Venomous Spiders

Facts and Information about the Venomous Spiders
All spiders are poisonous as that is how they catch and immobilise their prey. For their prey, their poison is deadly, but for humans, it can be no more than irritating, however some species of spiders are more dangerous to humans than others. Very few bites from spiders have resulted in people dieing though it has and does happen from time to time. Most spiders are non aggressive to humans and attack as a last resort, most would much rather run away and hide.

The Most deadly Spiders

Spider venom
The biggest concern with a spider bite is down to how medically significant the spiders venom is. The injection of the venom occurs during a bite and the spider can choose weather or not it does so. This having been said, not all spider bites involve venom being injected, if injected, the amount can very due to the size of the spider and the circumstances of the encounter that induced the bite. With only a few exceptions such as the camel spider, the bite its self is not a big concern for humans. Some bites may leave a larger wound were infections may be a concern, others involve spiders that eat prey that is already dead, this can lead to the transfer of infectious bacteria. It is generally the toxicity of the spiders venom that poses the highest risk to humans, there are several spiders that have a venom capable of killing a human with the amount the spider will typically inject when biting.
All spiders with the exception of the hackled orb weavers, the Holarchaeidae and the primitive Mesothelae are capable of producing venom. Bearing this in mind, only a small percentage of species have venom that poses a threat to people. Also, many spiders don't have mouthparts capable of puncturing human skin. Venom defined is a "Matter fatal or injurious to life" with only a few with sufficient toxicity to be harmful to humans and require medical attention and only a few known to produce fatalities.
A spiders venom works on two fundamental principles, one being a Neurotoxin that attacks the nervous system and the other, necrotic that attacks the tissue around the bite and in some cases, attacking vital organs and systems.

Treatment
The treatment of a spider bite depends on the spider its self, most spider bites are harmless to humans and don't require first aid. If bitten and experience extreme discomfort and require treatment, the spider if seen biting you may need to be identified by an expert, so that they can determine the species of the spider so the proper course of treatment can be administered. The best thing to do is to try and catch the spider, either alive or in a well preserved condition. A spider that has been flattened or left to decay may not be useful in a definite identification. The majority of medical responders are not trained to identify spiders and very few hospitals have spider experts on there staff. In general it is not possible to identify the type of spider responsible for a bite by observing the symptoms, contrary to media reports.
Unless a spider was seen biting some one, it can not be assumed it was a spider that has coursed any symptoms. Assuming the injury and side effects are from a spider bite can lead to misdiagnosis and mistreatment, leading to potentially life threatening consequences. Spiders are the most common source for false reports. A larger number of spider bites including ones from dangerous species, can be painless and go unnoticed if un observed. Symptoms from more dangerous species bites can manifest hours later, and by this time the spider will be long gone and identification impossible.
Treating a minor bite should be the same for any puncture wound, the wound should be first, encouraged to bleed to wash out any foreign debris. A topical antiseptic should be applied on the chance the bite may have introduced a virus or microbe beneath the skin level, were the antiseptic can penetrate. Observing the bite for a couple of days after is important so that if there are any signs of infection, medical help can be sought after. First aid may involve applying an icepack to control inflammation, applying aloe Vera is a good idea to help soothe the pain, if symptoms are sever, immediate medical care should be sought after.
If bitten by a widow spider, Australian venomous funnel web spider or a Brazilian wandering spider, immediate medical attention should be sought after. In a few cases, bite from these spiders can develop into medical emergency's. Also, medical attention should be sought if there is a severe allergic reaction.