medical reasons — there have been rare occurrences of serious side effects. These may include headache, facial paralysis, and muscle weakness.

When to see a doctor

Seek urgent medical care if you suspect that you have botulism. Initial treatment increases your survival chances and lowers your risk of complications.

Getting medical care quickly can also alert public health officials about episodes of foodborne botulism. They may be able to keep other people from eating contaminated food. Keep in mind, though, that botulism can't spread from person to person.

An unusual cluster of botulism — especially in people with no clear link — that develops in about 12 to 48 hours may raise suspicion of bioterrorism.


Foodborne botulism

The typical source of foodborne botulism is homemade food that is improperly canned or preserved. These foods are typically fruits, vegetables, and fish. Other foods, such as spicy peppers (chiles), foil-wrapped baked potatoes and oil infused with garlic, may also be sources of botulism.

Wound botulism

When C. botulinum bacteria get into a wound, they can multiply and make toxin. The wound may be a cut that wasn't noticed. Or the wound may be caused by a traumatic injury or surgery.

Wound botulism has increased in recent decades in people who inject heroin, which can contain spores of the bacteria. In fact, this form of botulism is more common in people who inject black tar heroin.

Infant botulism

Babies get infant botulism when the bacteria spores get into their intestines and make toxin. In some cases, the source of infant botulism may be honey. But it's more likely to be exposure to soil contaminated with the bacteria. In rare cases, this form of intestinal botulism also affects adults.

Iatrogenic botulism

Rarely, botulism happens when too much botulinum toxin is injected for cosmetic reasons, such as removing wrinkles, or for medical reasons, such as treating migraines.


Because it affects muscle control throughout your body, botulinum toxin can cause many complications. The most immediate danger is that you won't be able to breathe. Being unable to breathe is a common cause of death in botulism. Other complications, which may need rehabilitation, may include:

  • Difficulty speaking
  • Trouble swallowing
  • Long-lasting weakness
  • Shortness of breath


Foodborne botulism

Use proper techniques when canning or preserving foods at home to make sure botulism germs are destroyed. It's also important to prepare and store food safely:

  • Pressure-cook home-canned foods at 250 degrees Fahrenheit (121 Celsius) for 20 to 100 minutes, depending on the food.
  • Think about boiling these foods for 10 minutes before serving them.
  • Don't eat preserved food if its container is bulging or if the food smells bad. But, taste and smell won't always give away the presence of C. botulinum. Some strains don't make food smell bad or taste unusual.
  • If you wrap potatoes in foil before baking, eat them hot. Loosen the foil and store the potatoes in the refrigerator — not at room temperature.
  • Store homemade oils infused with garlic or herbs in the refrigerator. Throw them out after four days.
  • Refrigerate canned foods after you open them.

Wound botulism

To prevent wound botulism and other serious bloodborne diseases, never inject or inhale street drugs. Keep wounds clean to prevent infection. If you think a wound is infected, seek medical treatment right away.

Infant botulism

To lower the risk of infant botulism, avoid giving honey — even a tiny taste — to children under the age of 1 year.

Iatrogenic botulism

To prevent iatrogenic botulism, be sure to go to a licensed health care provider for any cosmetic or medical procedures using various forms of botulinum toxin. They include onabotulinumtoxinA (Botox), abobotulinumtoxinA (Dysport) and others.

July 12, 2022
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