Why it occurs and what happens to the vessels
The triggering factor is most often an upper respiratory tract infection, less often an intestinal infection, medication, an insect bite or vaccination. In a predisposed child, the immune system produces an excess amount of immunoglobulin A, which forms complexes and settles in the walls of the smallest vessels of the skin, intestines, joints and kidneys. Inflammation develops around them, the wall becomes permeable, red blood cells escape into the tissue - this is how a characteristic hemorrhagic rash appears. The blood coagulation system is not impaired.
- Previous respiratory infection 1–3 weeks before illness
- Streptococcal throat infection
- Intestinal infections
- Reaction to drugs
- Deposition of IgA-containing immune complexes in blood vessels
- More common in autumn and winter
Main manifestations
The classic tetrad includes cutaneous, articular, abdominal and renal syndromes, but the combination varies. The rash almost always appears: small red-purple spots and dots, often on the legs, feet, buttocks, symmetrically, intensify when walking and standing. The joints - usually the ankles and knees - swell and hurt, but do not leave permanent deformation. Abdominal pain is cramping and sometimes precedes a rash, making diagnosis difficult. Kidney damage may appear later, weeks later.
- Symmetrical palpable purpura on the legs and buttocks
- The rash does not go away with pressure
- Swelling and pain in the ankle and knee joints
- Cramping abdominal pain, nausea
- Blood in the stool with severe intestinal damage
- Changes in urine analysis: red blood cells, protein
- In boys, swelling of the scrotum is possible
Diagnostics
The diagnosis is primarily clinical: a characteristic rash on the legs combined with abdominal pain, joint pain, or changes in urine. Tests are needed to rule out other causes of bleeding and evaluate organ involvement. In hemorrhagic vasculitis, the platelet count and coagulation parameters remain normal - this is an important difference from blood diseases. Be sure to repeat the urine test: renal manifestations may occur delayed. For abdominal pain, an ultrasound examination is performed.
- Complete blood count with platelets
- Coagulogram is normal for this disease
- General urine analysis, repeated over time
- C-reactive protein, creatinine
- Immunoglobulin A
- Throat swab for streptococcus
- Ultrasound of the abdominal organs
- Skin or kidney biopsy in unclear cases
Treatment
In mild cases, no specific treatment is required: rest in the acute period, sufficient drinking, a gentle diet for abdominal pain and pain relief for joint pain with drugs selected by the doctor are needed. Glucocorticoids are prescribed for severe abdominal syndrome, severe damage to the joints or kidneys. Nephritis may require immunosuppressive therapy and observation by a nephrologist. Antibiotics are used only for confirmed bacterial infection. Bed rest for the entire period of the rash is not necessary, but the load is limited.
- Rest and limitation of exercise in the acute period
- Painkillers as prescribed by a doctor
- A gentle diet for abdominal pain
- Glucocorticoids for severe forms
- Immunosuppressive therapy for nephritis
- Treatment of the source of infection when identified
- Refusal to self-administer medications that could trigger the disease
Observation and forecast
In most children, the disease ends in recovery within four to six weeks, although wave-like sleepiness during this period is common and does not mean deterioration. The main reference point for prognosis is the kidneys. That is why the urine test is repeated according to a schedule: first often, then less often, for a total of at least six months after the episode. In adults, the disease is more severe and more often affects the kidneys. Relapses are possible, especially against the background of a new infection.
- Control of urine analysis according to the scheme prescribed by the doctor
- Blood pressure measurement
- Observation by a nephrologist for persistent changes in urine
- Timely treatment of throat infections
- Discussing the timing of vaccination with your doctor
- Repeated treatment for new rashes or swelling