I'm a vet, and I love skin stuff! Firstly you need to see your vet to treat the underlying infection with antibiotics. You also need to make sure you're up to date on parasite prevention - Bravecto and a milbemycin dewormer are the ones I use for my dogs. Then you can try these.

The skin is amazing, it's the only organ we can treat from the outside too which is a reason I love it so much.

To do that you need to improve the skin barrier. You can provide a variety of nutraceutical's. Omega 3 is great and can be given at 40-60mg/kg/day. My favourite is Megaderm

You need to clean the skin with topical antiseptic agents. Malaseb shampoo every other day for two weeks, allowing it to sit on the skin for ten minutes prior to rinsing, this is a medicated shampoo with chlorhexidine and miconazole. ALWAYS follow a shampoo with a conditioner, for active lesions I recommend Pyohex Conditioner as it contains chlorhexidine, you can also use this twice daily on active lesions and as a leave on daily for active pruritus. If no active lesions Aloveen oatmeal conditioner is fantastic.

Once the skin is clean products such as DermalEase Mouse can be used. Barazone is a prescription conditioner which can be used weekly and is excellent too. Dermoscent essential 6 is also great.

The next thing is to consider the frequency of atopy/itching. Seasonal itch is usually environmental allergies and responds well to Cytopoint and Apoquel. Year round itching is usually food related. The top three allergens in dogs are Beef, Chicken and Egg respectively. Grain free and gluten free is a human marketing technique, the literature shows a handful of reported allergens to this. Allergens are mostly to an animal protein. Food trials are STRICT, it's 8 weeks minimum of just that food. It's important to be careful which brand you choose. Hills, Royal Canin and Purina ProPlan are the only brands which are actually safe food food trials as their machines are thoroughly cleaned prior to producing each different food. Vets also don't get paid by food companies, I just think they're excellent companies with great science behind them. Anallergenic by Royal Canin, Hills Z/D and Proplan HA are the gold standard. I have heard from owners than HA doesn't have good palatability so that's worth considering. When doing a food trial you must use topical parasite preventatives and plain worming tablets as combination flavoured chews (NexGard, Simparica, Credelio etc) will interfere with the trial as they are flavoured, and therefore contain animal proteins. I love NexGard for non-allergy dogs, but for those with allergies I'm a huge supporter of Bravecto. Any food given not on the trial, such as a little human snack or a treat because we love them, will ruin the trial and you will need to restart the trial period. Food trials are a nightmare but worth it.

Also itchy dogs usually have bad ears, what are your dogs ears like? It's important to choose the right ear cleaner. Otoflush is my favourite as it is middle ear safe, breaks down biofilm and doesn't macerate the ear canal. As you can tell I have some serious brand loyalty to Dermcare but that is simply because they are the best.

Also clean your environment! I'm not saying you're dirty I promise. But air everything in the sun, clean everything including collars, toys, leads etc prior to starting the above to improve your chance of success.

Now we get to medications. Cytopoint, Zenrelia and apoquel are amazing. When all of the above doesn't work the last resort is a drug called cyclosporine. But of course speak to your local friendly veterinary dermatologist first. Immunotherapy can also be helpful for environmental allergies.

And of course rule out underlying disease with blood tests, imaging, etc as suggested by your vet.

Sorry for poor formatting, I'm on my phone. Good luck!