Symptoms of allergic purpura, 5 symptoms to watch out for

Allergic purpura mainly occurs throughout the body, often in the thighs. Severe allergic purpura will affect the intestines, and it will be difficult to cure at this time. When allergic purpura occurs, the patient's skin will develop brown-red maculopapular rashes, and there will be symptoms of itching or pain.

1. Skin

The typical rash is brown-red maculopapules that protrude from the skin surface, do not fade when pressed, appear alone or fused together, and are symmetrically distributed. It is more common on the extensor sides of the limbs (especially the lower limbs) and buttocks, and may be accompanied by itching or pain. It recurs repeatedly and appears in batches. Pigmentation may remain after it subsides. In addition to purpura, complications such as urticaria, angioedema, erythema multiforme or ulcer necrosis may also occur. Occasionally, purpura may occur on the oral mucosa or conjunctivae of the eyes.

2. Kidneys

Hematuria (gross or microscopic), nephrotic syndrome, mild proteinuria, acute nephritis with hypertension. Kidney damage usually occurs within 3 months of the onset of the rash.

3. Gastrointestinal tract

Abdominal pain is common and is often colic, caused by extravasation of blood into the intestinal wall. The pain is obvious around the navel and right lower abdomen, and may also spread to the entire abdomen, but there is generally no tension in the abdominal muscles. The tenderness is mild and may be accompanied by nausea, vomiting, diarrhea and black stools. Irregular intestinal peristalsis may lead to intussusception, and a mass may be palpable, which is more common in children. Intestinal perforation may occasionally occur. If it is not accompanied by skin purpura, it is often misdiagnosed as "acute abdomen". Male patients may also experience scrotal edema and pain. Less common include pancreatitis, intestinal perforation, gallbladder vasculitis, and protein-losing enteropathy. Hepatomegaly of unknown cause occurs in 10% of patients.

4. Joints

Joint pain and arthritis with swelling around the joints. The most common joints are the knees and ankles and are more common in adults. The pain is usually out of proportion to the symptoms. The joint space is normal, transient and self-limited, and there are no sequelae.

5. Others

Acute scrotal edema secondary to scrotal vascular inflammation and hemorrhage occurs in 2% to 35% of boys. Lung involvement accounts for 95%. Other rare complications include cardiac involvement, intramuscular hemorrhage, and ureteral vasculitis with stenosis. Occasionally, central nervous system (convulsions and coma) manifestations, respiratory system (laryngeal edema, asthma), circulatory system (myocarditis, pericarditis) symptoms, as well as testicular bleeding and swelling have also been reported. Pulmonary hemorrhage is rare but can be fatal.