Arthropods

Question 1

List the arthropods:

Answer 1

• Sarcoptes scabei (itch mite)
• Cimex (bedbugs)
• Pediculus humanus capitis (head lice)
• Phthirus pubis (crab lice)

Question 2

Life cycle of Sarcoptes scabei?

Answer 2

Skin parasite of homeotherms (…I guess that’s us?)

Mate on skin…female then burrows :(
Eggs along tunnels hatch in a week

Question 3

Pathogenesis of Sarcoptes scabei?

Answer 3

Intense itch and rash due to tunneling and excretory products

Question 4

Diagnosis / Treatment of Sarcoptes scabei?

Answer 4

Skin between fingers, breasts, and penis - rash

5% permethrin topically

Question 5

Life cycle of Cimex? (bedbugs)

Answer 5

Hide in the day - follow CO2 gradient at night

- Can survive months without feeding

Question 6

Pathogenesis of Cimex?

Answer 6

Small, inflamed itchy bump at site of bite

Question 7

Diagnosis / Treatment of Cimex?

Answer 7

Inspect beds / vacuum mattresses / insecticides

Question 8

Life cycle of Pediculus humanus capitis? (head lice)

Answer 8

Live on hairy surface of scalp (eggs = nits); attach to base of hair shafts
- Hatch in 8-9 days and feed on blood

Question 9

Pathogenesis of Pediculus humanus capitis?

Answer 9

Intense itching with red papule (neck/scalp)

Question 10

Diagnosis / Treatment of Pediculus humanus capitis?

Answer 10

Direct inspection of hair

Shampoo with pediculicide, 1% Permethrin, comb out nits

Question 11

Life cycle of Phthirus pubis? (crab lice)

Answer 11

One month life cycle - 30 eggs, little larger than head lice

Question 12

Pathogenesis of Phthirus pubis?

Answer 12

Bites cause intense itching in pubic area

Question 13

Diagnosis / Treatment for Phthirus pubis?

Answer 13

1% Permethrin