Baking soda is a very old household remedy for simple itches, and it turns out to be relatively effective at this. It works by soothing the skin and reducing irritation. It can be used for simple skin itching that is not very severe and that does not persist for very long. However, if the itching is severe or persists, or if there is any sore or open area of the skin, it is best to ask advice from your primary care doctor
prior to using baking soda (or any other remedy).
In general, it would be a good idea to talk to your doctor about this itchy spot, regardless. This is because they will be able to take a look at it and diagnose what the likely cause is. Diagnosis is important, because it means that you can use a more specific treatment.
For example, if this is eczema
, which is a condition in which red, itchy, dry patches of skin develop on the hands, the definitive treatment would be good skin moisturizing and a topical steroid cream. On the other hand, if this is a fungal infection, the treatment would be an anti fungal cream.
Please ask your doctor to help you figure out what is going on. Good luck!