Porphyrin Tests
Porphyrin tests measure levels of porphyrins in blood, urine, or stool to help diagnose or monitor porphyrias, a group of rare, often inherited disorders.
Overview
Porphyrins are used by the body to make heme, a component of hemoglobin that carries oxygen in red blood cells. Porphyrias occur when the body lacks the proteins necessary to convert porphyrins into heme, causing a buildup that leads to illness.
Types of Porphyria
- Acute porphyrias: Sudden onset, lasting days or weeks; primarily affect the nervous system.
- Cutaneous porphyrias: Long-lasting; affect the skin, causing blisters or pain upon sunlight exposure.
Symptoms
Acute Porphyria
- Abdominal, back, or limb pain
- Constipation
- Nausea and vomiting
- Mental changes (anxiety, confusion, seizures)
- Urinary issues or red/brown urine
- Nerve problems (muscle weakness, paralysis, breathing difficulties)
Cutaneous Porphyria
- Blisters, fragile skin, or scarring
- Infections in wounds
- Sunlight-induced pain, burning, stinging, tingling, redness, or swelling
Causes
Most porphyrias are inherited. However, acquired porphyria can develop after age 30 due to factors such as:
- Hemochromatosis (excess iron)
- Alcohol use disorder (AUD)
- Smoking
- Viral infections (Hepatitis C, HIV)
- Estrogen-containing medications
- Lead overexposure
Testing Procedures
- Blood Test: A sample is taken from a vein in the arm.
- 24-Hour Urine Sample: All urine is collected over 24 hours to account for variations in substance levels throughout the day.
- Random Urine Test: A single sample provided at any time.
- Stool Test: A sample is collected in a special container.
Note: For stool tests, you may be instructed to avoid meat and aspirin-containing medicines for three days prior to the test.