What Causes Pale Face With Red Blotches After Running?

My son is 21. He is lactose intolerant and had always had intestinal 'issues'. He is a college student and seems to get sick every semester during mid terms and finals (cold/cough/congestion) which I attribute to lack of sleep and lots of stress.

Two weeks ago, he ran a 5k and his face was white with red blothes after he was done. I recalled how that was always how it looked in jr high and HS while playing basketball.

Is this a cause for concern