A fracture blister is a bulla that develops in the vicinity of a bone fracture. It occurs in 2.9% of all hospitalized acute fracture cases and develops 6-72 hours after the fracture. Increased interstitial pressure in the soft tissues from the injury leads to edema that may contribute to subepidermal clefting. Fluid transfer into the cleft leads to bulla, and sometimes vesicle, formation. The vesicles and bullae may be filled with serous fluid, blood, or serosanguinous fluid.

Anatomic sites with thinner skin and limited muscle and adipose coverage, including feet, ankles, elbows, knees, wrists, and the distal tibia, are particularly at risk for fracture blisters, although any body site may be affected. The most common types of injuries associated with fracture blisters include pilon fractures, calcaneus fractures, and ankle fractures, followed by distal humerus fractures. Risk factors include high-energy fractures (eg, falls of an average of 18 feet, motor vehicle accidents, pedestrian versus motor vehicle accidents), hypertension, smoking, alcohol abuse, peripheral vascular disease, connective tissue disease, lymphatic obstruction, and diabetes.

Fracture blisters may increase the risk for postoperative complications such as infections. Patients of any age group or sex may be affected. Acute compartment syndrome may be present.