Hi I have been waking up on a morning with red itchy bumps on my skin, they are usually on my hands and arms, however i have had one on my thigh and knee aswell, ive checked my mattress for bed bugs but i cant see any, ive washed my bedsheets and checked my duvet and pillows but i cant see anything. Its been happening a few times now for the last few weeks. I dont get them every morning , but they are really itchy and annoying and i just want to know what is causing this.