Allergic purpura

Allergic purpura is a type of commonly seen vessels disease with abnormal (allergic) reaction in hemorrhage. It happens due to the organism has developed allergical reaction towards certain allergens, it will cause widespread of inflammation of small vessels (vasculitis) that leads to weaken and increased permeability of small veins and capillaries, accompanied by diffused bleeding and edema. The main clinical manifestations are skin purpura (red spots on skin), mucosal bleeding along with skin rash, athralgia (pain in joint), abdominal pain and damage to the kidneys. This disease arises more common in child and teenagers, male more than female and often in season of spring and autumn. [Pathogenic factor] It is often difficult to determine the direct cause of this disease, related factors are such as:(1) Infection: bacteria (mostly by ?­hemolytic streptococcus which affects the upper respiratory tract, staphylococcus, pneumococcus, mycobacterium tuberculosis), virus (german measles, chicken pox, measles, flu) and the intestinal tract parasite.(2) Food: fish, prawn, crab, egg, dairy products and so on which contain foreign proteins.(3) Drugs: antibiotic (blue, chain, red, chloromycetin), sulfonamides, anti-pyretic and analgesic (e.g quinine) and etc.(4) Other: cold, pollen, insect bite, vaccination and etc.The above factors will induce the reaction of the antigen - antibody complex (immune complex); this complex will deposit at the vessels wall or on the basement membrane of the kidney glomeruli. Hence, resulted in complement activation and release of allergic mediators which damage capillaries, small veins, cause widespread of capillary inflammation and even yields the appearance of necrosis phlebitis (inflammation of veins) that leads to weaken and increased permeability of vessels wall, causes hemorrhage and edema of the subcutaneous tissue, mucosa and internal organs. The digestive tract and joints may have the similar changes. The pathological changes of the kidney include light degree of focal nephritis, while severe patients may also have focal necrosis of glomerulus capillaries or damage of the whole kidney. Some scholars thought that this sickness is related to acute allergical reaction where abundant of IgE is attached to the adipose cells and cause the latter to release allergen mediators (certain biological substances) that resulted in damages as mentioned above. [Clinical manifestations] Often, there is infection of upper respiratory tract about 1-3 weeks before the onset of this disease. The main symptom is mostly - the skin purpura, a minor cases will experience athralgia, abdominal pain, waist pain or hematuria (blood in urine), black stool and etc before the disease occurence. Basically, pathological changes in the affected region implicates the type of the allergic purpura.(1) Purpura type- most common. It is characterized by non-bacterial inflammation of the dermis and small veins; vessels wall may have focal necrosis and thrombus formation. Generally, it is shown as spots and patches of bruises that seen mostly at lower extremities and buttock region with symmetrical distribution, appear in sequences, different sizes of spots, red-purplish colour and may fuse with the skin by patches or slightly elevated from the skin surface. It yields hemorrhagic measles or small papula and etc, accompanied by slightly itches. In serious condition, it may fused and formed large hematoma with center of necrosis. The spots and patches of bruise shall disappeared gradually in several days, but it may also repeatedly appear; minority cases may also have regional vascular edema at eyes, face, mouth, lips, hand, foot and etc.(2) Abdominal type (Henoch purpura). The main sign is abdominal pain around navel or lower region of abdomen with periodical spasm (colic)or continuos dull pain; may accompanied by nausea, vomitting, diarrhea and blood in stool (melena). As a result of secretion of hemorrhagic serous fluid diffused into the intestinal wall, leads to edema and bleeding under the mucose membrane, thus causing irregular peristalsis movement and formation of folds. If this symptom occurs before the skin purpura, it is always easily misdiagnose for acute abdominal syndrome.(3) Joint type (Schonlein purpura). It s main feature is swelling and pain in joint, mostly seen in knee, foot and big joints; joint cavity may accumulate fluid but will not transformed into pus. The pain manifested repeatedly, irradiate and accompanied by redness, swelling and movement disturbances; in majority, it shall disappear in few months, reabsorption of fluid without abnormality.If it happens before purpura, it is often misdiagnose for rheumatic arthritis.(4) Renal type-- also called purpura nephritis, often seen in youth, always happens 1 week after the appearance of purpura, sometimes delayed till 7-8 weeks. The clinical manifestations are such as proteinuria, hematuria, cylindruria and sometimes came along with edema; generally, it restores in several weeks, but also may relapsed and prolonged for a few months. In some cases, the pathological changes may involve the entire kidney and develop into chronic nephritis or renal sickness syndromes, uremia may or may not happen due to organism s functional state.(5) Mixed and rare type. If above mentioned types take place more than 2 types simultaneously, it is called mixed type. The combination of abdominal and joint type is called Henoch-Schonlein purpura. The other pathological changes affecting the central nervous system, respiratory system and so on may have corresponding symptoms; in some cases, one may have optic nerve atrophy (degeneration), iritis or conjunctivitis and retina bleeding. The diagnosis of this disease is mainly based on the skin purpura, some patients may yield positive test result in capillary brittleness examination. While bleeding time, coagulation time, platlet count, blood clot retraction time and bone marrow examination are normal. When there is multi-infection, there will be leukocytosis; when there is parasite invasion, there will be eosinophilia; if affects the kidney, there will be hematuria, proteinuria or cylindruria; if affects the digestive tract, there will be present of blood in stool (micro or macro). In traditional chinese medicine (TCM) studies, this disease belongs to the category of ban (patch) and zhen (macule). Generally, it is due to weakness of Yin and strengthen of Yang with aggresive of heat in blood, but it may also belongs to weakness, cold and etc. For patients with symptoms of heat , it is treated by clearance of heat, disintoxicating, cooling blood with supporting its Yin , stoppage of bleeding, elimination of bruise and so on; while for those with weakness symptoms, it is treated by restoring Qi (vital energy), supporting blood, nourishing the spleen, heart and liver and etc., if it is accompanied by wind, heat or moist heat , substances that eliminate wind , heat and moist must be added accordingly.[Clinical treatment results]There were 986 cases adopted TCM; among them, 981 cases recovered completely (completely disappearance of skin purpura, accompanied symptoms disappeared, no relapsing in 2 years follow-up visit), averagely 3-15 days seen effectiveness.