Pediculosis

Question 1

Three types of lice that infect humans

Answer 1

Pediculus humans capitis (head louse)
Pediculus humans corporis (body louse)
Phthirus pubis (pubic/crab louse)

Question 2

What causes the pruritus associated with head lice infection

Answer 2

Sensitization to the lice toxin, feces, &/ body parts which takes 3 weeks to 8mo to develop

Question 3

What infections can body louse spread in humans

Answer 3

Typhus, relapsing fever, and trench fever

Question 4

Which is the only type of louse where African Americans as frequently affected as Caucasians

Answer 4

Pubic lice

Question 5

Associated primary lesion in pubic lice infection

Answer 5

Maculae ceruleae which are gray-blue macules in the groin and at distant sites

Question 6

Tx options

Answer 6

For all types: first line is permethrin 1% or malathion

• apply permethrin to dry hair and rinse after 10min (repeat 1 week later)
• Malathion is useful in resistant cases and left on for 8-12 hrs
• rarely, bactrim can be used if nothing else working