Several infectious skin diseases also cause a rash. These can be caused by a number of infections with bacteria or viruses, and infestations of mites within the skin. Some infectious skin diseases, such as scabies, are caused by mites that bore into the skin surface causing irritation and a localised rash.
Now, as for your question about when to start taking oral contraceptives, there's really no hard-and-fast rule about when to start taking birth control pills. Starting in the first few days of your cycle is the surest way to prevent inadvertently taking pills while you are pregnant.
How to start taking the pill. When you start taking the pill for the first time, you should take the first pill on the first day of your period. This way, you will be protected immediately and you wonât need to use an additional contraceptive to prevent pregnancy. You then need to take one pill every day. If you are on a mini pill, each pack will contain 28 pills. If you are on a combined pill, each pack will most likely contain 21 pills and you need to take a seven day break after each pack. It is also possible to start using the pill at a different point during your cycle. However, if you do not start taking it on the first day of your period you will need to use additional contraception for seven days. When you restart taking the pill after a break, you need to start the same way.