Red Patches Around Mouth and Nose

[pangaea11]

Hi.
I am a little worried about my 18 month old after his breakfast this morning red patches appeared around his mouth and Nose. It looked like he had been rubbing the area and as he is teething I put it down to this, but it still hasn't cleared. I thought it could be allergy related but he had nothing different to eat. Any help or ideas on what could have caused it? Thanks