Prolidase deficiency is a very rare autosomal recessive inherited disorder of metabolism caused by mutations in the PEPD gene. Also referred to as hyperimidodipeptiduria, it is characterized by early skin lesions, chronic skin ulcers, and excessive peptides in urine (imidodipeptiduria). Skeletal and facial abnormalities (including hypertelorism, a flat nasal bridge, micrognathia, and a high brow of the forehead), intellectual disability, and recurring infections (skin, ear, and respiratory) may also be present due to abnormalities of collagen formation in connective tissue. Hepatomegaly and/or splenomegaly may also be apparent on exam.

Onset is typically during infancy, or the condition may have delayed onset.

Treatment is focused on controlling skin ulcers and avoiding complications from unhealed ulcers such as infections or amputations.