Acute intermittent porphyria is an inherited metabolic disorder in which lack of an enzyme called porphobilinogen deaminase results in a build-up of porphyrins in the body. It is a rare disease affecting 1-5 per million of the American population predominantly women between 18-40 years of age.
Patients with acute intermittent porphyria have no symptoms at baseline. Symptoms may be triggered by use of steroid hormones, harmful drugs, and alcohol. Low calorie and low carb food and premenstrual hormonal changes may also lead to symptoms in susceptible patients.
During the attacks, patients may develop abdominal pain, constipation, muscle weakness, numbness or tingling in the hands and feet, psychiatric disturbances such as insomnia, depression, and even schizophrenia, port-wine colored urine, and Seizures and coma.
Unfortunately, acute intermittent porphyria often goes undiagnosed. In individuals presenting with unexplained severe abdominal pain, the diagnosis is confirmed by finding elevated porphyrins in urine. Management includes avoidance of precipitating factors, treatment of the acute symptoms, and decreasing the formation of heme and precursors via administering glucose or hematin. Relatives without symptoms can be identified as carriers of the disorder by molecular genetic testing.