Professor Luke O'Neill

None of these subtypes are in any way infectious.

There's no bacteria, there's no virus that's causing it.

You can't catch it off someone.

It's simply the skin dividing too much is the best way to describe it.

Now, what about treatments?

Well, this is the exciting bit because of all these diseases, autoimmune, and that includes things like arthritis or lupus or loads of them, you know, these autoimmune disease that we work on.

This is the one that has seen the best progress by far.

So when I began my PhD all those years ago, if you had severe psoriasis, they couldn't do much for you.

They discovered decades ago that tar, coal tar, was a way to limit some of the effects of the nastiness of the skin going red and flaking.

And so very often you'd rub in coal tar into the skin.

And that does work a little bit, right?

And then there was also vitamin D, because they did realise that if you expose psoriatic skin to sunlight, that can slow down the division of the keratinocytes.

The UV light slows their division, and that will of course slow down the whole thing, and that's why sunlight's quite good for psoriasis, but don't get sunburnt, whatever you do.

People often say, oh, in the summer, it clears up a bit.

And I noticed that because the UV light is slowing down the division of the cells in the skin.

And so UV light was used a lot.

And you'd go into hospital at that time and you'd be under a sunbed, I guess, for weeks on end.

And then the lesions would begin to clear it up a little bit.

Or on the other hand, vitamin D, because, of course, sunlight will allow vitamin D to be made in the skin.

So there were treatments there based on vitamin D. These work a bit.