Henoch-Schönlein Purpura Is Difficult to Define

The diagnosis of Henoch-Schönlein purpura requires a small-vessel biopsy to confirm the presence of IgA, Dr. Thomas G. Cropley said at the 21st World Congress of Dermatology in Buenos Aires.

IgA deposits in vessel walls along with prominent extracutaneous manifestations are the hallmarks of Henoch-Schönlein purpura, a specific type of small-size vessel vasculitis that is the most common vasculitis syndrome in children, often occurring after a respiratory tract infection.

In recent years three different sets of classification criteria have been proposed, the oldest of which does not list IgA deposition among its diagnostic criteria. In 1990, the American College of Rheumatology published its Classification of Henoch-Schönlein purpura (Arthritis Rheum. 1990;33:1114–21), which requires four diagnostic criteria:

▸ Palpable purpura, defined as raised “palpable” hemorrhagic skin lesions not related to thrombocytopenia;

▸ Age less than 20 years at disease onset;

▸ Bowel angina, or diffuse abdominal pain, which might include bloody diarrhea;

▸ Presence of granulocytes in vessel walls.

“Notice that there is no mention of immunofluorescence or IgA here,” said Dr. Cropley. The ACR definition is based only on histopathology and clinical symptoms. Dermatologists were not involved in developing the classification system, which has since been criticized for the “rather obvious lack of dermatological insight,” said Dr. Cropley, professor of medicine in the division of dermatology at the University of Massachusetts, Worcester.

A group of rheumatologists, nephrologists, and pulmonologists convened in Chapel Hill, N.C., in 1994 and developed consensus guidelines for the diagnosis of various forms of vasculitis, including Henoch-Schönlein purpura (Arthritis Rheum. 1994;37:187–92). “The Chapel Hill definition of Henoch-Schönlein purpura requires the presence of vasculitis with IgA-dominant immune deposits affecting small vessels, which they defined as capillaries, venules, or arterioles,” said Dr. Cropley. The definition noted the vasculitis typically involves skin, gut, and glomeruli and is associated with arthralgias or arthritis. “IgA is part of the definition, but there are still many other areas of 'looseness' in this definition.”

In 2006 the European League Against Rheumatism (EULAR) and the Pediatric Rheumatology Society published Classification Criteria for Henoch-Schönlein purpura (Ann. Rheum. Dis. 2006;65:936–41). In their version, palpable purpura is a mandatory criterion and at least one of the following must be present: diffuse abdominal pain; biopsy-proved predominant IgA deposition; acute arthritis in any joint or arthralgia; and renal involvement (hematuria and/or proteinuria).

The epidemiology of Henoch-Schönlein purpura is well described. In the United States, the incidence is about 10 cases per 10,000. The majority of cases (about 75%) begin in childhood, with an equal prevalence in males and females. The disease is often preceded by a respiratory tract infection, but no typical or unique pathogen has been associated with the disease, said Dr. Cropley. Prevalence is highest in the autumn and winter, when respiratory tract infections are more common.

Adult cases are less likely to be associated with an antecedent infection. The prevalence of adult-onset is higher in men than in women. “There is anecdotal evidence suggesting that there may be an increased association with malignancy in adult cases,” said Dr. Cropley.

Differential diagnosis of Henoch-Schönlein purpura includes other forms of small-size vessel vasculitis causing palpable purpura, such as IgG leukocytoclastic vasculitis, Wegener's granulomatosis, and microscopic polyangiitis. Other IgA-associated vasculitides should also be considered, including IgA rheumatoid factor-associated small-vessel vasculitis and acute hemorrhagic edema of infancy.

Whether the presence of IgA predicts an increased risk of renal involvement is unknown. An extensive epidemiologic study of Henoch-Schönlein purpura showed renal involvement in one-third of children (Kidney Int. 1998;53:1755–9). Significant independent risk factors for chronic renal disease were severe abdominal symptoms, prolonged purpura, and decreased factor XIII activity. The prognostic significance of IgA status was not evaluated, because the study used the 1990 ACR diagnostic criteria.

IgA deposition is a defining criterion of Henoch-Schönlein purpura in the two most recent diagnostic guidelines. Henoch-Schönlein purpura patients may have a poorer renal prognosis than patients with other forms of small-vessel vasculitis. For these reasons, Dr. Cropley recommends a biopsy for immunofluorescence and histopathology, if possible, in patients who appear to have Henoch-Schönlein purpura. Serum IgA levels have been correlated with the risk of IgA nephropathy in adults with Henoch-Schönlein purpura; thus, monitoring serum IgA level over time may help identify patients at risk of chronic renal disease.

Dr. Cropley reported no conflicts of interest.

Even in the presence of palpable lesions, vessel biopsy is required to diagnose Henoch-Schönlein purpura. COURTESY DR. LAUREN ALBERTA-WSZOLEK

The diagnosis of Henoch-Schönlein purpura requires a small-vessel biopsy to confirm the presence of IgA, Dr. Thomas G. Cropley said at the 21st World Congress of Dermatology in Buenos Aires.

IgA deposits in vessel walls along with prominent extracutaneous manifestations are the hallmarks of Henoch-Schönlein purpura, a specific type of small-size vessel vasculitis that is the most common vasculitis syndrome in children, often occurring after a respiratory tract infection.

In recent years three different sets of classification criteria have been proposed, the oldest of which does not list IgA deposition among its diagnostic criteria. In 1990, the American College of Rheumatology published its Classification of Henoch-Schönlein purpura (Arthritis Rheum. 1990;33:1114–21), which requires four diagnostic criteria:

▸ Palpable purpura, defined as raised “palpable” hemorrhagic skin lesions not related to thrombocytopenia;

▸ Age less than 20 years at disease onset;

▸ Bowel angina, or diffuse abdominal pain, which might include bloody diarrhea;

▸ Presence of granulocytes in vessel walls.

“Notice that there is no mention of immunofluorescence or IgA here,” said Dr. Cropley. The ACR definition is based only on histopathology and clinical symptoms. Dermatologists were not involved in developing the classification system, which has since been criticized for the “rather obvious lack of dermatological insight,” said Dr. Cropley, professor of medicine in the division of dermatology at the University of Massachusetts, Worcester.

A group of rheumatologists, nephrologists, and pulmonologists convened in Chapel Hill, N.C., in 1994 and developed consensus guidelines for the diagnosis of various forms of vasculitis, including Henoch-Schönlein purpura (Arthritis Rheum. 1994;37:187–92). “The Chapel Hill definition of Henoch-Schönlein purpura requires the presence of vasculitis with IgA-dominant immune deposits affecting small vessels, which they defined as capillaries, venules, or arterioles,” said Dr. Cropley. The definition noted the vasculitis typically involves skin, gut, and glomeruli and is associated with arthralgias or arthritis. “IgA is part of the definition, but there are still many other areas of 'looseness' in this definition.”

In 2006 the European League Against Rheumatism (EULAR) and the Pediatric Rheumatology Society published Classification Criteria for Henoch-Schönlein purpura (Ann. Rheum. Dis. 2006;65:936–41). In their version, palpable purpura is a mandatory criterion and at least one of the following must be present: diffuse abdominal pain; biopsy-proved predominant IgA deposition; acute arthritis in any joint or arthralgia; and renal involvement (hematuria and/or proteinuria).

The epidemiology of Henoch-Schönlein purpura is well described. In the United States, the incidence is about 10 cases per 10,000. The majority of cases (about 75%) begin in childhood, with an equal prevalence in males and females. The disease is often preceded by a respiratory tract infection, but no typical or unique pathogen has been associated with the disease, said Dr. Cropley. Prevalence is highest in the autumn and winter, when respiratory tract infections are more common.

Adult cases are less likely to be associated with an antecedent infection. The prevalence of adult-onset is higher in men than in women. “There is anecdotal evidence suggesting that there may be an increased association with malignancy in adult cases,” said Dr. Cropley.

Differential diagnosis of Henoch-Schönlein purpura includes other forms of small-size vessel vasculitis causing palpable purpura, such as IgG leukocytoclastic vasculitis, Wegener's granulomatosis, and microscopic polyangiitis. Other IgA-associated vasculitides should also be considered, including IgA rheumatoid factor-associated small-vessel vasculitis and acute hemorrhagic edema of infancy.

Whether the presence of IgA predicts an increased risk of renal involvement is unknown. An extensive epidemiologic study of Henoch-Schönlein purpura showed renal involvement in one-third of children (Kidney Int. 1998;53:1755–9). Significant independent risk factors for chronic renal disease were severe abdominal symptoms, prolonged purpura, and decreased factor XIII activity. The prognostic significance of IgA status was not evaluated, because the study used the 1990 ACR diagnostic criteria.

IgA deposition is a defining criterion of Henoch-Schönlein purpura in the two most recent diagnostic guidelines. Henoch-Schönlein purpura patients may have a poorer renal prognosis than patients with other forms of small-vessel vasculitis. For these reasons, Dr. Cropley recommends a biopsy for immunofluorescence and histopathology, if possible, in patients who appear to have Henoch-Schönlein purpura. Serum IgA levels have been correlated with the risk of IgA nephropathy in adults with Henoch-Schönlein purpura; thus, monitoring serum IgA level over time may help identify patients at risk of chronic renal disease.

Dr. Cropley reported no conflicts of interest.

Even in the presence of palpable lesions, vessel biopsy is required to diagnose Henoch-Schönlein purpura. COURTESY DR. LAUREN ALBERTA-WSZOLEK

The diagnosis of Henoch-Schönlein purpura requires a small-vessel biopsy to confirm the presence of IgA, Dr. Thomas G. Cropley said at the 21st World Congress of Dermatology in Buenos Aires.

IgA deposits in vessel walls along with prominent extracutaneous manifestations are the hallmarks of Henoch-Schönlein purpura, a specific type of small-size vessel vasculitis that is the most common vasculitis syndrome in children, often occurring after a respiratory tract infection.

In recent years three different sets of classification criteria have been proposed, the oldest of which does not list IgA deposition among its diagnostic criteria. In 1990, the American College of Rheumatology published its Classification of Henoch-Schönlein purpura (Arthritis Rheum. 1990;33:1114–21), which requires four diagnostic criteria:

▸ Palpable purpura, defined as raised “palpable” hemorrhagic skin lesions not related to thrombocytopenia;

▸ Age less than 20 years at disease onset;

▸ Bowel angina, or diffuse abdominal pain, which might include bloody diarrhea;

▸ Presence of granulocytes in vessel walls.

“Notice that there is no mention of immunofluorescence or IgA here,” said Dr. Cropley. The ACR definition is based only on histopathology and clinical symptoms. Dermatologists were not involved in developing the classification system, which has since been criticized for the “rather obvious lack of dermatological insight,” said Dr. Cropley, professor of medicine in the division of dermatology at the University of Massachusetts, Worcester.

A group of rheumatologists, nephrologists, and pulmonologists convened in Chapel Hill, N.C., in 1994 and developed consensus guidelines for the diagnosis of various forms of vasculitis, including Henoch-Schönlein purpura (Arthritis Rheum. 1994;37:187–92). “The Chapel Hill definition of Henoch-Schönlein purpura requires the presence of vasculitis with IgA-dominant immune deposits affecting small vessels, which they defined as capillaries, venules, or arterioles,” said Dr. Cropley. The definition noted the vasculitis typically involves skin, gut, and glomeruli and is associated with arthralgias or arthritis. “IgA is part of the definition, but there are still many other areas of 'looseness' in this definition.”

In 2006 the European League Against Rheumatism (EULAR) and the Pediatric Rheumatology Society published Classification Criteria for Henoch-Schönlein purpura (Ann. Rheum. Dis. 2006;65:936–41). In their version, palpable purpura is a mandatory criterion and at least one of the following must be present: diffuse abdominal pain; biopsy-proved predominant IgA deposition; acute arthritis in any joint or arthralgia; and renal involvement (hematuria and/or proteinuria).

The epidemiology of Henoch-Schönlein purpura is well described. In the United States, the incidence is about 10 cases per 10,000. The majority of cases (about 75%) begin in childhood, with an equal prevalence in males and females. The disease is often preceded by a respiratory tract infection, but no typical or unique pathogen has been associated with the disease, said Dr. Cropley. Prevalence is highest in the autumn and winter, when respiratory tract infections are more common.

Adult cases are less likely to be associated with an antecedent infection. The prevalence of adult-onset is higher in men than in women. “There is anecdotal evidence suggesting that there may be an increased association with malignancy in adult cases,” said Dr. Cropley.

Differential diagnosis of Henoch-Schönlein purpura includes other forms of small-size vessel vasculitis causing palpable purpura, such as IgG leukocytoclastic vasculitis, Wegener's granulomatosis, and microscopic polyangiitis. Other IgA-associated vasculitides should also be considered, including IgA rheumatoid factor-associated small-vessel vasculitis and acute hemorrhagic edema of infancy.

Whether the presence of IgA predicts an increased risk of renal involvement is unknown. An extensive epidemiologic study of Henoch-Schönlein purpura showed renal involvement in one-third of children (Kidney Int. 1998;53:1755–9). Significant independent risk factors for chronic renal disease were severe abdominal symptoms, prolonged purpura, and decreased factor XIII activity. The prognostic significance of IgA status was not evaluated, because the study used the 1990 ACR diagnostic criteria.

IgA deposition is a defining criterion of Henoch-Schönlein purpura in the two most recent diagnostic guidelines. Henoch-Schönlein purpura patients may have a poorer renal prognosis than patients with other forms of small-vessel vasculitis. For these reasons, Dr. Cropley recommends a biopsy for immunofluorescence and histopathology, if possible, in patients who appear to have Henoch-Schönlein purpura. Serum IgA levels have been correlated with the risk of IgA nephropathy in adults with Henoch-Schönlein purpura; thus, monitoring serum IgA level over time may help identify patients at risk of chronic renal disease.

Dr. Cropley reported no conflicts of interest.

Even in the presence of palpable lesions, vessel biopsy is required to diagnose Henoch-Schönlein purpura. COURTESY DR. LAUREN ALBERTA-WSZOLEK