Pathophys-Day 3 Bugs, Bites, Stings

Question 1

Chagas disease acute presentation

Answer 1

Local erythema and LAD
Romana sign - painless edema of palpebrae
Fever, malaise, anorexia, edema extremity

Question 2

Chagas disease chronic presentation

Answer 2

Years to decades later
Cardiac and GI manifestations:
Failure arrythmia, megacolon etc

Question 3

Treatment for Chaas

Answer 3

Nifurtimox and benzimidazole

Question 4

American trypanosomiasis (Chagas disease) is caused by?

Answer 4

Reduvid bug carrying T cruzi

Question 5

African sleeping sickness caused by?

Answer 5

Tsetse flies carrying T brucei

Question 6

African tryp infection compared to american?

Answer 6

Direct fly bite injects trypanosome into skin which migrates to blood stream

Question 7

African trypanosomiasis presentation

Answer 7

Chancre
LAD
Neurologic manifestations - irritable, personality, daytime somnolence, insomnia

Question 8

African tryp treatment

Answer 8

Suramin DOC for early
Pentamidine
Eflornithine - both hemolymph and CNS dz

Question 9

Where is onchocerciasis endemic?

Answer 9

Sub-saharan Africa (part) and parts of South America

Question 10

Onchocerciasis presentation?

Answer 10

Subq nodules located on top of bony prominences
Intermittent severe itching
Thickening of the skin
Conjunctivitis, glaucoma, and blindness

Question 11

Onchocerciasis treatment

Answer 11

ivermectin

nodulectomy

Question 12

What is the Mazzotti reaction?

Answer 12

Potentially severe reaction to DEC treatment for onchocerciasis. So common that it is diagnostic for onchocerciasis (skin patch test).

Help diff from syphillis?

Question 13

What is tungiasis?

Answer 13

Burrowing flea infestation of skin that causes nodules and erythema

Question 14

Tungiasis treatment

Answer 14

Early: remove flea with needle
Late: curettage, excision
Topical creams
Niridazole
Tetanus prophylaxis
Prevention: shoes, don't sit on beach

Question 15

Cutaneous myiasis what is it?

Answer 15

Botfly deposits Dermatobia hominis larvae in skin which inhabits wound causing dermis to boil

Question 16

What is the best treatment for cutaneous myiasis?

Answer 16

BACON

Do not remove forcibly!

Question 17

Botfly localized to

Answer 17

Belize etc

Question 18

Cimicids are also known as

Answer 18

bed bugs

Question 19

What is the characteristic bedbug bite pattern?

Answer 19

Breakfast, lunch, dinner linear 3

Question 20

Bedbugs can spread/worsen these diseases

Answer 20

Hep B and Chagas (vector)

Asthma (feces)

Question 21

Pediculosis capitis aka

Answer 21

head lice

Question 22

pediculosis corporis

Answer 22

body lice

Question 23

phthiriasis pubic

Answer 23

pubic lice

Question 24

Lice facts

Answer 24

Live 2 days off of host
Live 1 month
Direct contact spread
Treat 1% permethrin 10 min

Question 25

Body lice are vectors for:

Answer 25

``` Typhus (rickettsia prowazekii) Trench fever (Bartonella) Relapsing fever (Borrelia) ```

Question 26

Maculae cerulae may be caused by:

Answer 26

body and pubic lice

Question 27

Do scabies act as vectors?

Answer 27

No

Question 28

Scabies is caused by

Answer 28

Sarcoptes Scabiei

Question 29

Where are scabies most commonly found on the body in adults?

Answer 29

Interwebs Wrist flexor surfaces Elbows Penis, scrotum, umbilicus

Question 30

Where are scabies most commonly found on the body in infants?

Answer 30

Head and face

Question 31

Scabies dx

Answer 31

Skin scrape showing either mites, feces, or eggs

Question 32

Scabies treatment

Answer 32

Permethrin 5% to all skin 2x wk apart or sulfur 5-10% in petrolatum 3 nights

Question 33

How long is the dormant period of a scabies infection?

Answer 33

1 month plus because you have to mount an immune response to it

Question 34

Brown recluse pathogenesis

Answer 34

Sphingomyelinase D is the major toxin Interacts with serum amyloid Also hyaluronidase allows eschar to follow gravity

Question 35

Brown recluse bite tx

Answer 35

None really, maybe prednisone | Ice

Question 36

Hobo spider biet S/S

Answer 36

Headache, nausea, fatigue Possibly necrosis and amputation Hemolysis and thrombocytopenia possible

Question 37

Black widow bite pres

Answer 37

Initial: erythema, sweating ``` Worst: abdominal pain Muscle spasms/paralysis HA Nausea Hypertension ```

Question 38

Black widow bite treatment

Answer 38

IV Ca gluconate Analgesics Antivenin if severe

Question 39

Black widow pathogenesis

Answer 39

depletion of acetylcholine at motor nerve endings and release of catecholamines at adrenergic endings