Porphyria Cutanea Tarda

**Semantic type:** Disease or Syndrome

**Definition:** A cutaneous form of the genetic photosensitive disease, porphyria, that is characterized by onset in adult life and the presence of scarring bullae, hyperpigmentation, facial hypertrichosis, and sometimes sclerodermatous thickenings and alopecia. Uroporphyrins are found in the urine due to a deficiency of uroporphyrinogen decarboxylase, an enzyme required for the synthesis of heme.