Infantile botulism is a form of botulism that affects children less than a year old. Risk factors include ingestion of honey (or other products) and exposure to construction sites in which Clostridium botulinum spores may be found. The clinical presentation is significant for descending paralysis, acute hypotonia, lethargy, ptosis, and other neurologic manifestations. The diagnosis is clinical and relies upon the history, risk factors, and physical exam. Detection of the spore or toxins in the stool is one method for confirmation.
Infant botulism is one of 4 types of botulism along with foodborne, wound and intestinal . Although rare, infant botulism is the most predominant type in the United States, where it has been traditionally associated with the ingestion of honey   . However, the etiology and source of spores remain unknown in the majority of American cases . Other sources include corn syrup, grape molasses , infant cereal formulas, infant powdered milk, and medicinal plants . Spores may also originate from soil and dust found in construction areas .
Infantile botulism occurs in children less than a year old because this age group has low gastric acid production, a smaller pool of flora, and an immature immune system, all of which render them vulnerable to toxin production following the ingestion of Clostridium botulinum spores . The botulinum toxin inhibits the release of acetylcholine at the neuromuscular junction , which is the mechanism of action responsible for the signs and symptoms observed.
The clinical manifestations of infant botulism include descending paralysis, constipation (which may precede other symptoms), hypotonia, lethargy, weak sucking, weak crying, irritability, and weakness of the bilateral extremities and face   . Note that a clinical presentation of acute hypotonia should raise suspicion for this condition . Note that, in many cases, descending paralysis may be absent.
Patients may present with hypoventilation that ultimately progresses to respiratory failure requiring endotracheal intubation  . Specifically, 60% of the infants eventually require mechanical ventilation as the disease advances . Additionally, impaired gag reflex can cause aspiration.
Infants with infant botulism appear floppy . On the neurologic exam, remarkable findings include hypotonia, reduced deep tendon reflexes, ptosis, sluggish pupils, reduced gag reflex, and significant head lag    . Patients may also exhibit signs of respiratory distress. They typically do not have a fever.
The diagnosis of infant botulism is largely based on the patient's clinical presentation, medical history, risk factors, and physical exam. A crucial component of the workup includes a history of all patient intake with regards to honey, baby formulas and powdered milk, plants, and other sources of spore exposure. Additionally, the clinician should inquire whether family members were recently ill . Note that this diagnosis should still be considered in patients who lack exposure to honey or construction locations . Prompt treatment is paramount for these patients and this relies on recognition of the signs and a high index of suspicion .
Confirmation is best made through the detection of botulinum toxin or spores in the stool whereas serum testing for toxins is not as sensitive . Also, isolation of the implicated pathogen in the stool is another method.
To help rule out differential diagnoses and attain a complete clinical picture, laboratory tests such as a complete blood count (CBC), complete metabolic panel (CMP) which includes electrolyte levels, and spinal fluid analysis should be obtained .
If abnormal, findings will feature a pattern of short-lasting, small-amplitude motor-unit action potentials in abundance . This is not pathognomonic for infant botulism as it occurs in other neurological diseases as well  .