As soon as the kid gets bitten, wash that part up with water and soap. Wash the part regularly, several times a day to keep off infection. keeping it clean is essential to a quick heal.
Placing an ice pack over the bite will relieve any swelling and also take away pain.
As you clean the part, pat it dry with a clean towel or tissue and then apply an antibiotic ointment with clean hands. This antibiotic will ward off any infection that will potentially develop at the hurt part. Infections attack weak parts and at this time, the bitten part is susceptible to them. Spider bite creams are readily available in the market and should be in your first aid box all time.
You can also give a pain killer to the kid if the pain persists. However, if the kid is experiencing high level of pain, it is best to take him to a doctor to be on the safe side. However, any medicine that you give the child should be age appropriate. Medicines like acetaminophen or ibuprofen are effective painkillers.
Consult a doctor:
If the above remedies do not work, you will have to take the child to the doctor. If you are not sure of the type of spider which bit your child, it is best to take him/her immediately. Spider bites also instigate allergic reactions. Be on the look for this. Examine the child closely after the bite and take a decision based on the symptoms.