Porphyria, also known as hematoporphyria, 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

1. Medical history, symptoms, and signs:

Clinical manifestations include:

(1) Cutaneous symptom complex:

Mostly appears in infancy but can also occur in adults (porphyria cutanea tarda). After light exposure, erythema, blisters, or even ulcerations appear on exposed skin areas. Scarring occurs after crusting, leading to deformities and pigmentation. The rash may present as eczema, urticaria, prurigo aestivalis, or erythema multiforme. Oral mucosa may show red spots, and teeth may appear brownish-red. Concurrent eye damage such as conjunctivitis, keratitis, or iritis may occur. In some patients, late-stage skin allergic inflammation results in atrophy, melanosis, and phenomena resembling scleroderma or dermatomyositis. Severe cases may involve scarring and deformation of the skin on the nose, ears, or fingers. A characteristic purple facial appearance may be present. Porphyria erythropoietica and porphyria cutanea tarda 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:

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

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

bubble_chart Treatment Measures

Mainly 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. 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 indicate splenectomy, which can be beneficial and reduce photosensitivity. Cholestyramine 4g three times daily before meals, combined with the antioxidant vitamin E, is effective in preventing liver disease progression.

1. Avoid triggers: Such as overexertion, emotional stress, hunger, infections, etc.
2. A high-carbohydrate diet and alcohol abstinence are recommended. 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, androgens, estrogens, or oral contraceptives can be highly effective, but may lead to persistent hypertension of unknown mechanism. For patients with orthostatic hypotension, prednisone 10-20mg three times daily is beneficial.
4. Symptomatic treatment: Chlorpromazine can relieve abdominal pain and neuropsychiatric symptoms, 12.5-25mg three times daily. Prochlorperazine is more effective, 5-10mg three to four times daily. Severe abdominal pain and limb or back pain can be treated with aspirin and propoxyphene.
5. Hematin: A critical treatment for severe acute porphyria. The dose is 3-6mg/kg per administration, not exceeding 6mg/kg within 24 hours. Dilute in 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 infusion. The second dose should be given at least 12 hours apart, with a treatment course of 3-5 days.
6. Phlebotomy: Effective for porphyria cutanea tarda. Perform every 2-3 weeks, 300-500ml per session, with a total volume typically requiring 2000-4000ml. Discontinue when urinary porphyrin excretion significantly decreases or hemoglobin drops to 11g%. Symptoms may disappear for 6-9 months, with improvement in generation and transformation lasting 12-24 months. Individual responses vary.
7. Chloroquine: Administer intermittently at 125mg orally twice weekly. Discontinue when urinary porphyrin excretion falls below 100μg/d. Treatment may last several months to years. Complete remission can be achieved in porphyria cutanea tarda. Monitor liver function (SGPT) closely 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. For those losing excessive sodium through sweating or gastrointestinal losses with insufficient fluid intake, replenish salts and fluids. Acute attacks may occasionally cause hypomagnesemic spasms, requiring magnesium supplementation.

bubble_chart Differentiation

When abdominal pain occurs, it should be differentiated from acute abdomen and lead poisoning; the cutaneous type should be distinguished from pellagra; when presenting with psychiatric and neurological symptoms, it should be differentiated from encephalitis, poliomyelitis, and schizophrenia.