My dog Willow, a chocolate lab, has allergies this time of year and her ears get really itchy. If I don't keep up on top of it, her ears can get quite inflamed and swollen, looking like raw meat with a dark brown to black discharge. The last time it happened, it was a yeast and bacterial infection. It required an ear medication that had antibiotic, antifungal and anti-inflammatory meds in it. If it is that bad...then I second Luella's advice to get to the vet.
If I keep on top of Willow's ears by cleaning them frequently with the ear wash the vet gave me and giving her a claritin for the itchiness we're ok. But if I let it go even for a week, her ears are a mess. So far, knock on wood, we haven't had to go to the vet at all this year.