Have them get some wipes for sensitive skin and keep the nose and rash area clean he may need some cream for the rash, what do his parents say about it ?
The runny nose maybe an allergy, I would have him checked out by the doctor the rash may be coming from the runny nose having an effect on his skin and making it sore ..
Could be staph, or thrush, or yeast, or just irritation. What does his mother say about his constant runny nose?