Hi Magpie, I too have had the skin reactions as described here, not on Riba, just have sensitive skin and it's more so on Tx and in the sun - even minimal exposure gives me red blotches or those little bumps.
If I have only minor ones on arms I rub in Lavender Essential Oil -it stops the inflammation and itchiness.
I personally wouldn't advise using Sorbolene - it is made from mineral oils e.g. paraffin oil; it is not a moisturiser but a barrier cream. This means the oils sit on the surface and create a layer on your skin that traps any moisture there and this can give temporary relief of dryness. But it doesn't penetrate the skin to moisturise it and hence the problem returns and in the long term it's believed to affect the skin's natural barrier reaction to environmental effects.
Moo Goo products, as Ariel suggested are good as they don't contain mineral oils.
Rubbing in Coconut oil, which a great for hydrating skin as it penetrates deeply, moisturises and softens skin. Also Jojoba, Rosehip, Sweet Almond (Cold-Pressed) or Avocado oils are all fantastic for dry, itchy skin problems and especially for sensitive skin issues.
I've been using an Organic Product - 'Natural Instinct' Body Lotion with Jojoba, Rosehip and Avocado oils. It has NO Petrochemicals, Parabens and PEG's, Silicones or Mineral Oils.
I got it from a Chemist - one that carries lots of usual Health Store products.
Good Luck finding what works for you