allergic skin vasculitis
Introduction
Introduction to allergic skin vasculitis Allergic cutaneous vasculitis is a group of vasculitis diseases characterized by small blood vessels, venules, capillaries and small arteries, especially inflammation of the posterior capillaries. The muscle arteries are not involved, the clinical manifestations are mainly cutaneous vascular lesions, and the vascular lesions of the external organs are lighter, involving the joints and the kidneys, and do not constitute irreversible organ dysfunction and life threatening. basic knowledge Sickness ratio: 0.05% Susceptible people: more common in young people Mode of infection: non-infectious Complications: systemic idiopathic telangiectasia
Cause
Causes of allergic skin vasculitis
Drug factor (35%)
The incidence of this disease is more and more complicated. It is generally believed to be caused mainly by drugs and infections. The most common pathogenic drugs are barbiturates, phenothiazines, sulfonamides, penicillins, iodides, aspirates. Forest and allogeneic proteins.
Infection factor (25%)
Infection is also an important factor, such as viruses, streptococcus, tuberculosis, and leprosy. Fungi and protozoa are also considered to be a causative factor. Insecticides, herbicides and petroleum products are also associated with this disease.
Disease factor (15%)
In addition, intrinsic diseases such as frozen proteinemia, hyperglobulinemia, systemic lupus erythematosus, rheumatoid arthritis, etc. can also cause the disease.
Pathogenesis
The sensitizing substance enters the body as an antigen, and combines with the antibody to form an immune complex, which is deposited on the blood vessel wall to cause vascular damage.
Prevention
Allergic skin vasculitis prevention
Prevention: This disease should pay attention to avoid the invasion of outside wind, humidity, cold, heat and evil spirits. Patients should take appropriate rest and raise their limbs to reduce local edema.
The disease is closely related to type III allergy. For some patients with obvious incentives, it should avoid contact with predisposing factors and prevent the cause.
Other patients with unclear etiology, in addition to active treatment, need to be strictly screened to find out the cause and take preventive measures.
Complication
Allergic skin vasculitis complications Complications systemic idiopathic telangiectasia
Can be associated with visceral involvement, such as the kidneys, gastrointestinal, nervous system and so on.
Symptom
Allergic skin vasculitis symptoms common symptoms, hemorrhage, fatigue, diplopia, rash, abdominal pain, wheal proteinuria
More common in young people, the history of acute bacterial or viral infection often 1 to 2 weeks before the onset of the disease, most patients only skin involvement, a small number can affect the internal organs.
The skin lesions start from miliary to mung bean big red maculopapular rash and purpura, which gradually enlarge, can become blister or blood blister, can also be dark red nodules, can form ulcers after nodular necrosis, overlying dry blood stasis, Ulcers often leave atrophic scars after healing. Many kinds of lesions often exist at the same time, but they are characterized by purpura, nodules, necrosis and ulcers. The rash occurs in the calves, the ankles and the upper limbs, and is symmetrically distributed. The trunk, conscious pain or burning sensation, some patients may be associated with visceral involvement, such as kidney, gastrointestinal, nervous system, etc., called allergic skin-systemic vasculitis.
Examine
Examination of allergic skin vasculitis
Platelet count can be reduced, erythrocyte sedimentation rate can be increased, white blood cell count can be increased, and eosinophils can be increased.
Histopathology: Capillary vasculitis and vasculitis of the dermal papilla and reticular layer, vasodilation, swelling of endothelial cells, narrowing or even occlusion of the lumen, fibrin-like degeneration or necrosis of the vessel wall, neutrality of the blood vessels and their surroundings Granulocyte infiltration.
Diagnosis
Diagnosis and diagnosis of allergic cutaneous vasculitis
According to the medical history, clinical manifestations and laboratory tests can confirm the diagnosis.
Need to be differentiated from papular necrotizing tuberculosis, the latter has a history of tuberculosis or tuberculosis, tuberculin test positive, skin lesions with follicular hard papules, nodules and ulcers, no purpura, blood blisters, wheal Wait for a rash.
1, chronic, repeated attacks, mainly distributed in the lower limbs.
2, the rash is erythema, papules, cyanosis, small blisters, nodules, wheal, ulcers and other polymorphic damage.
3, white blood cell count increased, ESR increased.
4. The anti-"O" value is increased.
5, histopathology showed non-specific adipose tissue inflammation and dermal inflammation in the subcutaneous tissue.
