Hello, i have these small bumps on the top of my left hand and they are a bit itchy and appeared overnight. any idea what this is?

No: Sounds like an allergy or skin inflammation- you can try gentle 0.5% Hydrocortisone cream appplied as a thin layer : 2-3 times daily; however, if not improving see you physician for an exam.

Skin issues: There could be a number of reasons this is happening, from an allergic reaction to something that you were exposed to, to bites from insects etc. If there are other people at home who have similar issues, it could be some insect bite. Have your physician take a look at the actual bumps as it helps us figure out what they are. Hope this helps