Tag: vasculitis

Do Vaccines Cause HSP?

Have you ever heard of HSP?

Children with Henoch-Schonlein purpura (HSP) typically have a purplish rash (purpura), joint pain and swelling (arthritis), and severe stomach pains. They can also have blood in their urine (hematuria).

Palpable purpura in a toddler with HSP, likely after a Mycoplasma pneumoniae infection.
Palpable purpura in a toddler with HSP, likely after a Mycoplasma pneumoniae infection. (CC BY-NC-SA 4.0)

While those can all be very scary symptoms, fortunately, they typically go away without any treatment.

What Causes HSP?

HSP, also known as IgA Vasculitis, is an autoimmune reaction.

“Henoch-Schönlein purpura is caused by an abnormal immune system response in which the body’s immune system attacks the body’s own cells and organs.”

What is Henoch-Schönlein purpura (HSP)?

We don’t know why some kids have this abnormal immune reaction.

We do know that it most commonly occurs after a viral upper respiratory tract infection, although other infections, including chickenpox, measles, and hepatitis, can also trigger HSP.

Do Vaccines Cause HSP?

HSP has been associated with almost anything, from medications and foods, to insect bites and exposure to cold weather, so it is not surprising that some folks would think that vaccines could be a trigger too.

There are even some case reports of children developing HSP after receiving a vaccine. It is important to remember that a case report is basically a gloried anecdote though. It is not the kind of high quality evidence you really want if you are trying to make a case trying to prove causality.

One small study did suggest an increased risk following the MMR vaccine, but it only looked at hospitalized children with HSP. And of 288 hospitalized children with HSP, only eight had received a recent vaccine.

A more robust study, Vaccination and Risk of Childhood IgA Vasculitis, recently found that common childhood vaccines did not significantly increase the risk of HSP.

What to Know About Vaccines and HSP

Since some vaccine-preventable diseases can cause Henoch-Schönlein purpura, there is no evidence that vaccines can cause HSP beyond isolated case reports, and the most recent evidence shows that vaccines do not cause HSP, parents should vaccinate their kids, even if they have had a previous episode of HSP.

More on Vaccines and HSP

Can Vaccines Cause Kawasaki Disease?

Kawasaki disease is rare and there is a good chance that you have never even heard of it, even though the first case was diagnosed in 1961.

Kids with this condition are typically irritable and can develop high fever, swollen glands in their neck, red eyes, red, cracked lips, red, swollen hands and feet, and a rash.

If you have heard of it, there is a good chance it is because anti-vaccine folks are using Kawasaki disease to scare you away from vaccinating and protecting your kids. Lately, talk about Kawasaki disease and the meningococcal B vaccines have been going around.

What Causes Kawasaki Disease?

Kawasaki disease is a type of vasculitis.

Kids who develop Kawasaki disease, who are typically under age 5 years, develop inflammation of their blood vessels, which leads to many of the symptoms and complications we see.

What causes this inflammation?

“Evidence suggests that Kawasaki disease may be linked to a yet-to-be identified infectious agent, such as a virus or bacteria. However, despite intense research, no bacteria, virus, or toxin has been identified as a cause of the disease.”

AAP on Kawasaki disease

We don’t know.

Can Vaccines Cause Kawasaki Disease?

Ask about Kawasaki disease if your child has a fever for five days and other symptoms of Kawasaki disease.
Courtesy of the kdfoundation.org

Because the cause of Kawasaki disease is unknown, that leads some folks to think that it could be vaccines.

Could it?

That vaccine clinical trial data sometimes finds a higher, although not statistically significant risk for Kawasaki disease, gets some of those folks thinking about it even more, except they don’t seem to think about the fact that the risk is never statistically significant.

But aren’t there case reports of kids getting Kawasaki disease after getting a hepatitis A, yellow fever, hepatitis B, or flu vaccine?

Yes, but getting a case report published about one patient who you think got Kawasaki disease soon after getting a vaccine isn’t strong evidence that it wasn’t a coincidence.

“Childhood vaccinations’ studied did not increase the risk of Kawasaki disease; conversely, vaccination was associated with a transient decrease in Kawasaki disease incidence. Verifying and understanding this potential protective effect could yield clues to the underlying etiology of Kawasaki disease.”

Abrams et al. on Childhood vaccines and Kawasaki disease, Vaccine Safety Datalink, 1996-2006.

And not surprisingly, several studies have shown that there isn’t any extra risk for Kawasaki disease after routine vaccines.

One even showed that getting vaccinated could be protective! Another benefit of vaccines and another reason you shouldn’t skip or delay your child’s immunizations.

What to Know About Vaccines and Kawasaki Disease

While anti-vaccine folks often list Kawasaki disease among their vaccine-induced diseases, several studies have shown that vaccines are not associated with Kawasaki disease, except to maybe have a protective effective if you are fully vaccinated.

More on Vaccines and Kawasaki Disease