"Sounds like that could be what they call Southwest Injury--where bark warms up on sunny winter days then becomes damaged when it freezes after sundown. Score the bark with a sharp knife, removing any pieces that could harbor insects or moisture. Don't remove any more of the bark than you absolutely have to. If the wound doesn't go around the whole tree, then it may recover. Then next fall, wrap the bark in protective sleeve, burlap, or tree wrap for the winter, removing in spring.
Luke Miller, editor
Garden Ideas & Outdoor Living magazine"