Pigmented purpuric dermatosis persistent over 20 years treated with an ozone nanobubble water oral rinse: A case study

Pigmented purpuric dermatosis is a rare, unique purpuric skin disorder, most commonly located on the lower extremities and characterized by petechiae with tiny red rashes and brown pigmented patches. The precise etiology and a reliable treatment have not been established. This case report presents a 72‐year‐old female with repeating purpuric, tiny rashes and persistent extensive brown pigmented patches with pigmented purpuric dermatosis on both lower extremities for the past 20 years. Ozone nanobubble (ONB) water is a new sterilizing agent containing dissolved nanosized ozone gas bubbles in water. The patient performed an oral rinse every night with ONB water and was successfully treated. However, vitamin C administration and Ruby laser treatment were needed to reduce residual pigmentation. This case suggests that oral bacteria may be a causative factor of pigmented purpuric dermatosis.