bubble_chart Overview

Also known as porphyria, it is a metabolic disorder caused by abnormal production and excretion of porphyrins, often with genetic factors. Based on the site of porphyrin metabolism disorder, it is classified into erythropoietic porphyria and hepatic porphyria.

bubble_chart Diagnosis

I. Medical History, Symptoms, and Signs:

Clinical manifestations include:

(1) Cutaneous symptom complex:

Mostly appears in infancy but can also occur in adults (late-onset cutaneous porphyria). After sun exposure, erythema, blisters, or even ulcers may appear on exposed skin areas. Scarring occurs after crusting, leading to deformities and pigmentation. The rash may present as eczema, urticaria, summer prurigo, or polymorphous erythema. Oral mucosa may exhibit red spots, and teeth may appear brownish-red. Concurrent ocular lesions such as conjunctivitis, keratitis, and iritis may also occur. In some patients, late-stage skin inflammation manifests as atrophy, melanosis, and symptoms resembling scleroderma or dermatomyositis. Severe cases may involve scarring and deformation of the skin on the nose, ears, or fingers, along with a characteristic purple facial appearance. Porphyria erythropoietica and late-onset cutaneous types may present with hypertrichosis. Hepatic porphyria, in addition to skin symptoms, may be accompanied by abdominal or neuropsychiatric symptoms either concurrently or during disease progression, constituting a mixed type.

(2) Abdominal symptom complex:

Characterized by acute abdominal pain accompanied by nausea and vomiting.

(3) Neuropsychiatric symptom complex:

Presents as lower limb pain and paresthesia; may also involve spinal neuropathy, leading to paraplegia or quadriplegia; or cerebral lesions, resulting in neurological, psychiatric, or autonomic symptoms such as abdominal pain and hypertension.

II. Auxiliary Examinations:

Urine often appears red (though it may be colorless) but turns red after exposure to sunlight or acidification and boiling for half an hour. Qualitative or quantitative tests for urinary porphobilinogen (PBG) are positive.

III. Differential Diagnosis:

During episodes of abdominal pain, this condition should be differentiated from acute abdomen and lead poisoning; the cutaneous type should be distinguished from pellagra; when presenting with neuropsychiatric symptoms, it should be differentiated from encephalitis, poliomyelitis, and schizophrenia.

bubble_chart Treatment Measures

Mainly for symptomatic treatment and prevention of recurrence

(1) Erythropoietic Porphyria

1. Skin lesions: Avoid sunlight exposure and trauma; apply topical 3% dihydroxyacetone and 0.13% lawsone cream. Wear protective clothing. Take oral β-carotene 60-180mg/d, or riboflavin 20-40mg/d, or quinacrine 50mg every other day.

2. Hemolytic anemia: Severe and prolonged hemolysis may warrant splenectomy, which can be beneficial and may reduce photosensitivity. Cholestyramine 4g three times daily before meals, combined with the antioxidant vitamin E, is effective in preventing the progression of liver disease.

(2) Hepatic Porphyria

1. Avoid triggers: Such as overexertion, emotional stress, hunger, infections, etc.

2. A high-carbohydrate diet is recommended, and alcohol should be avoided. During acute attacks, intravenous infusion of 10% glucose solution at 100-150ml/h, or 25% glucose solution at 40-60ml/h for 24 hours, combined with a high-carbohydrate diet, can rapidly alleviate symptoms. For those with impaired glucose tolerance, insulin therapy may be added.

3. Hormones: In a few cases where acute attacks are clearly related to the menstrual cycle, the use of androgens, estrogens, or oral contraceptives can be effective, but may lead to persistent hypertension, the mechanism of which is unknown. For patients with orthostatic hypotension, prednisone 10-20mg three times daily is highly effective.

4. Symptomatic treatment: Chlorpromazine can relieve abdominal pain and alleviate neuropsychiatric symptoms, 12.5-25mg three times daily. Prochlorperazine is more effective, 5-10mg three to four times daily. For severe abdominal pain and limb or back pain, aspirin and propoxyphene can be used.

5. Hemin: An effective measure for rescuing critically ill acute porphyria patients. The dose is 3-6mg/kg per administration, not exceeding 6mg/kg within 24 hours. Dilute with normal saline and administer intravenously at a rate not exceeding 40mg/min, completing the injection in 6-10 minutes; alternatively, it can be added to 500ml of normal saline for a single intravenous infusion. The second administration should be at least 12 hours apart, with a treatment course of 3-5 days.

6. Phlebotomy: Effective for porphyria cutanea tarda. Perform phlebotomy every 2-3 weeks, 300-500ml each time, with a total volume typically requiring 2000-4000ml. Stop when urinary porphyrin excretion significantly decreases or hemoglobin drops to 11g%. Symptoms may disappear for 6-9 months, with generation and transformation improving for 12-24 months. Individual responses vary.

7. Chloroquine: Administer intermittently at a dose of 125mg orally twice weekly. Discontinue when urinary porphyrin excretion falls below 100μg/d. The treatment course may last several months to years. Complete remission can be achieved in porphyria cutanea tarda patients. Liver function (SGPT) should be closely monitored during treatment.

8. Correct typical edema and electrolyte imbalances: For those with excessive antidiuretic hormone release, restrict fluid intake and add demeclocycline 200-400mg three times daily for 5-10 days as a treatment course. If excessive sodium loss occurs due to sweating or gastrointestinal issues with insufficient fluid intake, replenish salts and fluids. During acute attacks, hypomagnesemic spasms may occasionally occur and should be treated with magnesium salts.