Pediculus humanus and Phthirus pubis (Lice)


Pediculus humanus and Phthirus pubis (Lice)

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A 15-year-old boy presents with pruritus over the chest and armpits, which developed two weeks ago. The patient is otherwise healthy. He lives in a boarding school and noticed several of his classmates had developed similar symptoms. Temperature is 37.0°C (98.6°F), pulse is 65/min, and blood pressure is 107/73 mmHg. Physical examination reveals oval-shaped yellowish structures attached to the axillary hair shafts. Multiple excoriations are noted over the torso. This patient is at increased risk for which of the following co-infections? 

External References

First Aid









disease vectors p. 147, 148

head/scalp p. 158

treatment p. 197

Mites/louse treatment p. 197

Relapsing fever

lice p. 158


Pediculus humanus and Phthirus pubis are types of lice that affect humans. Pediculus humanus is commonly known as head lice and primarily infects the scalp, whereas Phthirus pubis, is commonly known as pubic lice because it infests the pubic hair. Both types of lice are small parasitic insects that live close to the human skin sucking and feeding on blood. They can cause itching, redness, and irritation in the affected areas.

Pediculus humanus is most commonly spread through direct head-to-head contact or by sharing combs, and hats, whereas Phthirus pubis is commonly spread through sexual contact, but it can also be spread through close personal contact or by sharing personal items. Treatment for lice typically involves drugs like topical benzyl alcohol to kill the lice, and prevention requires proper body hygiene.


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