LAS VEGAS – IgA vasculitis has a reputation as an illness of childhood, but rheumatologist Alexandra Villa-Forte, MD, MPH, cautioned colleagues that it can strike adults, too, often in a much more severe form. And, she warned, it’s likely not as rare as physicians assume.

Henoch Schonlein purpura on the lower extremities in a 9-year-old boy Catalina Matiz, MD

Henoch Schonlein purpura on the lower extremities in a 9-year-old boy

“I believe it’s more common in adults than reported. There’s a huge problem with establishing the right way to make the diagnosis in adults, which is why it is missed,” said Dr. Villa-Forte of the Cleveland Clinic, who spoke at the annual Perspectives in Rheumatic Diseases held by Global Academy for Medical Education.

But even if IgA vasculitis (IV) is diagnosed correctly in adults, there are many questions about how to move forward, she said. “Treatment in adults remains a problem since we don’t have data.”

IV is also known as Henoch-Schönlein purpura, or HSP, and “spring fever” because it often appears in children in the spring following an upper respiratory infection.

The condition causes vasculitis, the swelling of small blood vessels in organs such as the skin, joints, kidneys, and intestines. Leaking blood vessels can cause skin rashes known as purpura.

The estimated ranges of disease are high, with the annual incidence in children estimated at 3-26 per 100,000 and in adults at 0.1-1.8 per 100,000. Dr. Villa-Forte noted that the male-to-female ratio is 1.5, and she said the condition is less common in African Americans.

“In children, this is a disease that is frequently self-limited. Most of them don’t need treatment, and most of them do not relapse,” Dr. Villa-Forte said. “In adults, it’s more resistant to treatment, frequently chronic, and frequently relapsing over the years.”

There are other differences in IV between children and adults. “In children, there is a clear seasonal pattern of disease that is not seen in adults,” she said, and it’s linked to preceding infections.

“In adults, there are multiple causes, and most of the time they’re not identified,” she said.

As for diagnosis, she suggests looking at clinical presentation and whether tissue biopsy shows cutaneous leukocytoclastic vasculitis with IgA deposits. She cautioned that increased serum IgA is seen in about 50% of adult patients, making it an unreliable indicator.

Prognosis is much better for children than adults. According to a 2014 study, 80% of children completely recover, compared with 40% of adults. Persistent hematuria or proteinuria occurs in 30% of children and 60% of adults, respectively, while chronic renal failure occurs in 2% of children and 10% of adults (J Korean Med Sci. 2014 Feb;29[2]:198-203).

It’s possible that the latter number may be higher, with as many as 30% of adults developing chronic kidney disease (CKD), Dr. Villa-Forte said.

An estimated 97% of nephritis develops within the first 6 months of disease onset in adults, she said, “and in adults, the active renal disease can persist for over 20 years.”

Guidelines suggest that patients be monitored for CKD for 6 months after disease onset, but Dr. Villa-Forte said it’s better to monitor them for 12 months.

What about treatment? “The major challenge in adults is the real absence between correlation between initial presentation and long-term renal outcome,” she said. “That makes for a difficult choice in terms of treatment selection.”

Fever and cutaneous lesions above the waist may predict renal involvement, she said, although that isn’t confirmed, and increasing proteinuria is a probable factor predicting progression/complications.

According to Dr. Villa-Forte, the value of early treatment hasn’t been proved. Due to the risk of kidney problems, she said, “we don’t feel like we can just watch patients – that we need to do something. But there’s not good data supporting that.”

Various protocols involving steroids, early plasmapheresis, rituximab (Rituxan), and other drug regimens lack evidence, she said, although use of steroids in early nephritis may be beneficial in adults.

Dr. Villa-Forte had no relevant disclosures.

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