Thank you very much for the useful information Jerry.
The most likely cause for this salty taste is gastroesophageal reflux disease, which is usually associated with stomach or duodenal ulcers as well.
Besides reflux, other conditions can also give you the similar symptoms such as;
Poor orodental hygiene
Infections in the oral cavity
Prednisone is a steroid and it has high potential to make your reflux and ulcers go worse, and most likely it was the trigger in your case.
Right now, i will suggest you to keep yourself adequately hydrated.
Daily floss, good care of dental hygiene.
Avoid food rich in fats and spices.
Abstain from smoking.
Raise head end of the bed to about 6 inches.
Avoid tight clothings/belts around abdomen.
Do not lie flat immediately after meals (at least 3-4 hours after every meal).
Taking small frequent meals instead of three large one's will be helpful.
And can also use Prilosec (omeprazole) available over the counter.
These measures will work slowly while you monitor yourself and see how you respond to these changes.
If the symptoms persist, do not improve or get worse, see your doctor discussing the possibilities i have mentioned and have this investigated in detail so that an appropriate management plan is instituted in time.
I would have been worried too if I were at your place, but let me reassure you that this does not sound serious at all. It is a treatable condition and carries a good prognosis with appropriate management.
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