Adapted from CPC presentation by Molly Graham, November 11th, 2016
Differential Diagnosis for joint pain in a pediatric patient
HSP is the most common systemic vasculitis seen in children, and is characterized by palpable purpura without thrombocytopenia or coagulopathy, as well as abdominal pain, joint pains, proteinuria or hematuria. To diagnose HSP, a patient must have palpable purpura with a predominance of the lower extremities, and one additional symptom or finding on physical exam. Diffuse abdominal pain is commonly the first symptom and may include the testicles in males, but other gastrointestinal symptoms such as nausea and vomiting may be the first sign of disease, followed by skin findings. Patients with severe abdominal pain should be evaluated with an abdominal ultrasound to evaluate for intussuception or peritoneal fluid.
HSP symptoms are due to IgA deposits, while the trigger is still unknown, These deposits may be associated with a recent URI, group A strep infection, cold weather, or insect bites. Glomerular inflammation is typically self-limited, but in rare cases can lead to life-long renal disease. Additional complications of HSP include neurologic symptoms (headaches, seizures) and intussusception secondary to intestinal wall inflammation. Most patients (90%) are under the age of 17, and present in the fall or winter.
Diagnosis of HSP is typically clinical, however a skin biopsy of a lesion can be taken to identify leukocytoclastic vasculitis. Treatment includes NSAIDs for pain control,