Centipedes are predatory arthropods, and the resulting injury is often mistakenly called a “bite.” The venom is injected through a pair of modified front legs, known as forcipules, which function like fangs to pierce the skin and introduce toxins into the tissue. The severity of this envenomation varies considerably, depending primarily on the size of the centipede species and the volume of venom injected, as well as the sensitivity of the person affected. The largest centipedes, particularly those in the Scolopendra genus, are responsible for the most painful and clinically significant human encounters.
Assessing the Pain Level
The immediate sensation following a centipede envenomation is typically a sharp, intense pain. This acute discomfort is often described as an immediate burning or searing feeling at the puncture site. For smaller centipede species, the initial pain is frequently compared to a severe bee or wasp sting, with the intensity peaking relatively quickly.
Larger centipedes, which can deliver a greater volume of venom, inflict a much more substantial and prolonged painful experience. The severity can be profound, sometimes described as a throbbing, relentless pain that radiates away from the two distinct puncture marks. This intense pain phase may last for several hours before it begins to gradually subside, though a dull ache may linger for a few days. The venom contains components that directly target pain receptors, accounting for the immediate and significant discomfort.
Secondary Symptoms and Local Reactions
Once the initial sharp pain has diminished, the affected area typically exhibits localized physical reactions. The most common signs are redness (erythema) and swelling (edema) around the envenomation site. This swelling is a direct response to the venom components and can sometimes extend into the surrounding limb.
The site may also become tender to the touch and feel warm, occasionally accompanied by a persistent itching or burning sensation. In some instances, minor systemic effects may occur, although these are rare and mild in most healthy adults. These symptoms can include a mild headache, anxiety, or slight dizziness that generally resolve without specific intervention.
Immediate Care and Medical Red Flags
Immediate treatment for a centipede envenomation should begin with thoroughly cleaning the puncture marks with soap and water to minimize the risk of secondary infection. Pain management should be initiated promptly, often beginning with the application of a cold compress or ice pack to the affected area. Applying ice helps to numb the site and constrict blood vessels, which can slow the spread of the venom.
The venom of many centipede species is thermolabile, meaning its toxic proteins can be broken down by heat. Submerging the affected limb in hot water—as warm as can be tolerated—for 30 minutes may help to denature the venom and provide significant pain relief. Over-the-counter pain relievers, such as acetaminophen or ibuprofen, can also be taken to manage the lingering discomfort. Seek immediate medical attention if you experience signs of a severe allergic reaction, such as difficulty breathing, throat swelling, widespread hives, or dizziness. Watch for red flags indicating infection, including fever, increasing pain after 48 hours, or red streaks radiating from the wound.