Centipede bites

Centipede bites may cause poisoning as a result of venom released from the fangs.


Causes

Centipedes are in the class Myriapoda and are venomous, terrestrial, multipodal arthropods, and often live in hot and humid places in summer. There are more than 2,800 species of centipedes discovered in the world.

Figure 1 Centipede

Intoxication mechanism

There are a pair of fangs connected to the venom glands, which can secrete venomous components, including histamine-like substances, hemolytic proteins, tyrosine, formic acid, fatty oil, and cholesterol. After being bitten by a centipede, its venom glands secrete a large amount of venom, and inject the venom into the skin of the bitten human through the fangs, which can cause local damage or allergic reactions. In severe cases, rhabdomyolysis and even acute renal failure may occur. Occasionally, there may be anaphylactic shock, as a result of histamine-like substances acting on microvessels contributing to microvascular spasm, dilation, and plasma exudation and eventually leading to microcirculation disorders. In severe cases, there may be death. The clinical severity is related to the size of the centipede and the amount of venom injected during the bite.


Signs and Symptoms

There are acute onset and rapid development. There are only local manifestations if being bitten by small or medium-sized centipedes. Two petechiae may occur on the skin, and there are redness, swelling, burning sensation, severe pain, scratchiness, lymphangitis, and lymphadenopathy in most patients. In severe cases, vesicles, petechiae, and tissue necrosis even occur, and sometimes purpura is present on the affected limb. Clinical manifestations subside within few days. Without effective treatment, some patients present with local swelling and pruritus 1 month after being bitten.

Video 1 Centipede bites

If being bitten by a large centipede with more venom, in addition to local presentations, systemic symptoms of poisoning such as fever, nausea, vomiting, dizziness, headache, palpitations, delirium, and convulsions may occur. In severe cases, manifestations of acute renal failure, such as oliguria, anuria, and proteinuria may be present. Small amounts of patients may present anaphylactic shock. Acute myocardial infarction can occur in very few patients.


Diagnosis

If there are a history of being bitten by a centipede and clinical manifestations, the condition can be diagnosed.


Treatment

The bite site should be washed with soapy water or clear water immediately.

Topical 3% dilute ammonia solution or 5% - 10% sodium bicarbonate solution is appropriate.

Ice compress can be applied to obvious local swelling.

Local wet compresses with the mixture of dexamethasone, lidocaine, and normal saline can be administered for those with severe redness, swelling, and pain.

Secondary lymphadenitis or lymphangitis should be given anti-infective treatment.

Anti-allergy and anti-shock therapy may be needed.