I have issued a Schengen visa from the Italian embassy for tourism. In the visa application, I declared that I will enter Germany first, and then I will stay the longest in Italy.
I'm in Germany now, but I won't be able to visit Italy. My travel plans have changed and I will now be leaving the Schengen states from Germany.
Will this cause me any type of trouble?
As a tourist, you probably have a visa for all Schengen states. Check your visa, it should say "Stati Schengen" or something like that. That means you can travel through all Schengen states as long as that travel is consistent with your statements and your itinerary in the visa application.
You wrote that you applied to visit Germany and Italy. If you simply cut your visit short and travel home partway through your itinerary, there will be no problem. If you travel to another Schengen state to catch a flight from there, there will be no problem, either. If you stay much longer in Germany than planned, there may be questions.
