For the last 3 days I have had small bumps on both elbow and knee, area is red and when skin is pinched the bums turn white and you can notice a pin size hole in center of each bump. not painful at all but itchy, when i itch , some bleed very little. No puss. I have put Hydrocortisone Cream on it , helps itching but can t let clothing touch or it starts to itch. What is this? I have had it before on elbows only, never knees. 44 yrs old Male. No allergies to any pollen, food or drugs. Yes i know Rare and lucky. :) TY.