The Sydney funnel-web spider (Atrax robustus) stands as one of the world’s most venomous spiders, primarily found within a 100-kilometer radius of Sydney, Australia. Its bite is capable of causing serious illness, and in untreated cases, can be fatal. Understanding its characteristics is important for rapid identification and appropriate response.
Physical Characteristics of the Bite
A bite from a Sydney funnel-web spider is very painful right away, often described as similar to a sharp prick or bee sting. This immediate intense pain is partly due to the spider’s large fangs, which can even pierce through certain fabrics.
Upon inspection, the bite site usually presents with clear fang marks, often appearing as two distinct punctures separated by several millimeters. While small, the marks are visible. Immediately around the puncture sites, localized redness and some swelling can develop. This initial reaction is distinct from the more widespread swelling and systemic symptoms that may follow as the venom spreads.
Developing Symptoms After a Bite
Following the initial bite, systemic symptoms can develop rapidly, often within minutes, though they may take up to an hour to manifest. Pain may spread from the bite site. Profuse sweating, accompanied by goosebumps (piloerection), is a hallmark sign of envenomation.
Other noticeable effects include increased salivation and tearing, alongside muscle twitching or spasms, which can affect various parts of the body. Individuals may also experience numbness around the mouth and difficulty breathing. As the venom progresses, elevated heart rate (tachycardia) and blood pressure (hypertension) are common, and in some cases, nausea and vomiting may occur. These symptoms can quickly escalate, potentially leading to confusion or even unconsciousness.
What to Do After a Bite
Prompt action is essential following a suspected Sydney funnel-web spider bite. The first step is to call emergency services immediately (000 in Australia). While awaiting medical assistance, apply a pressure immobilization bandage to the bitten limb.
This bandage should be applied firmly, similar to how one would strap a sprained ankle, starting directly over the bite site and extending upward along the entire limb. Also, immobilize the limb with a splint to restrict movement. Keep the person calm and still, as movement can accelerate venom spread through the lymphatic system. Avoid washing the bite site, cutting it, or attempting to suck out the venom, as these actions are not beneficial and can cause further harm. Rapid transport to the nearest hospital is necessary for the administration of antivenom, which has been highly effective in treating bites, with no reported deaths since its development in 1981.