It was an early Monday morning when Mrs. M. anxiously paced in front of the office waiting for it to open. She had her 6-year-old son and was holding him in her arms. The front office staff put her in a room and told me she was here. They quickly got his chart and took his temperature. As I was walking in the room I noticed that he didn’t have a fever.
Before I could say a word, she apologized for just showing up, but she was very worried. John, her son, was sitting in a chair not looking particularly ill but was quiet and appeared a bit pale. He was in his pajamas and patiently listened as I gathered the history. On Wednesday, five days before, he said that he didn’t feel well and just laid around the house. This was out of character for him, especially since he was on school vacation. That night she noticed a small red rash on his legs. When she asked him about it he said it had been there for a few days. The rash consisted of small (less that 1 millimeter) dark red spots of varying sizes that were in no particular distribution. They were primarily on his buttocks and lower legs. They were not raised and did not itch. That night he complained of a stomachache and didn’t want to eat dinner.
Over the next two days the rash spread minutely, but he now had new lesions on his arms around the elbows. The earlier spots on the legs had grown in size and had taken on a purplish hue. His stomachache was intermittent and crampy at times. Of course, by now it was the weekend and mom thought she would make an appointment for Monday to have this checked out. But on Sunday afternoon, as he was lying on the couch, she asked him to get up. He walked slowly and stiffly like an old man. She was shocked to see that his knees were swollen and sore. His temperature showed that he did not have a fever. That night after he went to bed, she got on the computer and did a search. She was convinced that he had leukemia or some form of malignancy, hence the panicked rush to the office.
Looking at John’s list of symptoms and complaints, mom was not incorrect to worry about a malignancy or serious bacterial infection. But after the history and examination it was clear that John had Henoch-Schoenlein Purpura (HSP), which is a not uncommon form of vasculitis that affects primarily children. HSP may have four major components. There is the ”purpuric” rash, swollen joints, gastrointestinal symptoms and kidney involvement.
No one knows the exact cause of HSP. But it is thought to be the response of an overzealous immune system to some trigger. The potential triggers that have been implicated include a preceding viral or bacterial infection, insect evenomation, certain drugs or even cold weather. It is well documented that over 50% of HSP patients have had a recent upper respiratory infection. In response to these ”triggers”, there is the deposition of antibodies (lgA) in the walls of small blood vessels causing a vasculitis or inflammation of these vessels.
When they occur on the skin they cause the rash or purpuric lesions. These appear predominantly on the legs and buttocks and less so on the arms or face. They start as small reddish spots that gradually evolve into larger purplish “splotches” that may be slightly raised. The skin rash is the hallmark of HSP and occurs in almost 100% of cases. The rash will gradually resolve over time. It may take weeks for it to finally disappear.
Around 80% of HSP patients will have swollen and sore joints. The typical joints involved are the larger weight bearing ones such as the knees and ankles. They are usually swollen and sore, but they are typically not red or warm to touch. The elbows and wrists may become involved but this is less likely.
Gastrointestinal (GI) symptoms occur in around 60% of patients with HSP. These may include a colicky or crampy pain, nausea and/or vomiting. This is due to the deposition of the antibodies in the small blood vessels of the intestine itself. The pain is usually intermittent and may be severe at times. One major complication is that the swollen wall of the intestine may act as a leading point whereby the intestines may “telescope” on itself causing an obstruction known as intussusception. This can cause bloody stools and is a medical emergency, and must be dealt with urgently.
The kidney is involved in 20%-50% of patients with HSP. This is also due to the deposition of antibodies in the wall of the tiny blood vessels of the kidney. It may lead to the spillage of blood and/or protein in the urine. Usually it is detected by a urinalysis, because even if there is blood, it may not be detected by the naked eye. The kidney involvement, should it occur, may not show up for weeks--long after the rash and joints have cleared up. This must be followed closely for at least two months.
HSP primarily affects children. Over 90% of cases are in youngsters under ten years of age. It affects boys more than girls, and is more common in Caucasian and Asian people than in Hispanics or African-Americans.
The history of illnesses is fascinating and HSP is no exception. Schoenlein was a German physician who lived in the early 1800’s. In 1837 he described a group of children who had a rash of the legs, and joint swelling and pain. His protete and student, Dr. Henoch, described a group of children with intestinal complaints and kidney involvement years later. After some time the medical community recognized that they were describing the same illness, and so it became identified as HSP. What is fascinating is that in 1801, a physician named Heberden wrote of a five-year-old child that had “bloody points” on his legs, abdominal pain, blood in his stools and urine, and painful edema of the joints. Sound familiar?
HSP is a self-resolving illness and the treatment is mainly supportive. Non-steroidal anti-inflammatory drugs help with the joint pain; most children will limit their activity accordingly and will rest as needed. If there is significant abdominal pain, a short course of steroids should be considered to minimize the risk for intussusception. Most cases resolve without incidence over a few weeks. The only caveat is that the kidney involvement may not show up for weeks after the rest of the symptoms have cleared up. So the urines should be checked up for two months.
John had an uneventful recovery of his HSP. Within two weeks the rash had subsided. He had rare abdominal complaints and was eating like a champ. The joints were 100% back to normal as was his activity. I checked his urine weekly. After the third week he had some blood and protein in his urine sample. This persisted for three weeks and went from 1+-to-trace-to negative. It has been negative since and we are six weeks out from his initial symptoms.