Brown Recluse Spider?
If you live in North America then there is a chance that the spider that bit you is a Brown Recluse whose venom actually eats away at the flesh of a human which gives off the appearance of a small cigarette burn. Whether you are an adult or a child who has been bitten, you should see your doctor as soon as possible. They will be able to tell you what you can do to help it to heal. They will probably prescribe a cream or possibly antibiotics to combat any poison that is in your system. The cream or ointment will come with its own instructions that you must follow exactly in order for the healing process to be done properly.
Black Widow Spider?
Black Widow spiders will leave a mark that looks like a small bulls eye, which will also be accompanied with a lot of discomfort or quite a bit of pain around the area. Although Black Widows are not usually fatal unless you are a small child, you should still see an doctor as soon as possible, as they can cause some damage.
What To Do Next?
The majority of spiders that bite will usually just leave a small red bump that will look like a target or bulls eye. This area will be quite tender and sometimes quite painful after the bite. A lot of them will usually itch to a certain extent. If you notice a spider bite then you should see your doctor as soon as possible so that they will be able to figure out what type of bite it is and how best to treat it.