Mixed porphyria

Introduction to mixed porphyria Mixed porphyria (variegatedporphyria), also known as variegated porphyria, is an autosomal dominant inheritance that has both abdominal and neurological symptoms and chronic photosensitive skin symptoms. A few people only have skin photosensitivity symptoms often misdiagnosed as delayed skin photosensitive porphyria. The disease is autosomal dominant, more common in the Dutch family of South Africa, found in 13 families. Both men and women can develop the disease, and the age of onset is usually from puberty to 30 years old. basic knowledge Sickness ratio: 0.0001%-0.001% Susceptible people: no specific population Mode of infection: non-infectious Complications: abdominal pain, herpes

Cause of mixed porphyria

Cause:

Autosomal dominant genetic disease, genetic chromosomal defects, caused by defects in protoporphyrin oxidase, due to defects in protoporphyrin oxidase, increased production and excretion of ALA and bilirubin, in the onset and remission period A large amount of coproporphyrin and protoporphyrin are discharged, and the occurrence of skin damage is related to exposure to sunlight.

Pathogenesis:

The disease is mainly caused by the defect of hereditary protoporphyrinogen oxidase. The enzyme gene is located on chromosome 1q23. There are many types of point mutations in the patient's genes, resulting in the patient's enzyme activity being only normal 50%, resulting in the accumulation of protoporphyrinogen in the body. At the same time, protoporphyrin is a competitive inhibitor of coproporphyrinogen oxidase, which in turn forms coproporphyrinogen accumulation in the body. Some patients have found defects in heme synthase deficiency or uroporphyrinogen decarboxylase, indicating that there may be Two different mutant genes cause genetic defects in the disease. In addition, due to the blocked heme synthesis, the feedback inhibition of ALA synthase is reduced. The above comprehensive causes the porphyrin precursor and porphyrin to increase, resulting in corresponding nerve and skin photosensitivity. symptom.

Mixed porphyria prevention

1. Avoid inducement should not take a variety of drugs that cause symptomatic porphyrinuria. Avoid excessive fatigue, mental stimulation and hunger, alcohol, infection and other incentives to reduce the onset of the disease.

2. Dietary sugars have the effect of inhibiting ALA synthase, so high glucose intake is quite effective in preventing and treating the onset of most cases. In the acute attack, 10% ~ 25% glucose or fructose at a rate of 10 ~ 15g / h, intravenous infusion for 24h, with a high-glucose diet can quickly relieve symptoms.

If you can diagnose early, pay attention to prevention and treatment, the prognosis is not necessarily bad. Long-term repeated authors, poor prognosis. Patients with neurological symptoms have a poor prognosis. Patients often die of ascending paralysis or respiratory paralysis in an acute episode, with a mortality rate of 15% to 20%. Most of the deaths were among the young people before the age of 30. Early detection of patients, pay attention to avoid various predisposing factors, pay attention to supportive care and care during the attack, especially for respiratory paralysis patients with respiratory monitoring, rational use of hemoglobin rescue treatment, the mortality rate can be greatly reduced. With the increase of age, the disease tends to reduce, and the prognosis is better.

Mixed porphyria complications Complications, abdominal pain, herpes

Abdominal pain, herpes. Often secondary infection, healing is very slow. Self-pigmentation and dimple scars after healing can lead to death in an acute episode.

Mixed porphyria symptoms Common symptoms Abdominal pain Skin mild erosive skin blisters or bullous damage

The disease rarely occurs before puberty, clinical symptoms often appear after puberty to 30 years old, the severity of symptoms is very inconsistent, both men and women can be ill, female patients often have a history of acute attacks, may be related to hormone changes in the body or regular medication, Male patients with skin lesions are often more common, may be more exposed to sunlight, clinical symptoms and acute intermittent porphyria, the main manifestations of skin manifested as photosensitive dermatitis, skin fragility increased, after the injury, superficial erosion And blisters, often secondary infections, healing very slowly, self-pigmentation and micro-concave scars after healing, skin damage only occurs in skin exposed parts, facial and hand skin, and skin color is more common, hirsutism in women Patients are often very obvious, especially in the ankle, hair rims, severe chronic skin damage, infections and scars can be disfigured.

Most patients have symptoms gradually reduced for several months, and finally disappear completely. Acute attacks can lead to death, abdominal pain, nervous system symptoms and episodes of mental symptoms can be induced by barbiturates, sulfa drugs, drinking and Estrogen and the like can also be induced, and the symptoms of acute intermittent porphyria are the same, and skin symptoms can persist.

Examination of mixed porphyria

1. Peripheral blood: generally normal.

2. Conventional: In the acute attack period and asymptomatic period, the protoporphyrin and coproporphyrin in the feces are obviously increased. Even if the symptoms are mild or in childhood, it is also found that the coproporphyrin is usually more than the urinary porphyrin. The ratio of the amount of porphyrin to coproporphyrin is >1.5:1.

3. Urine: In the acute attack, the ALA in the urine and the gallbladder are increased significantly, and sometimes the urinary porphyrin and the coproporphyrin are also increased, which may be caused by the weakening of the feedback inhibition of heme.

Diagnosis and diagnosis of mixed porphyria

For patients with acute exacerbation, there are skin photosensitivity symptoms, and it is easy to determine the diagnosis in combination with laboratory tests.

Patients with simple neurological symptoms must be differentiated from surgical acute abdomen, snoring, and polyneuritis. At the same time, a large amount of protoporphyrin and coproporphyrin are excreted in the feces of the patient, and the fecal porphyrin in the urine is also significantly increased, which can be associated with acute intermittent. Identification of sexual porphyria, such as only skin symptoms, according to the patient with or without liver disease and liver function, urinary fecal porphyrin is higher than urinary porphyrin to identify.

In acute attacks, it is necessary to distinguish it from acute intermittent porphyria. Protoporphyrin and erythropoietic porphyria have skin damage that is sensitive to sunlight. Symptoms appear from childhood, red blood cells and plasma. The increase of mesoporphyrins, red blood cells emit red fluorescence under ultraviolet irradiation, and mixed porphyria does not have these characteristics, the symptoms often appear in adolescence, delayed skin porphyria also has similar skin symptoms, fecal porphyrin and original The content of porphyrin is also increased, but the excretion of ALA and bilirubin in urine is not increased, and the family history is not obvious. Most patients have liver disease or chronic alcoholism, liver function damage, etc., which can be differentiated from mixed porphyria. .

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.