Stingers

There are three members of the arthropods that injure humans by the injection of venom. They are spiders, scorpions and the social insects (hymenoptera). Although the venom of these creatures is by itself only rarely fatal, an allergic reaction to the bite may be lethal.

Of the hundreds of species of scorpions, only 25 are poisonous to humans. In the US scorpion stings are predominately found in the Southwest. Some "hobbyists" keep scorpions as "pets" and therefore scorpion envenomations have been reported in all states. Scorpion venom acts as neurotoxin. It will cause paralysis in the small critters that are the scorpions prey. Localized pain, swelling, and numbness may occur in humans.

Most spiders produce venom that is transmitted through their fangs when they bite. Only 2 types of spiders cause serious problems in humans. Loxosceles reclusa, the brown recluse spider is found throughout most of the US. It likes basements, and was once the scourge of outhouses. Its venom is a tissue toxin. It may cause systemic symptoms such as nausea, malaise, and fever. Blood disorders may occur. Hemolysis (rupture of red blood cells), thrombocytopenia (loss of platelets) and DIC (severe loss of the ability of one's blood to clot) have all been reported. The most common consequence of a brown recluse spider bite is a skin ulcer. This loss of skin and underlying tissue can become quite large. It is very slow to heal and although many treatments are used, none has been shown to be consistently effective. The rare deaths from loxoscelism have occurred in children under seven and in the very old with preexisting medical problems.

Latrodectus mactans, the black widow spider possesses a venom that may cause painful reactions. Chills, fever, nausea and/or vomiting, sweats and elevation of the blood pressure have been observed. Severe muscle spasms may lead to abdominal, chest and back pains. The bite itself is so small that the symptoms may not be attributed to a spider bite. Although distressing, the symptoms are easily treated. Rarely, an anaphylactic allergic reaction to the bite may lead to a fatal outcome.

The hymenoptera include all the social insects: ants, bees, wasps, hornets and yellow jackets. The fire ant bite produces severe pain and itching at the location of the bite. A white pustule may form at the site. If a nest is disturbed, one is likely to suffer many bites. In the very small or weak person, the stress and toxicity of the bites can be lethal. Allergic reactions do occur in some. Secondary bacterial infection may also develop.

Honey bees, bumblebees, africanized (killer) bees, wasps and their brethren all inject a toxin when they sting. Most of the time this is a localized problem. Swelling, pain, redness and itching are immediate and self-limited. Honey and killer bee stinger are barbed and the stinger usually remains. The stinger should be carefully removed. The so-called killer bee's deadly reputation is from the number of stings, not the quality of it's venom. These bees tend to swarm and the poor victim often receives tens or hundreds of stings. The quantity of the venom may prove lethal in small children or those with a weakened cardiovascular system.

A bee or wasp sting may progress over 1 to 1.5 days with increasing localized swelling. This is more likely in the legs. Secondary bacterial infection of hymenoptera stings may occur with fever, increasing redness and tenderness, and red streaks (lymphangitis). Tetanus prophylaxis should be given if the patient has not been immunized in the prior 10 years. Stings in the mouth or throat may cause airway obstruction from localized swelling; bikers beware.

Allergic reactions to insect stings and bites are the real danger. Hives, wheezing, nausea and vomiting, chest pains and low blood pressure may be life threatening. Anaphylactic shock is the term given to this constellation of symptoms. Immediate treatments is necessary. Minutes count. Any patient that presents to the ER with an allergic reaction to a hymenoptera sting will be given treatment and strict post care instructions.

A preloaded adrenalin syringe (Epi-Pen) will be prescribed. It should be used immediately, if the patient receives any subsequent hymenoptera sting. The patient will also be referred to an allergist for specific testing and desensitization therapy. The specific species of insect venom can be identified and a series of allergy shots given. Just as it sounds, desensitization will decrease the risk of a life threatening reaction to insect venom.

Be prepared. Don't wear brightly colored clothes. Avoid applying perfumes when going outdoors.
Don't disturb hymenoptera nests. If you have a known insect allergy, CARRY YOUR EPI-PEN WITH YOU AT ALL TIMES. Stop and smell the roses, but watch out for bees.