Porphyria
Porphyria is a group of disorders which can lead to skin or nerve problems. This condition is caused by the buildup of porphyrins: the chemicals that help make heme, the proteins that transport oxygen from the lungs to various body parts. The symptoms vary depending on the severity and the type; the two general categories are: acute and cutaneous.
Acute porphyrias usually cause nervous system symptoms which last for days or weeks. Its symptoms include paranoia, anxiety, confusion, hallucination, nausea, vomiting, abdominal pain, chest pain, breathing difficulties, muscle weakness or pain, seizures, red or brown urine, urination problems, constipation or diarrhea, hypertension, and paralysis.
Cutaneous porphyrias cause skin symptoms which are triggered by sun exposure; the skin suddenly reddens, swells, changes color, itches, blisters, and become painful. Also, the patient may have brown or red urine and experience excessive hair growth. Porphyria is typically inherited and the triggers include sunlight exposure, hormone drugs, psychoactive drugs, fasting, alcohol intake, smoking, stress, HIV, hepatitis C, and menstrual hormones. Historically, it is believed that King George III of England suffered from Porphyria. Throughout his adulthood he would have episodes of strange behavior to the point of being considered "mad." During his last few years on the throne he was affectively removed from making important decisions in favor of his Son, later known as George IV.