Assistance paying for Air Purifier?

My daughter has severe eczema and her allergist has concluded that dust is the cause. The allergist prescribed medication and supplied a list of all the changes that will be required to get dust to a minimum and thus prevent my daughter from developing a more serious condition. Purchasing a quality HEPA air purifier is top priority but for her father and I it’s the cost that has prevented us from taking that step. She is covered by Medicaid. Does anyone know if there is a program that can assist us? Thank you for any advice.