Red raw crown

I'm really worried about my Dad. He's been bald now for as long as I can remember (just hair round the back and sides). But for the past couple of weeks the whole top area of his head has been a vivid red colour with small red lumps on it. The rest of his head and face looks like normal. He says it isnt itchy or troubling him but it just looks so red its shocking. He has been under a lot of stress at work lately and my Grandad (his Dad) is'nt very well at all. I'm assuming that its just stress but has anyone heard of other conditions which this could be a symtom of?

I'm trying to get him to the doctors but you know what men are like (sorry for my sweeping generalisation [8D]).

Thanks very very much for your replys in advance.