Researchers found that two-thirds of children with rare autoimmune diseases experienced some additional symptoms, which were not formally associated with antiphospholipid syndrome (APS).

The research was published in the journal, Pediatric Rheumntiphosatology. Apholipid syndrome (APS) is rare in children and known to cause inflammation and recurring, potentially fatal blood clots.

Each year, around two of every 100,000 adults received a new diagnosis of APS. The number of children with APS is likely much smaller but unknown---and for kids with the disease, it's often not identified until destructive clotting has already occurred. The research has reviewed hundreds of potential cases from the last 20 years, which only amounted to 21 children with a definite diagnosis.

They found that two-thirds of the children experienced additional symptoms such as low platelet counts, hemolytic anaemia and livedo reticularis, a rash indicating abnormal blood flow to the skin. "Beyond clots, there is not one definitive feature of this rare disease in children, rather, there is a constellation of symptoms we found among these patients," said Jacqueline Madison, M.D., lead author of the paper and a rheumatologist at the University of Michigan Health.

She further added, "If we can prove these symptoms are related to the condition, then physicians should be able to test for APS sooner and diagnose the disease earlier to prevent potentially catastrophic clots." Nearly half of the children suffered recurrent blood clots, many of them not taking full-dose anti-coagulants. Researchers have believed this might have occurred because the patients were either not adhering to treatment or were only prescribed smaller, preventative doses.

"We found that some children with APS develop significant damage to their bodies from the disease over time, too, and it will be important to try to prevent that damage going forward," Madison said. Almost half of the patients were first diagnosed with lupus, another autoimmune disease where the body attacks its own immune system, before receiving an APS diagnosis.

Lupus is a lot more common among children than APS, Madison said, and rheumatologists need to be educated to test for antiphospholipid syndrome after making a lupus diagnosis. "These findings underscore the importance of creating pediatric-specific criteria for the diagnosis of APS," said Madison, who is also an assistant professor of rheumatology at the University of Michigan Medical School.

"We have already started a prospective study of this young patient population to better understand how the disease presents in the earliest stages and to try to find even better diagnostic markers in the blood. These are major steps towards limiting blood clots and potential hospitalisations or deaths due to APS in kids," she concluded.