What is causing this pressure blister?
NOT all blistering on the legs is due to conventional disease. Sometimes physical factors alone are responsible.
The phenomenon is common in elderly patients with severely sun-damaged skin, which can be thin like paper. The underlying dermis has lost all supporting collagen and elastic tissue.
With mild cardiac or renal failure the patient starts to accumulate fluid in the lower legs and feet. Fluid leaks from the capillaries and accumulates in the dermis. This leads to separation of the epidermis from the dermis at the dermo-epidermal junction.