Friction blisters: A new paradigm to explain causation

Friction blisters on the feet are a common occurrence when individuals engage in active pursuits such as running, hiking and military training. The high prevalence of blisters in active individuals underscores the fact that this pathology is not fully understood in terms of its pathomechanics. The traditional blister causation paradigm revolves around heat, moisture and friction. In reality, foot friction blisters are caused by repetitive shear deformation. The three fundamental elements of blister-inducing shear deformation include: 1) motion of bone; 2) high friction force; and 3) repetition of the resulting shear events. Rubbing at the skin surface is not a mechanism for friction blister formation. To that end, prevention of the friction blister continues to be an elusive quest for both the patient as well as the treating clinician. This article aims to highlight the limitations of the long-held blister causation paradigm and offer a new explanation.