Insect bites

Assessment

Anaphylaxis

Insects (bees, wasps, ants, mosquitoes or sandflies)

• Insect bites and stings have the potential to cause an anaphylactic reaction. Treatment of anaphylaxis is a clinical priority.
• The treatment for most bites and stings is symptomatic.

Specific bites

In Australia, scorpions, centipedes, millipedes and caterpillars are not known to cause serious systemic envenomation, although some can cause intense local symptoms, such as pain, swelling and paraesthesia.

Anaphylaxis is not common from bites from these animals.

Examination

A-G clinical assessment.

Presentation:

• type of bite or sting if known
• time of bite or sting
• number of bites or stings
• location and size.

See Insect bites or marine stings - Adult ECAT protocol

See Bites, stings and rashes in the wilderness (NSW Health login required) from Therapeutic Guidelines.

Management

Avoid antibiotics to treat local reactions to bites, stings or plant injuries unless evidence of infection is present (e.g. cellulitis).

Review the tetanus immunisation status of patients. Consider tetanus prophylaxis.

Antihistamines may provide some relief from itch.

Insects

See Insect bites or marine stings - Adult ECAT protocol (Interventions and diagnostics)

Specific bites

• Scorpion and centipede bites: Ice and simple analgesia are usually sufficient to manage symptoms. Some patients report hot water alleviating pain.
• If itch is present, antihistamines can be used.
• Caterpillars can leave irritant hairs attached to skin. Remove with tweezers or adhesive tape.
• Millipedes can release irritant fluids that cause inflammation and marked brownish-purple hyperpigmentation. The hyperpigmentation is not harmful but can be mistaken for systemic conditions (such as ischaemia, trauma, meningococcaemia, bacterial endocarditis or cryoglobulinaemia). Clean affected skin thoroughly with soap and water, or alcohol. Pigmentation dissipates over weeks to months.

Patient information

Insect bites and stings
Source: Healthdirect