Mysterious rash

Proven content

A strange rash, or even a single inflammation, may not only be an allergy or an infectious disease such as smallpox or rubella. Increasingly, children are diagnosed with Henoch-Schönlein disease, also known as allergic purpura.

It is an autoimmune disease that affects boys twice as often as girls. The risk clearly decreases after the age of 11; however, cases of this disease are also reported in adults. Allergic purpura usually begins with a cold, angina or chicken pox, or shortly after recovery from this disease. However, it can also occur after some vaccinations (e.g. against measles and typhoid fever), insect bites, infection with the herpes virus. The beginning of the disease is always this moment of increased activity of the immune system. Antibodies correctly catch foreign antigens of viruses, bacteria, etc. and form the so-called immune complexes that should be quickly excreted from the body. In Schönlein-Henoch disease, this is where the wrong reaction takes place: the immune complexes are not removed, but instead end up in the blood vessels and build up in their walls. This, in turn, triggers an inflammatory response.

Symptoms of Schönlein-Henoch disease

The onset of the disease is inflammation of the capillaries, fine veins and arterioles. They become permeable to the blood, which is why the first symptom is most often a hemorrhagic rash or single ecchymoses, sometimes with edema. They occur in 99% of patients. Abdominal pain is a common symptom.

– In older children who dress and wash themselves, the disease can develop in hiding – says Urszula Orlik, a dermatologist. – The skin lesions that most often appear first develop mainly on the buttocks and legs. Usually they are not painful, so your child may not notice them at all. It happens that they do not even itch.

Unfortunately, this disease is not limited to skin lesions. Blood vessels leak blood not only in the skin but also, very often, in the kidneys and intestines. Parents may therefore notice hematuria or traces of blood in their baby’s stools. With very severe symptoms, the child may have anemia; fortunately, it usually passes without a trace a few weeks after recovering from the disease.

However, there are other problems as well: changes in the joints of the upper and lower extremities appear in three-fourths of patients, manifested by pain and clear swelling. Often parents assume that the child has sprained his leg; usually the changes concern the knee or ankle joints. Fortunately, they usually disappear after a few days without leaving a trace.

In more than half of children, the disease is accompanied by colic-like abdominal pain, sometimes with vomiting. Sometimes they are misdiagnosed, for example as appendicitis. So operations are carried out, of course, in this case completely unnecessary. Unfortunately, intestinal perforation can also occur, so children with abdominal discomfort in this disease are usually left in the hospital for observation.

However, the most dangerous symptom of Schönlein-Henoch disease are changes in the kidneys. The older the child, the greater the risk; problems occur in every second patient at the age of 8 and only in every fourth two-year-old. In one out of a hundred patients, they end up with chronic renal failure. Therefore, even if the disease manifested itself only as a rash and has passed without a trace, the child should be consulted at the nephrologist and have urine tests performed regularly, even six months after the symptoms of the disease have disappeared.

Diagnostics of Henoch-Schönlein purpura

“The diagnosis of the disease is based mainly on the clinical picture, there are no specific laboratory tests, write Ewa Szyguła-Kotala and her colleagues from the Chorzów Center of Paediatrics and Oncology in the work ‘Generalized form of Henoch-Schönlein purpura’. So far, no laboratory test has been described that could be unambiguously helpful in diagnosing, determining the severity and prognosis of the disease, as well as monitoring its treatment.

So it happens that the doctor sends the child to another specialist for consultation, so that he can confirm his diagnosis. With all three common symptoms, called here the big three, i.e. rash, joint discomfort and kidney problems, manifested by pain or hematuria, correct diagnosis is relatively simple. However, if one of the components is missing or only a rash is visible, even an experienced physician may have difficulties; then the child is usually sent to the hospital for observation and additional tests.

Of course, if Schönlein-Enoch disease is suspected, blood tests are also performed, but they may not show any changes. Often, morphology shows an increased number of leukocytes and eosinophils, i.e. eosinophils, which are cells of the immune system. Occasionally, ESR and platelet counts are also elevated. When a disease is suspected, the level of D-dimers is also checked, the number of which usually increases during the disease. Protein is often found in the urine in addition to blood.

Treatment of allergic purpura

Fortunately, the disease usually passes without a trace after 4-6 weeks. It is not known what causes it, so treatment is purely symptomatic. Of course, if the infection that started the disease still persists, it is treated like any other colds or strep throat. The doctor usually prescribes blood vessel sealing drugs, and in case of joint pain also anti-inflammatory drugs, and recommends a relaxed lifestyle.

– As most patients are 3-6 years old, it is precisely limiting their mobility, making them sit and lie down instead of running, which poses the greatest difficulties – says Teresa Hass, a pediatrician.

Children often go to hospital, where it is easier to control their behavior and monitor the development of the disease on an ongoing basis. In many cases, it is necessary to administer steroids that relieve symptoms but do not remove the disease itself. With large changes in the kidneys, immunosuppressants are also administered.

Half of the children relapse within two months of recovery; usually shorter and softer than the first attack. Further relapses occur in 10% of patients in the following months or even years. It is important that you talk to your doctor before giving any medicine to your child who has had this condition, especially before immunization. The vaccine may or may not cause the disease to come back.

“Children who have had kidney problems during the disease need to have their urine tested regularly, for as long as 2-3 years,” says Hass. – It happens that the failure develops slowly or that relapse affects only the kidneys, without causing a skin rash.

Read also: Know the allergy on your own skin – urticaria

Text: Liliana Fabisińska