Pubic Lice (Phthirus Pubis)

Question 1

What is the definition of pubic lice?

Answer 1

Blood sucking insects and specific parasites of human beings that are slightly smaller than head and body lice.

Question 2

How are pubic lice transmitted?

Answer 2

Close genital skin contact

Question 3

What is the pathophysiology of pubic lice?

Answer 3

Lice bite skin and feed on blood which causes itching
Female louse lay eggs on hair next to skin
Males live for 22 days, females for 17 days

Question 4

What are some clinical features of pubic lice?

Answer 4

Itchy red papules that are worse at night (usually 1-3 weeks after first infestation)
Blue macules may be seen at feeding sites
Minute dark brown specks of louse excreta sometimes seen on skin and underwear

Question 5

What are some investigations for pubic lice?

Answer 5

Diagnosis based on finding adult lice or eggs

Question 6

What is the management of pubic lice?

Answer 6

2x applications of malathion 0.5% aqueous lotion or permethrin 5% dermal cream, seven days apart