All of the hepatic porphyrias--except porphyria cutanea tarda--follow a pattern of acute attacks separated by periods during which no symptoms are present.

Hepatic porphyrias.

The underlying cause of all porphyrias is a defective enzyme important to the heme biosynthesis pathway. Porphyrias are inheritable conditions.

The repetition in the poem Porphyrias Lover is "that moment she was mine, mine".

The erythropoietic porphyrias and porphyria cutanea tarda are considered to be chronic conditions.