Bites: Lyme disease, animal bites, human bites

Question 1

Define/causes of Lyme disease?

Answer 1

An infectious condition caused by the spirochaete, Borrelia burgdorferi.

Transmitted via bite of an infected Ixodes tick -found in wooded areas.

Question 2

Presentation of lyme disease?

Answer 2

Disease presents in 3 stages.

Stage 1:
- localised disease, lasts several wks
- flu-like symptoms, regional lymphadenopathy
- circular, target-shaped lesion (Erythema chronicum migrans)
- blue patch on the earlobe, nipple or scrotum (Borrelia lymphocytoma)

Stage 2:
- early disseminated disease, lasts days to months
- flu-like symptoms
- cardiovascular involvement
- Neuroborreliosis
- Early painful arthritis

Stage 3:
- late disseminated disease, lasts months to years
- arthritis
- neurological disorders
- blue-red discoloration and swelling at extensor surfaces (Acrodermatitis chronica atrophicans)

Question 3

Diagnosis/IVx of lyme disease?

Answer 3

ELISA testing
- retest 3-4 weeks later if initial test is negative

Synovial fluid sample may be obtained for PCR Borrelia DNA testing.

Question 4

Management of lyme disease?

Answer 4

Suspected/confirmed:
- oral doxycycline (3wks) 1ST LINE
- oral amoxicillin (pregnant)
- Azithromycin -2ND LINE

• IV ceftriaxone (complicated case)

Question 5

Type of injury from dog bites? How infected? Management?

Answer 5

Crush injury to muscles, tendons, nerves.

Less likely to be infected.

Control bleeding
Consider tetanus/rabies vaccine.
Irrigate with germicidal.

Question 6

Type of injury from cat bites? How infected? Tx?

Answer 6

Puncture wound

More likely to be infected.

Offer prophylactic abx
- CO-AMOXICLAV

Control bleeding
Consider tetanus/rabies vaccine.
Irrigate with germicidal.

Question 7

Human bites -transmission, diagnosis, management?

Answer 7

If skin broken, blood-borne virus can transmit.

Clinical diagnosis
Serology testing for HBV, HCV, HIV.

Consider:
- prophylaxis immunisation (HBV)
- antiretrovirals (HIV)
- co-amoxiclav