In several reports, occult bleeding was seen in 50% of the patients with HSP, and 25% of the patients had visible bleeding.7,9,11-13 Endoscopy can be recommended for individuals with suspected HSP because the test may reveal gastrointestinal tract findings that appear without the classic rash.7,9 Renal involvement is common in patients with HSP. Hematuria with or without proteinuria is present in 30% to 70% of patients with HSP. Levy et al14 estimated that HSP nephritis is responsible for 15% of all glomerulopathies in children. A retrospective study by García-Porrúa et al15 noted that hematuria at the onset of HSP with persistence of the renal manifestations during the course of the disease, as well as anemia at disease onset (hemoglobin level <11 g/dL), onset in summer, and relapse, were positive useful predictors for renal sequelae in the adult patients. If a renal biopsy is performed, the percentage of glomeruli showing crescent formation can be correlated with outcome as well. It has been noted that patients with crescents in more than half of the glomeruli are more likely to progress to end-stage or chronic renal disease.16
The erythrocyte sedimentation rate also can be elevated in patients with HSP. Blanco et al17 believed that when comparing adults with children, an elevated erythrocyte sedimentation rate and joint pain more often were found in the adult population, whereas the children had a greater occurrence of abdominal pain, fever, and a preceding upper respiratory tract infection, usually with group A streptococci.
As mentioned previously, HSP easily can be confused with other autoimmune diseases. Thus, the condition should be confirmed with a biopsy specimen from the affected area, which would show leukocytoclastic vasculitis and IgA deposition in the skin or kidney under immunofluorescence microscopy. In many cases, patients with HSP have a history of infection that precedes the symptoms by a few days to 2 weeks. These antecedent infections include streptococcal pharyngitis, viral pharyngitis, sinusitis, urinary tract infection, bronchitis, and diverticulitis.18 Hepatitis B also has been implicated as a cause of HSP.19-21
In a retrospective study comparing the clinical course of patients with HSP who were older than 20 years (adults) with those who were younger than 20 years (children), it was noted that the adults had renal involvement more frequently than the children, with 85% of the adults having a nephropathy versus 25% of the children.17 Of those patients with a nephropathy, the adults developed nephrotic syndrome more often than did the children (13% vs 3%, respectively). Additionally, 13% of the adults with HSP subsequently developed renal insufficiency; however, none of the children with HSP developed this complication. Corticosteroids were given for unresponsive lesions or nephritic involvement. Therapy was required by 63% of the adults and approximately 40% of the children, but 22% of the adults and none of the children needed cytotoxic drugs.17
The overall outcome is favorable in most patients diagnosed with HSP; one study showed a complete recovery in 89% of the adults and 94% of the children with this condition.17 Significant morbidity, however, was seen in a retrospective study of 250 patients aged 15 to 86 years who had enough renal involvement from HSP to require a biopsy. After 15 years, 11% of the patients were dependent on dialysis, and 13% had severe renal failure.22 In rare cases, patients with adult-onset HSP had fatal complications because of arrhythmia from vasculitis, which affected the right atrium, and because of massive pulmonary hemorrhage secondary to extensive petechial bleeding, which was refractory to intravenous steroids.23 Recurrences of HSP tend to be less severe than the original outbreak and usually happen within 4 months of the original symptoms. In children, HSP recurrences have been noted in approximately 33% of patients3,14 and seem to be more likely in the subset of patients with nephritis.3
Most patients do not receive therapy; however, those patients with a higher percentage of crescent formation in the kidneys usually require treatment. Renal transplantation also is an option for patients with HSP with end-stage renal disease, but recurrence is seen after 5 years posttransplantation in 35% of patients.24
In summary, our patient was diagnosed with HSP based on the results of a biopsy, direct immunofluorescence, and laboratory workup. His gastrointestinal tract symptoms are resolved, and he continues to have normal urinalysis results and blood chemistries levels within reference range. He occasionally notes a few new skin lesions and has episodes of mild arthralgia. The patient will continue to be followed up closely to ensure that he does not develop renal abnormalities.