Tick Bites in Australia

reference – ASCIA + ETG

https://www.health.gov.au/sites/default/files/2022-11/management-of-tick-bites-in-australia_0.pdf

1. Epidemiology & Distribution

Ixodes holocyclus (scrub/paralysis tick) → accounts for ~95% of Australian tick bites.
Found along eastern seaboard, usually up to 30 km inland (can occur in pockets up to 100 km inland).
Distribution maps available on ASCIA website.

Ticks are arachnids (related to spiders) with 8 legs.

Life stages / size:

Larvae: ~1 mm, very small and hard to see.
Nymphs: ~2 mm.
Adults (before blood feed): ~4 mm.

Habitat & transmission:

Adult ticks attach to tips of grass blades and vegetation.
Transfer to hosts (animals or humans) when brushed against.

Preferred bite sites: commonly head, scalp, and neck.

Reactions:

Most common: local irritation, itching, swelling at bite site.
Usually not allergic in nature.

Geography:

Historically concentrated on the east coast of Australia, but now also found in some non-coastal areas.

Seasonality:

Risk of tick exposure exists all year round.

Ticks can cause:
- Persistent local reaction (“persistent arthropod reaction”).
- Systemic allergic effects (incl. anaphylaxis).
- Neurotoxic envenoming → tick paralysis.
- Transmission of rickettsial infections (Queensland tick typhus, spotted fevers).
- Transmission (rare) of Coxiella burnetii (Q fever).
- Mammalian meat allergy (α-Gal sensitisation).

2. Presentation

Tick bites are painless (saliva contains anaesthetic).
Often detected only when engorged (after 2+ days).
Favoured sites → moist/vascular areas (scalp, flexures).
Acute/short-term reactions:
- Anaphylaxis (rare but possible at first adult tick bite).
- Local erythema, swelling, itching, pain (delayed by days).
Systemic complications:
- Tick paralysis.
- Rickettsial infections (eschar, fever, systemic illness).
- Mammalian meat allergy (delayed food allergy).

3. Allergy & Anaphylaxis Risk

First adult tick bite may cause anaphylaxis.
Risk highest when tick is disturbed.
Fatal tick anaphylaxis is documented, though uncommon.
Prevention:
- Kill tick in situ before removal.
- Avoid tweezers or scratching.
Known tick allergy:
- Immediate hospital/ED referral for removal.
- Must carry adrenaline autoinjector and ASCIA Action Plan.

4. What NOT to Do

❌ Do not scratch itchy lesions without inspection in endemic areas.
❌ Do not squeeze, agitate, twist, or jerk tick → increases saliva/venom injection.
❌ Do not apply irritants (spirits, kerosene, oil, alcohol, nail polish, matches).
❌ Do not use tweezers/fingernails to pull live tick.
Mantras:
- “Household tweezers are tick squeezers.”
- “Freeze it, don’t squeeze it.”
- “Dab it, don’t grab it.”

5. Recommended Management

Adults Ticks (visible)

Freeze in situ with ether-containing spray (e.g., Tick Off®).
Allow tick to drop off naturally (usually within minutes–hours).
If remains attached → leave in place and refer urgently.

Small Ticks (larval/nymphal)

Apply permethrin cream (Lyclear®).
Dab twice, 1 min apart.
After 60–90 mins, scrape off with blunt scraper.
⚠️ Limited safety data in pregnancy/breastfeeding → seek pharmacist advice.

In Clinical Settings

If necessary, remove with fine blunt forceps after killing tick.
Ensure mouthparts not retained (risk of prolonged local reaction).
If incomplete removal or embedded → consider punch biopsy.

6. Tick Bite Reactions & Complications

A. Local Reactions

Common, often delayed.
Can persist days, esp. if head/mouthparts retained.
May mimic infection.
Warn patients about prolonged reaction risk.

B. Tick Paralysis

Tick must remain attached ≥4–5 days.
Clinical features:
- Ascending paralysis → leg weakness, ataxia, gait disturbance.
- Progression → upper limbs, trunk, neck.
- Facial/bulbar muscles → ptosis, dysarthria, stridor.
- Severe → respiratory muscle paralysis.
Children: important differential for acute ataxia.
Adults: may mimic Bell’s palsy.
Management:
- Remove tick.
- Observe and perform serial neuro exams for 48 hrs (paralysis may progress post-removal).
- Severe cases → intubation & mechanical ventilation.
- ⚠️ Antivenom no longer available.

C. Tick-Borne Infections

Require tick attachment ≥24 hrs.
Rickettsial infections → Queensland tick typhus, Flinders Island spotted fever, Australian spotted fever.
- May present with fever + eschar (black necrotic ulcer) at bite site.
- Treat with appropriate antibiotics (see ETG rickettsial guidance).
Q fever (Coxiella burnetii): rarely tick-borne (inhalation more common).
Lyme disease: not endemic to Australia, but imported cases possible.

D. Mammalian Meat Allergy (α-Gal Syndrome)

Tick bite sensitises to alpha-gal (carbohydrate in mammalian meat, milk, gelatin).
Symptoms:
- Delayed (3–6 hrs post ingestion).
- Urticaria, angioedema, abdominal pain, diarrhoea, anaphylaxis.
Can appear months after tick bite.
Consider in any patient with new delayed meat allergy.
Management:
- Referral to immunologist.
- Strict avoidance of mammalian meat/gelatin.
- Carry adrenaline autoinjector.

7. First Aid for Tick Anaphylaxis

Lay flat, elevate legs.
Administer adrenaline autoinjector immediately if symptoms present.
Call 000 (life-threatening emergency).
If alone → open door, call 000, use adrenaline, lie flat.

8. Key Clinical Takeaways

Tick bite is painless → check carefully in endemic areas.
Do not disturb the tick; kill in situ with freezing or permethrin.
Adult ticks → freeze.
Larvae/nymphs → permethrin.
Known tick allergy → hospital removal only.
Watch for:
- Prolonged local reactions (esp. if mouthparts retained).
- Anaphylaxis at first bite.
- Tick paralysis in children with acute ataxia.
- Rickettsial fever with eschar.
- Mammalian meat allergy (delayed, months later).