Allergic purpura is a systemic aseptic inflammation of the vessels of the microcirculatory bed with a predominant lesion of the skin, joints, gastrointestinal tract and renal glomeruli. It proceeds with the phenomena of hemorrhagic or urticaria rash, arthralgia, abdominal pain syndrome, hematuria and renal insufficiency. Diagnosis is based on clinical symptoms, laboratory data (blood, urine, coagulogram), examination of the gastrointestinal tract and kidneys. The basis of treatment of vasculitis is therapy with anticoagulants, angiaggregants. In severe cases, extracorporeal hemocorrection, glucocorticoid therapy, anti-inflammatory, cytostatic treatment are used.
ICD 10
D69.0 Allergic Purpura
Meaning
Allergic purpura (AP, Schenlein-Henoch disease, hemorrhagic vasculitis, capillarotoxicosis) is one of the most common hemorrhagic diseases today. In essence, it is an allergic vasculitis of a superficial nature with damage to small arterioles, venules, as well as capillaries. In the International Classification of Diseases (ICD), the disease is called “allergic purpura”. Schenlein-Genoch disease occurs mainly in childhood – from 5 to 14 years. The average prevalence among children of this age is 23-25 cases per 10 thousand. Persons aged 7-12 years are most susceptible to the disease. In children under 3 years of age, only isolated cases of purpura are known.
Causes
The etiological aspects have not been fully studied, it is only known that in most cases the pathology is infectious and allergic in nature. There is a seasonal dependence ‒ the greatest incidence is recorded in the wet and cold season. Long-term observations made it possible to identify common trigger factors preceding the development of clinical manifestations. These include:
- Infectious diseases. In most patients, the manifestation of vasculitis is preceded by an acute respiratory tract infection (tracheobronchitis, tonsillitis, rhinopharyngitis). The most common nasopharyngeal flushes are beta-hemolytic streptococcus, Staphylococcus aureus, E. coli, adenovirus, HSV types 1 and 2. A smaller proportion of sick children are infected with cytomegalovirus, Epstein-Barr virus, chlamydia, Mycobacterium tuberculosis, hepatitis B virus.
- Drug therapy. In rheumatology, there are reports of the development of allergic purpura against the background of the use of pharmacopreparations: antibiotics (penicillins, macrolides), NSAIDs, antiarrhythmic agents (quinidine). Preventive vaccination, carried out immediately after the transferred acute respiratory viral infection, can provoke the phenomena of allergic purpura.
- Allergic burden. In the anamnesis of patients with AP, there are often indications of the presence of various types of allergies (drug, food, cold). Patients often suffer from allergic dermatitis, pollinosis, allergic rhinitis or manifestations of exudative catarrhal diathesis.
- Other endogenous and external causes. Among the producing factors may be hypothermia, excessive insolation, insect bites, injuries. In some patients, the manifestation of the disease occurs against the background of pregnancy, diabetes mellitus, malignant tumors, cirrhosis of the liver.
In many observations, the causal factor that caused the occurrence of vasculitis cannot be established. A number of authors suggest that the effect of provoking factors leads to the development of allergic purpura only in cases when it is carried out against the background of a genetic predisposition of the body to hyperergic immune reactions.
Pathogenesis
The mechanism of development of allergic purpura is based on the formation of immune complexes and an increase in the activity of proteins of the complement system. Circulating in the blood, they are deposited on the inner surface of the wall of small vessels (venules, arterioles, capillaries), causing damage to it with the occurrence of an aseptic inflammatory process. Inflammation of the vascular wall, in turn, leads to an increase in its permeability, deposition of fibrin and thrombotic masses in the lumen of the vessel, which causes the main clinical signs of the disease — skin hemorrhagic syndrome and microthrombosis of the vascular bed with damage to the gastrointestinal tract, kidneys, joints.
Classification
In the clinical course of capillarotoxicosis, there is an acute phase (initial period or exacerbation) and a phase of subsiding (improvement). According to the prevailing symptoms, the disease is classified into the following clinical forms: simple, rheumatoid (articular), abdominal and lightning. In accordance with the nature of the course, acute (up to 2 months), prolonged (up to six months) and chronic AP are distinguished. According to the severity of clinical manifestations, vasculitis is distinguished:
- Mild. There is a satisfactory condition of patients and the non-abundant nature of the rash, arthralgia.
- Medium degree. The patient’s condition is of moderate severity, rashes are abundant, arthralgia is accompanied by changes in the joints according to the type of arthritis, periodic abdominal pain and microhematuria are noted.
- Severe degree. There is a serious condition of the patient, excessive discharge rashes with necrotic areas, angioedema, nephrotic syndrome, macrohematuria and gastrointestinal bleeding are observed, acute renal failure may develop.
Symptoms
For the clinic of allergic purpura, an acute onset with an increase in temperature to subfebrile or febrile digits is typical. However, there may be no temperature rise. The skin syndrome is noted at the very onset of the disease and is observed in all patients. It is characterized by diffuse spotty-papular hemorrhagic elements of various sizes (more often small) that do not disappear when pressed. In some cases, urticaria rash is observed. Rashes are usually located symmetrically on the skin of the shins, thighs and buttocks, in the area of large joints, less often on the skin of the arms and trunk. The abundance of rashes often correlates with the severity of vasculitis. With its most severe course, necrosis develops in the center of some elements of the rash and an ulcer forms. The resolution of the rash ends with a long-lasting hyperpigmentation. With a chronic course of AP with frequent relapses, peeling occurs on the skin after the rash disappears.
Articular syndrome develops in 70% of patients. Joint lesions may be short-term in the form of mild arthralgia or persist for several days with severe pain syndrome, accompanied by other symptoms of arthritis (redness, swelling) and leading to limited movement in the joint. Typical is the volatile nature of the lesion involving mainly large joints, more often knee and ankle. Articular syndrome may appear in the initial period of vasculitis or occur later. Often it has a transient character and never leads to permanent deformation of the joints. Abdominal syndrome may precede or accompany skin-joint manifestations. It is manifested by abdominal pain of varying intensity – from moderate to paroxysmal by the type of intestinal colic. Patients often cannot specify the exact localization of pain, complain of stool disorders, nausea and vomiting. Abdominalgia may appear several times during the day and go away spontaneously or in the first few days of treatment.
Renal syndrome occurs in 25-30% of patients and is manifested by signs of chronic or acute glomerulonephritis with varying degrees of hematuria. A number of patients have a nephrotic symptom complex. The defeat of other organs in allergic purpura occurs quite rarely. It can be hemorrhagic pneumonia in the form of a cough with streaks of blood in the sputum and shortness of breath, hemorrhages in the endocardium, hemorrhagic pericarditis, myocarditis. Damage to the vessels of the brain is manifested by dizziness, irritability, headache, epiprimes and can cause the development of hemorrhagic meningitis.
Complications
Kidney damage is the most persistent syndrome of allergic purpura, can be complicated by malignant glomerulonephritis and chronic renal failure. In severe cases of allergic purpura, gastrointestinal bleeding occurs, accompanied by bloody vomiting and the presence of blood in the stool, pulmonary bleeding, hemorrhages in the brain substance (hemorrhagic stroke). Massive blood loss can lead to collapse and anemic coma. Complications of abdominal syndrome are less common and are represented by intestinal intussusception, peritonitis, thrombosis of mesenteric vessels, necrosis of part of the small intestine. The highest frequency of deaths is recorded in the lightning-fast form of AP.
Diagnostics
When conducting diagnostics, the rheumatologist takes into account the patient’s age, studies these factors, compares clinical and laboratory data, and excludes other diseases. With the development of renal syndrome, the patient needs a consultation with a nephrologist, in the presence of abdominal pain – a consultation with a gastroenterologist and a surgeon. The diagnostic panel includes:
- Hematological tests. In the general blood test, as a rule, there are nonspecific signs of moderate inflammation (leukocytosis and a slight increase in ESR), an increase in the number of platelets and eosinophils. A biochemical blood test shows an increase in immunoglobulin A and CRP. The results of the coagulogram are of great diagnostic importance. The absence of data in it for clotting disorders in the presence of clinical signs of hemorrhagic syndrome indicates in favor of AP.
- Urine and stool tests. In the analysis of urine, hematuria, proteinuria, and cylindruria are detected. Patients with renal syndrome are shown monitoring changes in urine analysis, urine biochemistry, Zimnitsky, Nechiporenko samples. To diagnose hidden gastrointestinal bleeding, a stool analysis for hidden blood is performed.
- Instrumental diagnostics. In order to assess the condition of the target organs, kidney ultrasound, ultrasound of the renal vessels is performed. To exclude organic causes of bleeding from the digestive tract and bronchi, it is advisable to conduct an abdominal ultrasound, gastroscopy, bronchoscopy.
- Biopsy with histology. In severe diagnostic cases, a skin or kidney biopsy is indicated. Histological examination of the biopsy reveals characteristic changes: deposits of immunoglobulin A and CEC on the endothelium and in the thickness of the vascular wall of venules, arterioles and capillaries; the formation of microthrombs; the release of blood elements outside the vessel.
The abdominal form of allergic purpura should be differentiated from other causes that cause the appearance of symptoms of “acute abdomen”: appendicitis, penetration of stomach ulcers, acute cholecystitis, pancreatitis, intestinal perforation in ulcerative colitis, etc. It is also necessary to exclude thrombocytopenic purpura, hemorrhagic syndrome in infectious diseases (hemorrhagic fevers, influenza), leukemia, rheumatoid arthritis, Still’s disease, acute glomerulonephritis, systemic vasculitis.
Treatment
In the acute phase of allergic purpura, patients should observe bed rest and a hypoallergenic diet, limit the use of fluids and salt, exclude the use of antibiotics and other medications that can increase the sensitization of the body. The main directions of therapy depend on clinical manifestations, so it is advisable to consider them individually:
- For any syndromes. The basis of basic therapy for all forms of HBV is the appointment of disaggregants (dipyridamole, pentoxifylline) and fibrinolysis activators (nicotinic acid). Preparations of these groups prevent platelet aggregation, improve microcirculation and interstitial perfusion. Often, heparin and other anticoagulants are included in the basic scheme.
- With skin syndrome. Therapy involves the use of sulfasalazine, colchicine. The use of prednisone is still a controversial issue among doctors. It is possible to prescribe it in severe cases of AP. In the absence of the effect of corticosteroid therapy, cytostatics are the reserve drugs.
- With articular syndrome. Pronounced arthralgias are stopped by anti-inflammatory therapy (indomethacin, ibuprofen). Additionally, aminoquinoline derivatives (chloroquine) may be prescribed.
- With renal syndrome. High doses of glucocorticoids and cytostatics are prescribed. It is possible to use ACE inhibitors, angiotensin II receptor antagonists, the introduction of normal human immunoglobulin, electrophoresis with nicotinic acid and heparin on the kidney area. In the terminal stage of CRF, hemodialysis or kidney transplantation is required.
- With abdominal syndrome. Intense pain syndrome serves as an indication for intravenous administration of prednisone, rheopolyglucine, and crystalloids. With the development of surgical complications (perforation, intussusception), surgical tactics are used.
Severe course of the disease is an indication for extracorporeal hemocorrection (hemosorption, immunosorption, plasmapheresis). Many authors note the ineffectiveness of antihistamines in the treatment of AP. However, their use may be justified in patients with an allergic history. When the disease is associated with food allergies and the presence of abdominal syndrome, enterosorbents are additionally prescribed.
Prognosis and profilktics
Mild forms of allergic purpura are prone to spontaneous healing after the first attack of the disease – their prognosis is favorable. With a lightning-fast form, the death of patients can occur in the first few days from the onset of the disease. Most often this is due to damage to the vessels of the central nervous system and the occurrence of intracerebral hemorrhage. Another cause of death may be severe renal syndrome, leading to the development of uremia. In order to prevent allergic vasculitis, it is recommended to sanitize chronic infectious foci of ENT organs, deworming with worm infestations, exclusion of contact with known allergens and uncontrolled medication intake.