It could potentially be irritation from trimming. I would suggest you have a shower, don't use soap or anything just warm water. Apply some non-scented lotion to the area - avoiding the entrance to your vagina. Then let things "air" out for a bit.
It is winter and the air is dry. That affects all parts of our body include out labia minora. If that doesn't work, I suggest seeing a doctor.
Hi there. Some women do get itching from shaving in the pubic area. The nerve endings go a little crazy then. However, you are describing your whole area that wouldn't be involved in that. do you have any discharge? Could this be a yeast infection?