I've Been Developing Random Lump Masses On My Body Over

I've been developing random lump masses on my body over the course of the last few months. They appear in random places (but mostly reappearing either on my left wrist or by my spine) - they don't hurt. Only itch! Seldom red and blotchy and at other times, look like an allergic reaction (welt-like). They disappear within hours and rarely make it to the next day! I have yet to get blood work done. But I'm curious to know if the frequent coming and going is an indication of a greater health issue? Thank you