foam problem

I just brewed a batch of ale from my own recipe in which I added 12oz of
Maltodextrin in my boil. After I was finished with the batch it was left to ferment. I got up in the morning and had no activity in my airlock when I came home from work I found a foam irruption from the airlock with the strong hiss of co2 escaping from the foam. after reading some other threads I believe it is the maltodextrin in the brew if this is true is there anyway to stop the foam without changing the recipe or adding any other ingredients.

I'd just want to rule out that this is not just vigorous fermentation......What are you fermenting in? What yeast are you using? I have krausen (Which can look a little different with different yeast strains- and at times it's foamy) go up and out of the airlock Many times. When I culture yeast from Brewery Omegang's Wit- this is almost guaranteed. And then you would just use a blow-off tube....
Other than that- I think more info is needed.....

I am fermenting in a 6.5 gallon ale pail and using 1.75oz of german ale yeast the temp is staying around 70 degrees

If I'm not mistaken, I think German ale yeast is best fermented in the low 60s. You may have a "hot" fermentation there.

You may need to pull off the airlock and install a blow-off tube, and keep it in the bathtub/shower in case it blows.

I'd try to keep it under 68 degrees, if you can. That will help make a better tasting beer, as well as keep fermentation a bit cooler. Fermentation can actually cause the temperature inside the fermenter to rise as much as 8-10 degrees, so if the room is 70 degrees, it's probably much hotter inside. I use a stick-on thermometer (like for aquariums) to help gauge the temperature of the fermentation.

I'll look for some links on blow off tubes, so you can rig one ASAP.

Edit- maltodextrine doesn't have a thing to do with the fermentation. It's not fermentable. It provides body and mouthfeel.