Due to the country's regulations, you need to consult a local veterinarian in order to get a prescription for Rilexine. However, you can purchase it on a page called farmaciaveterinaria.es. You must know your dog's weight and administer it at your own risk.
I would recommend you to give her baths with a chlorhexidine-based shampoo (ado - chlorhexidine) for veterinary use, 1 bath 2 times a week for 2 weeks and then 1 bath weekly for 4 more weeks.
Also, you can administer Dermovital (veterinary use) 3 capsules orally every 24 hours for 8 weeks. This contains omegas, vitamin E, selenium, etc. that help regenerate skin and hair in allergic processes or infections.
If a food allergy is suspected, your dog might need to go under an elimination diet with hypoallergenic food such as eukanuba dermatosis FP, z / d allergy and skin care, royal canin anallergenic. It should be mixed with her regular food for 5 days to avoid diarrhea. Continue with this plan for at least 12 weeks. While she's been given such food, she must not consume any other food, snack or canned food whatsoever. If the signs are controlled, it would be advised to continue with this diet for life.