This could be because you're sensitive to the alkaline base on the weave or other hair. Some people think they are allergic to weaves or to synthetic hair but frequently they are just allergic to the alkaline base designed to make synthetic hair more shiny or softer. The solution is to wash the hair before use. This is how:
- Apple Cider Vinegar
- Castille Soap
- Pour luke warm water into a large plastic tub (e.g. a baby bathing tub) or your bath tub.
- Add a cup of apple cider vinegar.
- Add the hair neatly so that it doesn't get tangled and let it sit in the luke warm water for 15 minute. Squeeze the hair a little to release the alkaline base.
- Drain the water with the ACV in it from the tub and refill with fresh water.
- Add a little castile soap and wash the hair in that.
- Rinse in clean water then air dry it before use.
For a video demo watch the below clip. Skip to 0.50 on the time line to skip the intro.