Hello I Am Inquiring About Chapped Lips. My Husband's Lips

Hello I am inquiring about chapped lips. My husband's lips started chapping a year ago six months later my lips started chapping three months later my 16-year-old's lips started clapping study around the same time my twenty six-year-old's lips started chappingand now six months after that my son who is nine years old his lips started chappingand we have been to a ton of dermatologists and Everyone says that you cannot catch chapped lips. We don't know what to do we are all putting Vaseline and all kinds of balms and trying natural things to stop the chapping but it doesn't go away and now the whole family is affected any idea what this might be?