nostril crust

[Siders]

I am a little concerned, could any one shed any light as to what this could be? Around the left nostril on my 7 month old nosy be appears to be a small black ring of crust/bogey! I think, I know if they have too much supplementation they can snort out the excess, the right nostril is fine the left one only has it. He can breath properly and doesn't appear to have any poblems breathing, it doesn't block his nostril it just looks like a crusted ring on the outer edge. Does any one know what this could be?

 

[beeze]

Can you post a picture?

 

[Siders]

I am at work at the moment will try before his lights go out when I get home.