Hello Ana!
It sounds like scab, which is relative to rain or the periods of moisture the tree is exposed to. Proper pruning will help, and a few other things as well. First things first, you need to get the tree healthy. Start by giving it proper ballenced nutrition, and creating healthy soil dynamics. Have a qualified Arborist, who disinfects their tools, prune off anything dead, damaged or diseased this Spring. Fruit or leaf scab doesn't qualify as diseased, so don't worry about that now. Once the 3 Ds are done this spring, then you can do a 15% total thinning delegated to reduce height, and cantilever weight reduction on the large outter limbs. Thats about 7% thin to reduce height, and 7% thin on cantilever weight reduction, on the big heavy limbs. That's all the pruning I would recomend this year. Fruit trees need anual pruning, but for a pear, I would only recomend 15 to 20% per year in restoration and maintenance. Next dormant season, then do up to 20%, delegating each percentage to the most needed aspects of restoration or pruning. The main things you need to worry about with prunings, and why an experianced arborist is so important. Is finding an Arborist who will make the best cut selection, and find symbiotic solutions in working with the trees genetics as they relate to environmental expression. And in doing so, training the tree to recover from damage, thin for height reduction, thin for cantilever weight reduction, thin for light and air circulation, thin to maintain ballence, keep the tree beautiful, and of
course water sprout removal. If they don't disinfect tools, dont use them.
For nutrition use Sea-90 minerals and Epsom salt, both at half doses quarterly. Also use properly aerated/brewed, worm casting/compost tea. For applying the tea, spray the entire tree, its leaves, and the soil out past the drip line applied quarterly. The tea properly made and applyed, acts as a probiotic, that will fight against the pathogens which cause scab. Also mulch the ground with some well made ballenced
compost, mixing in your ammendments, and get some healthy ballenced soil going. If you want to run a soil test, I would recomend doing it before doing your yearly amendments of mulch, so you can adjust your mix accordingly. After the first year of tea spraying, and prunning, things should improve drastically. The scab is more of a cosmetic issue, that tends to be problematic in wet springs, or when fruit trees go unpruned to a degree that it lets moisure linger. Im guessing your situation was a combination of both, but don't let the scab bother you. Scab blows around in the wind everywhere, and if the tree has a virus, only improperly disinfected tools would spread it. Once the tree is receiving proper nutrition from healthy soil, its immune system should keep it healthy.
Make sure you use a qualified arborist, and not some wanna be orchardist, who thinks they can cut to much. You need someone who will attend to details, and make wise decisions when choosing cuts. Less is more, and it will take at least three years of annual pruning to restore your tree properly.
Any questions?