1 year old female pug mimi

hi i wounder if u can help. my female pug mimi has a red itchy rash on her belly in the crease off her legs and at the start of her tail,her ears are also dry and flakey and smell. i have changed her food wainwrights hypo allergenic and iv been bathing her with exmarid deep cleansing shampoo for dry scaly and itchy skin. she is ok for a week after shes been bathed but then she will start itching again, iv been told that bathing her every week will only make it worse and that the last thing i want. i feel so sorry for her i can imagin how irratating it can be 


plzzzzz can anyone help :(