I started experiencing this problem on my right hand six months after switching to Apple laptops and a MacBook Pro early 2011.
I only feel when using the trackpad, not an iphone and I dont own an iPad.
I bought an extra Apple trackpad and keyboard and put my laptop on a stand. It helps a little bit for some reason to use the external Apple trackpad, also because I'm using my index finger more on the external trackpad, which I'm not using the built-in trackpad.
But I'm considering getting a Magic Mouse also and perhaps the gloves that some people have talked about as I do think it is a problem of wear to the fingertips stemming from overuse of the trackpad, because it varies in degrees and I have never had any allergic reactions otherwise to anything else.
Sometimes I really feel it and other times I dont think about it. When it is really bad, I tend to use the very edge of my fingers, just below the nails. It's a bit awkward to hold the hand so upright, but it helps.. it might be the only place that I'm still not worn completely down on the fingertips.
So I looked into some software which might help not making me use the trackpad that often.
For navigating the screen there is a fantastic little utility called Shortcat: http://shortcatapp.com
It really has saved my bacon and made me not rely to heavily on the trackpad. It uses the accessibility features of OS X to quickly access anything on the screen just by using the keyboard. Besides aiding my fingertips it really speeds up navigating website etc. I can highly recommend it.
I tend to use it way more when using an external keyboard, but the trackpad is RIGHT THERE when I'm just on the laptop. This is my solution and it really works.
Shortcat is free while in beta but I really recommend buying it for 16 dollars as it is really helpful little tool.