Porphyria cutanea tarda (PCT) is a rare skin disease. There are two types of PCT: acquired PCT, which represents 75% of cases, and familial PCT, which makes up the other 25%. Those with familial PCT usually show symptoms earlier in life than those with acquired PCT. Symptoms of PCT include extreme light sensitivity and blistering skin lesions upon even slight exposure to sunlight. Hyper- or hypopigmented (less or more pigmented) skin and increased hair growth may also be symptoms of PCT.
Familial PCT is caused by low levels of URO-D, a protein involved in parts of red blood cells. URO-D deficiency is caused by a mutation in the URO-D gene -- a deficiency in URO-D causes porphyrins (a subunit of red blood cells) to build up in the liver, which may lead to increased risk of liver problems or cancer. Not everyone with the URO-D mutation will develop symptoms of familial PCT.
Diagnosis of PCT involves testing blood or urine samples for porphyrin levels. If they are unusually high, familial PCT is confirmed by identifying low levels of URO-D in blood cells. Genetic counseling services may be available to families with familial PCT in order to assess who might have or pass on the mutated (changed) URO-D gene.
PCT is the most treatable form of porphyria diseases. Treatment for PCT includes eliminating substances that increase risk for PCT onset, like alcohol consumption or use of drugs that include estrogen, like oral contraceptives. Regular procedures to remove blood to reduce blood iron/porphyrin levels may also be necessary. This practice usually results in complete remission; however, in some cases, certain drugs may be given to reduce blood-iron levels as well.
If you or a family member has been diagnosed with familial PCT, speak with your doctor about the most current treatment options. Support groups may also be available for further resources and information.
Description Last Updated: Aug 22, 2018