Pustular psoriasis on the foot of a 83 year old male patient. This form of psoriasis that causes pus-filled blisters on patches of scaly, flaky skin (plaques). The blisters can burst open causing he skin feel tender and sore. It typically affects the hands and feet, but can appear anywhere on the body. The cause of this condition is not fully understood, but it is thought to be due to an overactive immune system. There is no cure, however, topical treatments and anti-inflammatories can be used to alleviate symptoms. For another image of this patient see SPL code C060/2245.