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.
Begin taking your hormonal birth control. Once youâve filled your prescription, you can start using the method. If you are menstruating, you should wait until the end of your period to start these methods. Begin taking pills either on the day that you start your period or the Sunday after you start.