Blood vs Skin Allergy Testing for Dogs - Reliability

I am looking into allergy testing for my dog with chronic skin problems. I have a cheap wellness clinic I go to for routine things and discussed her issues with them last time I was in for shots. They recommended allergy blood test in their clinic and put her on apoquel in the meantime. Several clinics in my area offer a blood serum test, while my usual preferred vet (not the cheap place I go for shots but who I trust for more complex things) does not do blood tests and referred me to an animal dermatologist for skin (and maybe also blood) testing. I am unclear if they do not offer blood tests because of reliability issues so have been trying to research it. I have read that intradermal testing is the gold standard but also that injections based on the blood test results have a (possibly equally) high efficacy rate. But to me it is a red flag that all the places I called that do blood testing offer both environmental and food allergy panels, even though only elimination diet has been found to be suitable for detecting food allergies. Bottom line, blood test is a fraction of the cost of seeing a dermatology specialist for testing, and does not require driving over an hour to a specialist. But neither is cheap and both involve long term treatment to see results. Should I go to the specialist or give the blood test a try?