FlightBridgeED

The ABCs of HSP

HSP 

 Henoch-Schonlein Purpura (HSP), pronounced [HEH-nok SHOON-line PURR-pyuh-ruh], is the most common type of vasculitis found in children. It can be found in adults as well, but most often, you will see this presentation in the pediatric population. It is characterized by the deposition of immunoglobulin A (IgA) complexes within the walls of small vessels. Most cases occur in children less than ten years of age, with a median age of around six years old. It does tend to occur more often during the winter months, and the incidence seems to be equal among both sexes.

Pathophysiology 

The majority of children presenting with HSP have recently had an upper respiratory tract infection (URI), which suggests a possible infectious trigger. There have also been reported cases occurring after receiving vaccines. As noted above, the pathologic feature of HSP is the deposition of IgA-containing complexes in the small vessel walls of affected organs, including the kidneys. IgA is in our serum and mucosal secretions. It is the largest class of immunoglobulins and plays a significant role in mucosal immunity. When these complexes are deposited, they activate the alternative complement pathways. This activation recruits inflammatory mediators, which is what leads to the clinical manifestations seen with HSP.

Clinical Findings

HSP is a systemic vasculitis, so there is involvement in many organs. There is a “classic” tetrad (meaning group of four) involved which includes: 

  • Palpable purpura
  • Arthralgia
  • Abdominal pain
  • Renal disease

All children with HSP will present with skin involvement. This involvement is most commonly petechia and palpable purpura. The purpura tends to be symmetrically distributed over the lower legs, buttocks, and forearms as the most common areas of involvement. The rash is non-blanching and not pruritic. 

HSP

Image by Mnokel at Arabic Wikipedia - https://commons.wikimedia.org/w/index.php?curid=5678808

Three out of four children with HSP will present with some form of arthritis/arthralgia as well. Joints most commonly involved are the hips, knees, and ankles. There may be associated swelling and tenderness around the joint. The child may present with a refusal to bear weight. The joint is typically not red and does not involve an effusion of the area. Joint involvement is a transient finding, with no long-term complications or chronic damage to the affected joints.

A large majority of children will also complain of diffuse, colicky, abdominal pain with HSP. Abdominal pain tends to be worse after eating and is sometimes associated with nausea, vomiting, and diarrhea. These symptoms are due to the inflammation within the bowel wall. Renal involvement is common but not always present. It is most often manifested as microscopic hematuria that usually develops within four weeks of the onset of HSP. Proteinuria can also be present. Renal function usually remains within normal limits.

Diagnosis

The diagnosis of HSP can typically occur at the bedside after a thorough evaluation based on the typical clinical findings mentioned above. Laboratory testing is not necessary but helps assess possible renal involvement through the use of a urinalysis or serum creatinine. A urinalysis can indicate the presence of blood (hematuria) or protein (proteinuria), both of which can be indicators for nephritis. Imaging studies may be necessary for further evaluation of abdominal pain if that is a concern.

Management

HSP is typically a self-limiting illness with the focus of treatment being primarily supportive. Treatment consists of ensuring adequate hydration, treating pain, and monitoring for potential complications. Hydration can usually be maintained through oral fluids, but if the child is having trouble with this, intravenous hydration may be needed. Pain is most often relieved with the use of NSAIDs. The use of corticosteroids in HSP continues to be controversial and has been for a long while now. Overall, the quality of evidence continues to be inadequate to support the use of corticosteroids. In the uncommon situation where severe kidney involvement occurs, you may see the use of immunosuppressive treatment. However, mild renal involvement, such as microscopic hematuria or mild proteinuria, should not be treated with immunosuppressive medications. The majority of patients with HSP will improve spontaneously.  

Prognosis and Conclusion

Although HSP can be a serious disease, it is not a very commonly encountered situation. As mentioned above, the outcome for the majority of children with HSP is excellent with the spontaneous resolution of their symptoms. HSP can recur in patients and has an approximate recurrence rate of 30% and typically occurs within the first six months of initial presentation. Subsequent episodes tend to be milder in presentation and the duration shorter. 

Again, HSP is a common childhood vasculitis often encountered in the pre-hospital and ED settings. While generally mild with few complications, it can be scary looking in appearance, especially for the child’s parents. Being familiar with the presentation and potential treatment can help in providing positive reassurance to the patient and parents in this situation.

References

Tintinalli, J. E. (2020). Tintinalli’s emergency medicine(9thed.). McGraw Hill.

Trnka, P. (2013). Henoch-Schonlein purpura in children. Journal of Paediatrics and Child Health, 49, 995-1003. https://doi:10.1111/jpc.12403

By accepting you will be accessing a service provided by a third-party external to https://flightbridgeed.com/

Please publish modules in offcanvas position.

FlightBridgeED Logo

One acccount to unlock a universe of discovery

FlightBridgeED® FAST Symposium™ EMerge™

Don't have an account yet? Register Now!

Sign in to your account