Professor Luke O'Neill

There's plaque psoriasis.

That's the most common one, really, where you get these big patches.

They're called plaques that spread out from the lesion.

That's plaque psoriasis.

Gut eight, that's spots, little pimples, I suppose.

And then you have pustular, and they are big spots full of pus.

Pus is an interesting substance, actually, in itself.

You'll all be familiar with pus that you see in a spot for instance.

What pus is actually is dead neutrophils.

Now neutrophils are a very important cell in the immune system and they fight infection and when they die they form pus.

So whenever you see a bacterial infection you often get pus because the neutrophils have fought the good fight.

They've killed the bacteria and then they form pus.

And lo and behold, it's subtype of psoriasis.

You see loads of neutrophils.

You might call it neutrophilic psoriasis.

And that ends up in pus in these lesions.

And as I'll come back to, there's a slight difference with pustular psoriasis versus plaque psoriasis.

So there's these different types that have been spotted.

They were mainly described, oh, decades ago, I suppose, because you could see the skin was slightly different between people with these different types of psoriasis.

Now, there's one other type as well to mention, and it's called psoriatic arthritis.