Botulism: Difference between revisions

No edit summary
Line 11: Line 11:
# Respiratory Failure
# Respiratory Failure


===INFANT BOTULISM===
===Infant Botulism===
# no honey or corn syrup to < 1 yo
# no honey or corn syrup to < 1 yo
# most cases < 1 y/o, 90% < 6mo
# most cases < 1 y/o, 90% < 6mo

Revision as of 14:20, 15 March 2011

Background

  1. sporeforming,m obligate anaerobe, gram positive
  2. lethal dose 1 ng/kg
  3. 1 gm can kill 1 million people
  4. blocks release of Ach from presynaptic membrane
  5. experimental vaccine

Symptoms

  1. symmetric, desc. paralysis w/B/L cranial nerve neuropathies (diplopia, dysarthria, ptosis)
  2. GI sxs: N/V, pain, late constipation
  3. Respiratory Failure

Infant Botulism

  1. no honey or corn syrup to < 1 yo
  2. most cases < 1 y/o, 90% < 6mo
  3. most common form of botulism
  4. relative achlorhydia, poorly developed gut flora
  5. sxs from mild failure to thrive to sudden infant death
  6. drooling, ptosis, dilated/sluggish pupils, weak cry, feeding difficulties, constipation, resp arrest, poor head control, diminished muscle tone

WOUND BOTULISM

  1. black tar heroin, dirty wounds, C-section, tooth abscess, sinus infections
  2. incubation 10 days
  3. wound may appear benign
  4. GI sxs absent

Diagnosis

  1. clinically
  2. EMG studies: in botulism and Lambert-Eaton, few AcH released and muscle fibers don't reach threshold for contraction. With rapid nerve stim, can get enough AcH buildup in multiple muscle fibers to get "posttetanic facilitation."
  3. Nerve Conduction - normal in botulism (unlike GBS)

DDx

  1. Myasthenia Gravis - EMG findings and antibody studies will differentiate (decremental response to repetitive nerve stimulation). CAN see false positive improvement to Tensilon test in botulism
  2. Lambert-Eaton - spares resp muscles and primarily affects proximal lower limb muscles EMG findings similar to botulism (post-tetanic facilitation) but not identical
  3. Guillain -Barre - Miller Fisher variant has prominent ataxia & areflexia that isn't seen in botulism. Nerve conduction tests are also abnormal
  4. Poliomyelitis - usually have fever and asymmetric weakness. Ascending paralysis and CSF pleocytosis.
  5. Tick Paralysis - ascending paralysis, abnl nerve cond tests
  6. Diphtheria - proximal to distal spread of weakness 1-3 mo after fever and pharyngitis
  7. Hyperthyroidism
  8. Paralytic fish poisoning - tetrodotoxication (w/in 1 hr of fish eat)
  9. Mg, mushroom or chemical (arsenic,thallium, anticholinergic) or meds (antichol, aminogly)
  10. Sepsis

Workup

  1. Anaerobic cxs: emesis, gastric fluid, stool, food, wound, serum
  2. EPS - EMG shows decr amplitude with post-tetanic facilitation Nerve conduction normal

Treatment

  1. Ventilatory support: Intubate when VC < 30% predicted or < 12 cc/kg
  2. Foodbrone: antitoxin and AC, consider cathartics
  3. Infant: supportive care only, no benefit from antitoxin or Abx
  4. Wound: antitoxin, Td, wound irrigation & debridement even if appears well. Pen G 10-20 mill units/day