I would suggest that you call your veterinarian's office. You don't have to actually take your dog in for an appointment unless that is what is advised over the phone.
Not only will the vet or vet's assistant give you sound advice on what to do, you shouldn't be charged for the consultation.
Also, check the anti-itch cream to see if it has a warning about it being ingested or not. This may be indicative of whether or not it will be harmful for your dog.
But the most important thing is to get a professional opinion (i.e. vet/vet assistant).My doberman just ate an entire tube of Aveeno anti-itch cream, harmless?
Judging from some of these cautions on a page about people using hydrocortisone, I think you should consult a vet to make sure.
';If the medication is ingested, or if a large amount is used over a large area and side effects are being experienced, call an emergency room or a poison control center near you.';
There is a list of side effects on that page, too.
Edit: I have a tube of the same stuff, I checked the label and it also says to contact poison control if swallowed.My doberman just ate an entire tube of Aveeno anti-itch cream, harmless?
Keep an eye on your dog if it starts acting sick take it to the vet.