Gern, here is a direct link to info on how medications affect the voice, including corticosteroids. If you go armed with print outs of some of what I linked to, your doctor will know you are serious about being fully informed of the treatment and risks he/she has in mind.

Effects Of Medications On Singers

Here is the page on Taking Herbal Medicines: What Singers Should Know
Be aware that herbs are not necessarily "safer". Chemicals found in botanicals can have side effects and risks, too. For example, long term use of chamomile can lead to rag weed allergy.

Many people have naturally open, relaxed singing voices, and that beautiful natural sound is what I like to hear in folk music, not the obviously 'trained' sound or 'styled' voice. I love to listen to Frank Harte and many others who give the music its authentic richness in the way it is sung. Again, my breath support comments are to help you avoid abusing your voice and causing damage to it.

Alice