There are a number of medications and supplements that can be helpful in reducing skin inflammation.
In mild cases, anti-histamine medication such as hydroxyzine or cetirizine is an excellent and safe choice for controlling allergies, and can be used for the long term without side-effect or danger. In some cases, stronger cortisone-based tablets such as Prednil are required to control allergic flare-ups. These tablets are also very safe if used correctly, but should only be maintained for short periods as needed.
Of course before starting any medication you should discuss your pet’s condition with your veterinarian, not all medications are suitable for all pets and conditions and your vet will help you to determine the best treatment.