Hello & welcome to Just Answer/Pearl. I am Dr. B, a licensed veterinarian and I would like to help you with your wee one today.
We do not tend to feed tomatoes (the fruit or any part of the plant)to hamsters due to its high acidity. That said, it is less likely that the tomatoes are related to this exposure due to the varied locations of the lesions.Do these patches look crusty or have scales?
Is the skin just red or ulcerated?Any visible pustules or pimples?Is Seshy itchy with them?How is she otherwise? Eating, drinking, behaving as normal?If possible, could you take a photo of this? If you can do so and post them online, I am happy to have a look (since it will let me see what you are seeing). To post them, you can either use the wee paper clip on the tool bar. Or you can post them on a 3rd party site (ie Flickr, Photobucket, etc) and paste the web address here.
Can I email it to you. I got it on film by accident. it won't attach