IgA Vasculitis (Henoch-Schonlein Purpura)

CD Lee et al. NEJM 2022; 387: 833-838. Telescoping the Diagnostic Process

This clinical problem-solving case:  “3-year-old boy was brought to the hospital with a 4-day history of vomiting and abdominal pain in the left lower quadrant. He had associated chills without fever, nonbloody and nonbilious emesis, constipation, reduced urinary output, and a decreased activity level.” He developed a rash more than 5 days after presentation.

This turns out to be a good review of IgA Vasculitis (HSP).

A few excerpts:

IgA vasculitis is the most common vasculitis of childhood.1 The disease is classified as a small-vessel vasculitis and most commonly affects White and Asian children, with a slight male predominance. It results from the deposition of IgA immune complexes in involved organ systems and is preceded by infection in most patients.2 This is perhaps unsurprising given the primary function of IgA in mucosal immunity. The most commonly implicated organism is group A β-hemolytic streptococcus.1

IgA vasculitis primarily involves the skin, gastrointestinal tract, joints, and kidneys, with involvement in 95%, 70%, 70 to 90%, and 40 to 50% of cases, respectively, in case series3; other data suggest that kidney involvement is even more common, with microhematuria present in the majority of patients.4 Less common manifestations include orchitis (in 14% of male patients) and, in rare cases, central nervous system involvement.3 Skin involvement is almost universal; a petechial or purpuric rash in dependent areas (typically the buttocks and lower legs) is the classic manifestation, but other skin manifestations, including bullae, edema, and necrosis, can be seen.1,3 

IgA vasculitis affecting the gastrointestinal tract can manifest as upper or lower gastrointestinal bleeding. Bowel edema can create a lead point, causing intussusception in up to 3% of patients, as occurred in our patient.1 …In the majority of cases, the rash precedes the onset of gastrointestinal symptoms; our patient was among the minority (approximately 25%) of patients in whom this order is reversed.5 Rare gastrointestinal complications include bowel infarction, perforation, strictures, and protein-losing enteropathy.2,5

Related blog post: Henoch-Schonlein Purpura and Neurologic Manifestations

Non-blanching petechiae