We were leaving Sainsburys yesterday when someone stopped me and started talking about Psoriasis. It wasn't a completely random event because I have suffered from it on my scalp for a couple of years and it's visible at the top of my forehead. He had suffered from it for several years and wanted to pass on some advice. He told me to avoid anything with red berries in it, and that included red wine. He also suggested the original Head & Shoulders 'all-in-one' shampoo and conditioner rather than the coal tar shampoos which are usually recommended for the condition.

We chatted for a few minutes, then thanked him and left the shop. It shouldn't be too difficult to follow his advice. It certainly won't cost much when the only thing we need to buy is a standard off the shelf shampoo. Some of his other suggestions, such as avoid processed food and additives, we do anyway.

We were back in the supermarket tonight. We realised that the definition of red berries was a bit ambiguous. It might mean:

• Red Grapes (and by extension, raisins)
• Strawberries and raspberries
• darker berries such as blackcurrants
• possibly even tomatoes

We had to buy some more squash because the ever-so-tasty Vimto and the blackcurrant drink in the house might be unsuitable. We had to buy apricot jam because the strawberry jam in the fridge might count. I had to put the malt loaf back on the shelf because of the raisins. I won't be able to drink the purple grape juice in the fridge.

I'll give it a few months and see if it improves.