Thank you for getting back to me, Elisa. There are many potential causes of a skin condition like this.
The most likely is fur mites because, often, the only symptom of these pests is flaky skin that resembles dandruff in humans. As the infestation progresses, the rabbit may start losing hair excessively, resulting in bald spots. Fur mites cannot be seen with the naked eye, and many times they don't even show up when a vet does a skin scraping. They are treated with selamectin (sold as Revolution or Stronghold). It is applied to the skin between the shoulder blades.
Another possibility is sarcoptic mange. This is also caused by a parasite. It is treated with injections of ivermectin.
From your description, these two conditions seem most likely. However, a fungal or bacterial infection is also possible. You'll need to have a vet examine Olivia for a certain diagnosis and to get proper treatment. The drugs you'll need are only available by prescription. Sometimes rabbit owners try to save some money by treating with remedies they can buy in pet stores. Most of them don't work, and some of them are downright dangerous for rabbits. You can read more about skin conditions and treatment at this site:
This is not an emergency, but you'll need to make an appointment with a vet soon. This link will take you to a directory of rabbit vets:
If you can't find one near you, and you have to go to a vet who isn't familiar with rabbits, it might be a good idea to print out the page at the first link I gave you to take along to your appointment. Do be sure that no one gives you Frontline to use on a rabbit - it can be fatal.
I also recommend that you eliminate the pine shavings. Pine gives off volatile oils, and Olivia id breathing them, even though she isn't sleeping in the bedding. The oils can lead to respiratory and liver/kidney problems. If you want to use shavings, aspen is better. Paper-based beddings, such as CareFresh, are best.
If you have any more questions about this, just let me know by clicking on REPLY. I hope your rabbit's skin problem will be quickly diagnosed and remedied.