Causes and risk factors
Prophyria occurs when there is problem with conversion of porphyrin into heme which leads to its accumulation. In most cases porphyria is inherited but it can also be an acquired defect. Inherited form occurs due to inheritance of defective genes. Genes associated with the disease are ALAD, ALAS2, CPOX, HMBS, PPOX, UROD, UROS, FECH. Common triggering factors for porphyria are drugs like barbiturates, tranquilizers, birth control pills, sedatives. Risk factors include dieting or fasting, smoking, alcohol use. Infections or other physical stress, mental stress can lead to the disease. Sun exposure, excess iron in your body facilitates porphyria.
Clinical presentation
Based upon symptoms, porphyria is classified into two types as acute porphyria and cutaneous porphyria. Acute porphyria primarily affects nervous system causing acute neuropathy, muscle weakness, cramps, tingling, loss of sensation, seizures. Abdominal pain, vomiting, constipation, diarrhoea is observed due to imbalance in sodium levels. Patient complains of hallucinations, depression, anxiety, paranoia, insomnia. Cutaneous porphyria primarily affects skin causing itching, increased hair growth on forehead, painful skin redness [erythema], swelling [oedema], darkening and thickening of the skin, blisters, necrosis of the gums and skin. Red coloured urine is observed.
Investigation
Medical history by the patient and Clinical examination by the doctor helps in diagnosis. Blood, urine and stool samples. Blood and stool are examined for levels of prophyrin. Urine is examined for elevated levels of porphobilinogen. Skin biopsy is recommended to rule out other diseases.
Treatment
Discontinuation of the triggering medications is required. Intravenous dextrose infusion to help in recovery. Injections to reduce the load of heme production on body may be required. Medicines to control pain, nausea and vomiting are useful. Intravenous fluid to manage dehydration is needed. Cutaneous porphyria treatment consists of regular blood removal [phlebotomy] to reduce the amount of iron in the liver. Medications like low doses of the antimalarial drug to absorb prophyrin, daily doses of beta carotene to increase skin tolerance will also help in managing porphyria.
Facts and figures
Porphyria affects 1 in 500 to 50,000 people worldwide.
