Lyme Disease

Question 1

What is the primary hosts of black legged ticks

Answer 1

Mice and smaller rodents, birds and white tailed deer

Question 2

Do dogs spread Lyme disease

Answer 2

No. Although they can carry ticks into the home there is no evidence that they spread infection to ppl

Question 3

What is the age of kids most frequently affected with Lyme disease

Answer 3

5-9 years of age

And older adults 55-59 years

Question 4

Does Lyme disease in a pregnant mom affect the fetus?

Answer 4

There is no evidence of this.

Question 5

Which stage of the tick life cycle are most responsible for disease?

Answer 5

Nymphs

Their small size hinders detection

Question 6

How long do ticks have to feed to cause Lyme disease

Answer 6

Likely longer than 36 hours

If removed within 24-36 hours it is likely not going to cause disease

They can feed for five days!

Question 7

How common is Lyme disease in Canada

Answer 7

> 500 cases in Canada in 2013

Question 8

What are the different stages of Lyme disease?

Answer 8

Early localised or disseminated

Late

Question 9

What are the clinical manifestations of early localised disease and when does it occur relative to the tick bite

Answer 9

Occur within 7-14 days

Erythema migrans at the site of the tick bite. This rapidly expands centrifugally. Sometimes has a central clearing. > 5cm

Systemic symptoms: fever, malaise, headache, mild neck stiffness, myalgia and arthralgia

Question 10

Without treatment, will early Lyme disease resolve?

Answer 10

Yes!

Without treatment it will resolve within 4 weeks.

Question 11

What are the clinical manifestations of early disseminated disease and when does it occur?

Answer 11

Occurs several weeks after the tick bite.

Rash: multiple erythema migran lesions. Smaller then primary lesion

Acute neurological signs: facial palsy, (CN VI and VII) papillodema, lymphocytic meningitis.

Lyme carditis is rare (heart block)

Question 12

What are the clinical manifestations of late disease?

When does it occur?

Answer 12

Pauciarticular arthritis, large joints especially the knee

Manifest weeks to months later

Rarely have peripheral neuropathy or CNS findings.

Question 13

How is the diagnosis of Lyme disease made?

Answer 13

Early localised: clinically
NB the antibodies can take four weeks to become positive

Early disseminated and late: ELISA ➡️ western blot

Question 14

Why do you need to do two tierd testing?

Answer 14

ELISA is highly sensitive but poor specificity (yields false positive)
Also positive with autoimmune disease and other viral and spirichete infection.

Western blot is highly specific but poorly sensitive

Question 15

How do you monitor treatment?

Answer 15

Clinically.

Antibodies are not reliable to follow to monitor for improvement.

Question 16

What is not used in testing?

Answer 16

Joint aspirate for antibodies and urine antigen.

Question 17

How do you diagnose CNS meningitis?

Answer 17

LP CSF for IgM and IgG

Question 18

How do you treat Lyme disease ?

Answer 18

Options: 
Doxycycline 4mg/kg 
Amoxicillin 50mg/kg/day
Cefuroxime 30mg/kg
IV ceftriaxone 50-75 mg/kg
IV Penicillin 200090 units/kg/day

Question 19

How long do you treat for?

Answer 19

Depends in the type. 
EM 14-21
Isolated facial nerve palsy 14-21
Multiple EM 21
Arthritis 28
Recurrent arthritis 28
Heart block or carditis 14-21 IV
Meningitis 14 IV 
Encephalitis 14-28 days IV

Question 20

How many ppl have residual symptoms with arthritis

Answer 20

1/3 have residual synovitis and joint swelling

Question 21

What is jarisch herxheimer reaction?

Answer 21

Fever headache myalgia and an aggravated clinical picture lasting

Question 22

What is post treatment Lyme disease syndrome and how common is it

Answer 22

Lingering fatigue and joint and muscle aches
10-20%

? Residual damage to tissues and immune system.

Question 23

Do longer courses of antibiotics prevent PTLDS?

Answer 23

No.

Question 24

How do you remove a tick?

Answer 24

Tweezers
Steady pressure upwards
Do to twist or jerk
Clean with rubbing alcohol 
Keep in plastic bag

Question 25

Can you prevent Lyme disease

Answer 25

Good landscaping if nearby woods
DEET 20-30%
Icarian repellant
Full body check

Question 26

Should there be post exposure prophylaxis?

Answer 26

Yes. In known endemic areas

Who: tick, within 72 hours of removal, even if attached > 36 hours.

Doxycycline 200 mg x1

Question 27

Who should not be given doxycycline?

Answer 27

Children

Question 28

If your patient has worsening symptoms after initiated antimicrobials what does he have and what do you do?

Answer 28

Jarisch-herxheimer reaction

NSAIDs and continue ABx

Question 29

What causes Lyme disease and how is it transmitted?

Answer 29

Infection with Borrelia burgdorferi transmitted to humans through the bite of an infected black legged tick, Ixodes scapularis and Ixodes pacificus