Veterinary questions? Ask a Vet for Answers ASAP
I am sorry Harrys itch is coming back. Thats great you are giving him a sensitive diet, this will really help if there is a diet component to his allergic skin disease.
It is usual to expect flare ps of itchy skin especially if there is an aspect of environmental allergy causing the problem, especially now the weather is better.
The Coronoavirus situation is making it very hard to see animals, and all vets around the country are limiting the work to emergency/urgent cases. However, ALL vets are open and you should be able to access them today to discuss Harry and if appropriate more medication can be dispensed over the phone with arrangements being made to pick them up from the practice (this is what I am doing at my practice)
If for some reason you cannot get any steroids, if you are planning a visit to the supermarket soon you could get some antihistamines, I like cetirizine hydrochloride, it is a 10mg tablet and I would try giving this once a day (1 tablet for a 20kg dog and 1/2 for 5kg dog)
I am sure your vets will be able to help you though.
Good luck and take care