Porphyrias

Porphyrias are a group of rare blood disorders caused by a mixture of inherited and environmental factors. They are due to the accumulation in the body of a substance called porphyrin, which is normally used as a component to make blood cells. Symptoms include blisters, itching, and swelling of the skin when it is exposed to sunlight. Other factors such as the use of certain medicines, smoking, alcohol, infections and stress can also trigger symptoms. Each type of porphyrias has a different treatment

Source: GreenFacts