Cholinergic urticaria
Introduction
Introduction to cholinergic urticaria Mainly due to exercise, heat, nervousness, eating hot drinks or alcoholic beverages, the body's deep temperature rises, causing acetylcholine to act on mast cells. It appears as a circular papular wheal with a diameter of 2 to 4 mm in a few minutes after stimulation. There are varying degrees of redness around the body, often spreading in the upper part of the trunk and upper limbs. Conscious itch, tingling or burning sensation, sometimes only itchy and no skin lesions, can resolve with 0.5 to 1 hour. Occasionally accompanied by systemic symptoms caused by acetylcholine (such as salivation, headache, pulse slowness, dilated pupils and spastic abdominal pain, diarrhea), etc., severe dizziness can cause syncope. A skin test or a scratch test with 1:5000 acetylcholine can produce a wheal at the injection site, and a satellite-shaped small wheal can appear around it. basic knowledge The proportion of illness: 0.3% Susceptible people: no special people Mode of infection: non-infectious Complications: diarrhea, shock, laryngeal edema
Cause
The cause of cholinergic urticaria
More common in young people. Mainly due to exercise, heat, nervousness, eating hot drinks or alcoholic beverages, causing cholinergic nerve impulses to release acetylcholine, causing increased levels of cyclic guanosine monophosphate (cGMP) in basophils and mast cells Histamine and disease.
Prevention
Cholinergic urticaria prevention
Cholinergic urticaria should keep the body cool, avoid sweating, avoid heat, nervousness, eating hot drinks or alcoholic beverages. Some Chinese medicines, such as Shouwu, Poria, Ginseng, Astragalus, Ganoderma lucidum, Jujube, Ligustrum lucidum, Cuscuta, Schisandra, Polygonatum, Huai Yam, Codonopsis, etc., have anti-free radicals, improve immune function, promote metabolism, regulate nervous system. And a variety of functions such as the endocrine system, have obvious anti-allergic effects. People with allergies can choose one or two miso soups for tea.
Complication
Cholinergic urticaria complications Complications, diarrhea, shock, laryngeal edema
Urticaria-like vasculitis, accompanied by vomiting, diarrhea, abdominal pain and other symptoms, severe can cause shock, left heart failure, double upper limb pain and other symptoms, severe cases can cause laryngeal edema and suffocation and life-threatening.
Symptom
Cholinergic urticaria symptoms common symptoms itching skin red wind
It appears as a circular papular wheal with a diameter of 2 to 4 mm in a few minutes after stimulation. There are varying degrees of redness around the body, often spreading in the upper part of the trunk and upper limbs. Conscious itch, tingling or burning sensation, sometimes only itchy and no skin lesions, can resolve with 0.5 to 1 hour. Light cholinergic urticaria can occur in adolescents in normal times. Generally, the symptoms can subside after stopping exercise or calming, so it is not easy to attract attention. Occasionally accompanied by systemic symptoms caused by acetylcholine (such as salivation, headache, pulse slowness, dilated pupils and spastic abdominal pain, diarrhea), etc., severe dizziness can cause syncope. A skin test or a scratch test with 1:5000 acetylcholine can produce a wheal at the injection site, and a satellite-shaped small wheal can appear around it.
Examine
Examination of cholinergic urticaria
According to the repeated appearance of the skin, the rapid wheal, itching, leaving no traces, and the characteristics of various types of urticaria are easy to diagnose, but should be identified in the following diseases, if necessary, laboratory tests (including chest X-ray) Check abdominal B ultrasound, etc.) and related tests (such as exercise, hot water, sunlight, ice), allergen testing, etc. to further clarify the cause.
The following laboratory tests can be performed if the clinical symptoms are difficult to diagnose or if the cause is further sought.
1. Suspected rheumatism caused by urticaria can check erythrocyte sedimentation rate, anti-nuclear antibodies, etc., serum complement determination, skin biopsy is helpful for the diagnosis of urticaria caused by complement activation.
2. For cold urticaria, syphilis serum test should be carried out to test cold globulin, cold fibrinogen, cold hemolysin and ice test, anti-nuclear antibody and other tests.
3. Solar urticaria should be checked for feces, urinary porphyrins, etc., should be distinguished from SLE.
4. Suspected to be related to infection, or a history of hepatitis in the liver or medical history at the time of physical examination, feasible blood routine, hepatitis B antigen, antibody test, stool eggs, fungi, X-ray examination of the lesion.
5. If thyroid disease is suspected, anti-microsomal thyroid antibody-related tests should be performed.
6. If you suspect that you are allergic to inhalation or ingestion, you should take an allergen test. If it is positive, you can take desensitization treatment.
7. Patients with serum urticaria have fever and joint pain. ESR should be examined. For example, erythrocyte sedimentation rate has important diagnostic value.
8. In addition to the obvious low-complementemia in the onset of urticaria vasculitis, the subunit Cla of serum Cl is significantly reduced, C4, C2 and Cg are moderately to severely reduced, and circulating immune complexes and low molecular weight Clq precipitates appear in serum. Direct immunofluorescence showed immunoglobulin and complement deposition in the skin wall of the skin.
9. Autoimmune chronic urticaria can detect autoantibodies, using its own serum skin test: routine blood draw in a sterile tube for 30min, centrifugation, take serum 100l to the patient for intradermal test, with normal saline as a control, such as 1h After the local appearance of the wind group diameter greater than 9mm is positive, other such as histamine release test, immunoblotting and enzyme-linked immunosorbent assay can be used.
Angioedema, especially hereditary angioedema, should be used for serum complement examination. It should be determined as the fourth component of complement (C4). If C4 is low, there may be a lack of complement first component esterase inhibitor (ClINH). Stage C4 is significantly lower than normal, and is lower than normal in the remission period. Even if there is no family history, the disease can be diagnosed. Conversely, if C4 is normal, the disease can be denied.
Chronic urticaria histopathology: simple local edema, serous exudation of the upper nipple and dermis, papilledema, a small amount of lymphocyte infiltration around the blood vessels, but infiltration can also be dense and mixed with eosinophils.
Diagnosis
Diagnosis and identification of cholinergic urticaria
According to young people, often induced by exercise, heat, nervousness, eating hot drinks, etc., manifested as small wind group, itching, sometimes with systemic symptoms of acetylcholine such as salivation, headache, abdominal pain, diarrhea, exercise or thermal bath stimulation, intradermal injection Nicotinic picrate or vinegar bile salt-induced wheal can be diagnosed.
