Sunday, August 19, 2018

Answer to Case 507

Answer: Male Pediculus humanus, likely P. h. capitis (clinical correlation required) - or - as Blaine and Florida Fan note - a booger bugger beastie!

As Idzi mentioned, it is not possible to tell P. h. humanus and P. h. capitis apart by morphology alone since there is significant overlap in sizes between the 2 otherwise identical subspecies.

Richard, Florida Fan and Idzi nicely discussed the likely route of introduction into the nostril: little fingers, or possibly even inhalation. It makes me wonder though - could the lice ever live on nostril hair? 

As a review, here are some of the key identifying features of Pediculus humanus:

  • Small body (1-2 mm long)
  • 6 legs 
  • Dorsoventrally-flattened
  • Wingless
  • Raptorial (grasping) claws
  • Fused thorax, distinct from the head (with antennae) and abdomen
  • Enlongated body
Thanks again to Kamran for donating this case!

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