A group of inherited disorders involving abnormalities in the production of heme pigments (the base material responsible forhemoglobin (red blood cell pigment), myoglobin (reddish muscle cell pigment) and another group of materials calledcytochromes. Porphyrias are characterized by three major findings: photodermatitis (light sensitivity causing rashes) ,neuropsychiatric complaints and visceral complaints abdominal pain, cramping, and so on.

The porphyrias may be inherited as either autosomal dominant or autosomal recessive traits depending on which type ofporphyria is involved. Some types of porphyria have their onset in early childhood, some at puberty, and others duringadulthood.A classical attack of acute porphyria generally begins with colicky abdominal pain (severe) followed by vomiting andconstipation. Personality changes may develop during an acute attack as well as peripheral paresthesia (numbness and tingling) ,weakness, paralysis, sensory changes and muscle pain. Acute attacks can be lifethreatening, producing severe electrolyteimbalances, low blood pressure and shock.Urine may become red following an attack. In congenital erythropoietic porphyria, the urine is constantly red.Exposure to sunlight can cause reddening, pain, sensations of heat, blistering and edema in the skin. These lesions heal slowly,often with scarring or pigment changes and can be disfiguring.

Genetic counseling may be of benefit to prospective parents with a family history of any type of porphyria.