Hi.. Thanks for the query.. Steroids in the form of either inhaler or oral are commonly seen to cause a fungal infection on the tongue known as Oral Thrush and it is the cause of white coating in your case.. Tingly feeling or irritation of tongue can be due to inflammation of the tongue due to infection.. You should consult an Oral Physician and get evaluated. Mostly a clinical examination is sufficient for diagnosis or else microscopy of scrapings from tongue can be done to confirm.. You need to take antifungal medication like Fluconazole along with Nystatin mouthwash gargles and take plenty of probiotics like Yogurt.. Suck Clotrimazole lozenge and keep the tongue clean. Avoid using antiseptic mouthwash.. Hope this helps.. Regards..