Red, Itchy, Bumps On Skin, Gets After 6 At Night. Taking Benadryl

I have red itchy bumps on my skin that spreads on my thighs,back,hip,,and sometimes neck. It looks like hives. But I only get it after 6 a clock at night. Never during the day. I told my doctor and she does not know what it is. Sometimes it looks like scratches, but that could be from me itchy , I am not a adult either. I take Benadryl and it goes away by morning. And it doesn't always spread in the same places. it doesn't look gross or bloody. I am just sick of the itchy skin. Thank you