When we think of spider bites we think of the Black Widow Spider and the infamous Kiss of Death. However the truth is that 98% of all spider bites are harmless.
We are concerned about spider bites because some spiders release venom which is toxic to humans and in some cases the venom in spider bites will kill. The varieties of spiders which do not release venom are: Hackled orb-Weavers, Holarchaeidae, Uloboridae, and Mesothelae.
The spiders prey is mostly insects, even other spiders, therefore generally speaking spiders do not have mouths big enough to pierce through human skin. Another factor to look at is that even if a human has been affected by spider bites, most spiders do not produce enough venom to do any serious harm.
There are two categories of venomous spider bites. The neurotoxic variety attack the nervous system but how the venom affects the human nervous system does depend upon the spider.
Lactrodectus spiders (Widow Spider) release a chemical compound called lactrotoxin which in turn produces a condition known as lactrodectism. This condition will release calcium ions that will trigger the neurotransmitter known as acetycholine. Once humans have been infected by the spider bites they will experience breathing problems and painful cramping.
In the case of the Australian funnel-web spider and mouse spider, their bite will stimulate neuron sodium pathways that interfere with human bodily function.
Spider bites from the Brazilian Wandering Spider will range from tiny painful pinpoint pricks to deathly envenomation due to level of serotonin released into the body.
Neucotic venom is the toxin produced by spiders in the Sicariidae family. The venom breaks down the skin cells with symptoms ranging from minor localized irritation, severe skin lesions, kidney failure, and even death. Spider bites from members of this family can produce ulcers on the skin tissue causing deep scaring that may take years to heal properly. The ulcers are itchy and painful and gangrene can set in. The venom can spread throughout the entire body within minutes of the bite.
The best treatment will be to act immediately upon realizing you have been bitten by a spider. Get emergency care from a professional. You will need to get to a hospital in hope to find qualified personnel with the expertise to diagnosis and treat spider bites. Where ever possible bring the spider in to the hospital with you. This will aid in the treatment plan and reduce misdiagnosis which no doubt could lead to severe consequences.
When the spider bites are minor in nature, treatment start by first letting the wound bled out to release the toxins, if and when the wound is large enough, applying an ice pack to reduce any swelling, applying an antiseptic to clean the exterior area of the wound and finally applying a topical ointment such as aloe vera to reduce pain.
Unfortunately no tried and true treatment is available for necrotic bites from venomous spiders. The treatments in use at present include; elevation of the affected area, application of ice packs, administering tetanus shots, antivenom agents, antihistamines, various antibiotics, oxygen, vosodilators, electric shock treatments, curettage and surgery.