Pediculosis capitis

Question 1

Etiology. Subsecies. 
How many ova can it lay? 
feed every how many hours? 
size in mm? 
How many cm can it move in a day?

Answer 1

PediculusHumanusCapitis. Ses- ame seed size, 1 to 2 mm. Feed every 4 to 6 h. Move by grasping hairs close to scalp; can crawl up to 23 cm/day. Lice lay nits within 1 to 2 mm o scalp. Nits are ova within chitinous case.Younglicehatchwithin1week,passing through nymphal stages and maturing to adults overaperiodo 1week.One emalecanlay
50 to 150 ova during a 16-day li etime. Survive only or a ew hours o scalp

Question 2

Transmission

Answer 2

Head-to-head contact; shared hats, caps, brushes, combs; theater seats; pillows. Head louse is not a vector o in ectious disease

Question 3

Demography. White or black?

Answer 3

White.

Question 4

how many are infested in the US annually?

Answer 4

6 to 12 million persons in the United States are in ested annually.

Question 5

appearance of nits

Answer 5

Nits are the oval grayish-white egg capsules (1 mm long) rmly cemented to thehairs

Question 6

usually confined in what area of the scalp?

Answer 6

Post auricular and occipital

Question 7

Skin lesions

Answer 7

Bitereactions:Papularurticaria on the neck. Reactions related to immune sensitivity/tolerance. Secondary lesions: Eczema, excoriation, or lichen simplex chronicus on the occipital scalp and neck secondary to chronic scratching/rubbing. Secondary in ection with S. aureuso eczemaorexcoriations;mayextend onto the neck, orehead, ace, or ears. Posterior occipital lymphadenopathy.
DIFFERENTIAL DIAGNOSIS

Question 8

Microscopy

Answer 8

Nits 0.5-mm oval, whitish eggs (Fig. 28-9B). Nonviable nits show an absence
o anembryooroperculum.Louse.Insect
with six legs, 1 to 2 mm in length, wingless, translucent grayish-white body that is red when engorged with blood

Question 9

Tx

Topical and systemic

Answer 9

TOPICALLYAPPLIEDINSECTICIDES Permethrin, malathion, pyrethrin, ivermectin, and spi- nosad.
SYSTEMIC Oral ivermectin, levamisole, and albendazole.