I can't help regarding your husband's condition. But, if finding SSKI in the UK is impossible, you could consider making your own. I found the potassium iodide crystals available at least on ebay.co.uk, and Trapper has left us with his formula. Best wishes!
the recipe is easy. put one kilogram of KI in a one liter bottle. add enough water to cover it and shake it up. it will get really cold. add more water and shake that up. keep adding water until you just about reach the fill mark. the KI should be mostly dissolved or already dissolved. it should all dissolve and fill the bottle just barely. then you know you have one gram of KI in each ml of solution.