Porphyria.

Porphyria is a group of diseases caused by a deficiency of one of the enzymes involved in the production of heme - a component of haemoglobin and affects the skin and nervous system. This deficiency can cause a variety of symptoms, including muscle weakness, abdominal pain, nausea, vomiting and confusion. Other symptoms include increasing sensitivity to the sun, itching and swelling.

It is said that toxins resulting from the...