I think that if you have a skin rash to one gliptin, then you will probably get the same with all members of the class.
I guess you have tried metformin and modified release metformin?
Something from the empagliflozin class would be my next suggestion, particularly empagliflozin, since it helps to lose weight and avoid heart attacks and strokes.
Then it gets fiddly.
Sulphonylureas increase weight and cause hypos with no effect on vascular disease.
Pioglitazone decreases risk of dementia and heart attacks etc without hypos, but puts on the weight.
Acarbose has awful flatulence and very few folk can take it.
Then there are the prandial glucose regulators, nateglanide and repaglinide, which have low but not zero risk of hypos; one takes them with each meal, so are useful for folk with variable eating patterns.
Then it is injections eg GLP-1, when one would want something ending -glutide which prevents strokes and heart attacks rather than one ending -enetide, which does not.
best wishes