Tick

Question 1

lyme disease

Answer 1

Deer tick
borreilia burgdorferi
hyperendemic regions of eastern US

Question 2

RMSF

Answer 2

dog tick
-rickettsia rickettsia
trophism for vascular endothelial cells

Question 3

ehrilichiosis

Answer 3

lone star tick

-ehrlichia chaffeensis

Question 4

stage 1 lyme disease

Answer 4

Localized (incubation 3-32 days)

Rash (Erythema migrans)

Question 5

stage 2 lyme disease

Answer 5

Disseminated
	Multiple annular skin lesions
	Meningitis (headache, fever, stiff neck)
	Cranial neuritis (Cranial Nerve 7)
	Carditis (AV block)
	Arthralgia

Question 6

stage 3 lyme disease

Answer 6

Persistent
Oligoarticular arthritis (knee joints)
Encephalopathy (mood, memory, sleep disturbance)
Axonal Polyneuropathy (tingling feet, weakness)
Acrodermatitis

Question 7

rashes of lyme disease

Answer 7

“target rash” or bulls eye rash

-central clearing and necrotic center

Question 8

chronic lyme disease

Answer 8

• Pain syndrome (arthralgias)
  
  • chronic fatigue
  • neurocognitive symptoms
• Symptoms occur for years after eradication of infection.
• Symptoms may be indistinguishable from chronic fatigue syndrome, fibromyalgia.

Question 9

testing for lyme disease

Answer 9

serology: IgM and IgG
- often retrospective diagnosis using paired sera (acute and convalescent, draw at presentation and 2-4 weeks later)
- ELISA with Western blot verification- similar to older HIV testing methods
- PCR of joint fluid from arthrocentesis done in patient with arthritis
- PCR has low sensitivity in CSF

Question 10

treatment for lyme disease

Answer 10

doxycycline

Question 11

tick prevention tips

Answer 11

• Examine self after potential exposure, remove ticks
  
  • Use insecticides with DEET
  • Tuck pants into socks
  • Pre-treat clothes with permethrin insecticides
  • Insect-Shield clothing

Question 12

incubation time of RMSF

Answer 12

1 week

Question 13

basic pathophsyiology of RMSF

Answer 13

vasculitis
Increased vascular permeability
	Edema, hypovolemia
	Hyponatremia d/t compensatory ADH release
	Thrombocytopenia is common
	DIC is rare

Question 14

clinical presentation of RMSF

Answer 14

Triad: fever, rash, history tick exposure 
Symptoms
		fever
		headache
		malaise 
		myalgia

Question 15

how does rash evolve in RMSF

Answer 15

Progresses to vasculitic rash

- petechiae
- may involve palms and soles - does not appear until several days after onset of fever - does not bleach

Question 16

some more severe symptoms of RMSF

Answer 16

Hypovolemia, hypotension, fluid third spacing
Respiratory failure
Cardiac Dysrhythmia
CNS symptoms- confusion, lethargy, encephalopathy
ATN (acute tubular necrosis)
Shock
Elevated transaminases- acute hepatitis/liver failure

Question 17

lab testing for RMSF

Answer 17

Thrombocytopenia (low platelets)
Hyponatremia (low sodium)
Azotemia (increased BUN, potentially increased Cr if ATN develops)

Skin biopsy of lesion with direct immunofluorescence staining (obtain before or within 12 hours of antibiotic therapy)

Question 18

serology testing for RMSF

Answer 18

Serologic testing of IgM and IgG (first set of sera after five days of illness, second set 14-21 d after symptom onset)

Question 19

what are common ways for physicians to miss RMSF diagnosis

Answer 19

●Absence of a skin rash
●Presentation within the first three days of illness
●Presentation between 1 August and 30 April
-can be fatal if delayed treatment

Question 20

drugs of choice for RMSF

Answer 20

-Doxycycline is drug of choice in adults and children
Except for pregnant women
Doxycycline can cause dental staining in children <9 yrs old, but the risk is minimal if a short course is used.
Risk of bad outcome with RMSF outweighs risk of side effects from drug.

-Chloramphenicol is treatment of choice in pregnant 
women
	-difficult to obtain
	-less effective
	-in some cases benefits of doxycycline 
		outweigh risks in pregnancy

Question 21

incubation period of ehrilichiosis

Answer 21

8 days

Question 22

symptoms of ehrilichiosis

Answer 22

Fever
Headache
Myalgias

Question 23

lab findings of ehrilichiosis

Answer 23

Leukopenia
Thrombocytopenia
Elevated transaminases

Question 24

treatment of ehrilichiosis

Answer 24

doxycycline

Question 25

most severe malaria

Answer 25

P. falciparum - high parasitemia - end organ damage and death can occur

Question 26

less severe malarais

Answer 26

P. ovale, vivax( can have end organ damage), malariae

Question 27

patients with rash, fever and tick exposure can possible have

Answer 27

``` Meningococcal Disease Tick borne disease- RMSF Enteroviral disease Secondary Syphilis Rubella Drug eruption Kawasaki disease Coxsackie virus (hand foot and mouth disease) ```

Question 28

Key points after bite from infected mosquito

Answer 28

1. Plasmodium sporozoites have trophism for hepatocytes 2. Asexual reproduction in hepatocytes 3. Release into bloodstream 4. Hijacking of RBC and degradation of hemoglobin, formation of ring forms 5. Lyse RBC and release merozoites to invade more RBC, or gametocytes to reinfect mosquitoes {hemolytic anemia - > direct hyperbilirubinemia = jaundice} 6. P vivax and P ovale can produce dormant hypnozoites in hepatocytes, can reactivate in 3-12 months

Question 29

clinical features of malaria

Answer 29

Exposure to endemic area Lack of prophylactic treatment used by travelers Headache, fatigue, myalgias, abdominal pain FEVER

Question 30

what usually suggests P. falciparum

Answer 30

-Seizures suggest P falciparum infection | Paroxysmal chills, fever, rigors suggest P vivax or ovale (hepatic sequestration and re-release)

Question 31

physical findings of malaria

Answer 31

``` Fever Mild anemia Mild hepatomegaly Mild icterus (jaundice) Palpable spleen rash-> unusual, think other diagnosis ```

Question 32

what can P. falciparum do to CNS

Answer 32

Can cause sequestration and agglutination in vasculature, including CNS

Question 33

severe symptoms from P. falciparum

Answer 33

``` Cerebral malaria (seizures, encephalopathy, coma) Hypoglycemia (poor prognostic sign. Due to decreased hepatic gluconeogenesis and increased systemic glucose utilization) Metabolic acidosis (due to hypoperfusion, lactic acidemia) Noncardiogenic pulmonary edema (ARDS= adult respiratory distress syndrome) Renal impairment (ATN) Hematologic abnormalities (anemia) Liver dysfunction (cholestasis, acute hepatitis) ```

Question 34

diagnostic testing for malaria

Answer 34

Light microscopy of Giemsa-stained blood smear Thick and Thin blood smears- pathologist eval for ring forms and estimation of parasite load Thick blood smears concentrate parasites, increases diagnostic sensitivity -rapid diagnostic testing: antigen detection

Question 35

lab findings from malaria

Answer 35

Normocytic normochromic anemia | Increased acute phase reactants (ESR= sed rate, CRP= c-reactive protein)

Question 36

treatment for malaria

Answer 36

For non-falciparum malaria (chloroquine sensitive) | Chloroquine is treatment of choice

Question 37

treatment for P. falciparum

Answer 37

If chloroquine sensitivity is a certainty, chloroquine | If any question about chloroquine sensitivity, Arteminsin-based combinations are preferred

Question 38

preventive drugs for malaria

Answer 38

Malarone- easy to tolerate, short lead up and follow up, generic, inexpensive Doxycycline- was inexpensive Chloroquine- generic, inexpensive, easy to tolerate

Question 39

bad prevention drugs for malaria

Answer 39

Mefloquine – CNS side effects

Question 40

non-pharmacological prevention of malaria

Answer 40

Mosquito tents Insect repellents Preventive treatment in travelers