Hi.. Thanks for the query.. In brief it is medicine induced Xerostomia or dry mouth.. Yes, Prednisolone as well as Enablex has a common side effect of causing dry mouth and if there is dry weather then there can also be associated dehydration.. But it is more likely to be side effect of medications.. So my suggestion is to consult your Physician and get evaluated and a thorough clinical evaluation can be done.. If it is a side effect of medication then the medication will be changed or dose will be titrated.. For now to reduce dryness you can chew sugarfree chewing gum, suck lemon drops and drink ample of water.. You can also use artificial saliva drops.. You can do cool compresses over the lips, coat them with a thick coat of petroleum jelly or bees wax containing Lip balm, avoid licking or biting the lips and follow the medication as advised by your Physician.. Hope this helps.. Regards.