Two experts share four things scientists now know about autoimmune diseases in kids, including the latest understanding and research
BY JESSICA BROWN
When you think of some of the common symptoms of autoimmune diseases – like joint pain, swelling and stiffness, and thick, scaly skin – you probably picture an adult struggling with these kinds of health problems.
But children can also be affected by autoimmune conditions, such as pediatric plaque psoriasis, a chronic skin disease characterised by red, scaly skin; juvenile idiopathic arthritis (JIA), a group of disorders characterized by arthritis persisting for at least six weeks before the age of 16; and pediatric active psoriatic arthritis (PsA), a subtype of JIA characterized by joint inflammation and skin lesions that resembles adult PsA.
Scientists still have much to learn about what causes autoimmune diseases, which occur when the immune system attacks healthy tissue in various parts of the body, often resulting in chronic inflammation. But they also have made many critical discoveries over the past several years that are helping children who have autoimmune diseases.
For Autoimmune Disease Awareness Month, we interviewed two researchers who study juvenile autoimmune diseases to learn more about what strides have been made in better understanding the diseases – and what treatment options could mean for these young patients.
- Genetics play a role, but there are also other factors
While the exact cause of many of these conditions is unknown, scientists have made significant progress in understanding what may trigger the immune system to attack its own healthy tissues. Many genes involved in autoimmune diseases have been identified over the past decade, and studies have revealed potential environmental causes too.
“We know that a trauma to the body, such as slamming a finger in a car door, can trigger a condition like arthritis in some susceptible children,” says Anne Stevens, M.D., Ph.D., Senior Director of Translational Medicine, Janssen Pharmaceutical Companies of Johnson & Johnson. “For whatever reason, the normal inflammation that occurs when the body is repairing the injury doesn’t turn off and becomes chronic.”
Certain infections can have the same effect. For example, a well-documented example is Streptococcus infections, which are fairly common in children and can cause diseases such as strep throat, scarlet fever, rheumatic fever and impetigo, a bacterial skin infection.
“Some kids who get strep infection, for example, subsequently develop a type of psoriasis called guttate psoriasis,” says Lloyd Miller, M.D., Ph.D., Vice President of Immunodermatology, Janssen. “Guttate psoriasis disappears in some children, but others can go on to develop chronic plaque psoriasis, which can be a lifelong condition.”
- Early recognition, diagnosis and treatment are crucial
Prompt diagnosis is key to successfully managing autoimmune diseases, explains Dr Stevens.
“JIA, for example, can dramatically affect a child’s growth and bone development,” she explains. “It’s one of the reasons we treat this disease so aggressively—to enable kids to catch up to their peers in height.”
Undertreated or uncontrolled forms of pediatric arthritis can also interfere with the development of a child’s fine motor skills and limit mobility, adds Dr Stevens. And because these conditions can lead to bone loss over time, inadequate treatment in children can result in the need for more invasive interventions in adulthood.
Even if only a mild amount of inflammation remains in a child’s body, it can still cause damage to the point that these patients may end up needing joint replacement surgery in their 20s or 30s.
“Even if only a mild amount of inflammation remains in a child’s body, it can still cause damage to the point that these patients may end up needing joint
Replacement surgery in their 20s or 30s,” she explains. “Fortunately, the use of ultrasound technology has made it easier to detect very mild inflammation, so we’re able to make prompt changes to a child’s treatment plan if we find evidence of it.”
Keeping kids with autoimmune diseases in remission may also improve their well-being. When people are in remission, they have fewer or no symptoms, which can make it easier for children to fit in with their peers and feel like a regular kid.
“Children who have joint pain from certain types of JIA such as pediatric active PsA, for example, may find it hard to participate in class and miss school due to their symptoms,” Dr Stevens says.
“And if their pain is severe, they might struggle to write and draw because they can’t hold a pencil.”
Kids’ ability to make friends and socialise can also be impacted. Children with psoriasis or active PsA, who have patches of plaques on their skin, often want to hide their skin or cover up their plaques during certain activities, such as swimming. Their peers may ask them many questions related to their condition, particularly if their plaques are in noticeable spots, like the face and scalp.
“Many children don’t understand a condition like psoriasis, which can lead to teasing and the social exclusion of kids who have it,” Dr Miller says.
“This can cause their condition to flare, as well as increase the likelihood of developing mental health disorders, such as depression and anxiety. So, there’s a real urgency in treating children early because it can make a marked difference in their quality of life.”
- Untreated autoimmune conditions may raise the risk of other serious diseases
Understanding conditions like certain types of JIA such as pediatric active PsA is vital is because the chronic inflammation associated with them can cause widespread damage to the body over time.
In recent years, researchers have learned that inflammation plays a central role in many diseases, such as heart disease, diabetes mellitus, certain types of cancer and neurodegenerative disorders. So, the presence of chronic inflammation in kids with autoimmune disorders may make them more vulnerable to a host of other serious illnesses.
“There’s a perception that a condition like psoriasis is mainly cosmetic,” Dr Miller says. “But a child who has it may also develop obesity, high cholesterol, high blood pressure, and/or inflammatory bowel disease.
“These comorbidities are likely due to the chronic inflammation associated with these conditions having effects throughout the body, as well as the fact that often active PsA patients don’t get enough exercise, since the joint pain, swelling and stiffness often limits their ability to be physically active.
Autoimmune diseases can also be associated with uveitis, a type of eye inflammation that occurs when the middle layer of the eyeball (the uvea) becomes swollen and red. The symptoms of uveitis in children are not always as obvious as they are in adults, which can cause a delay in diagnosis, which is dangerous in patients of any age.
“Uveitis is a major cause of blindness in children, so it’s crucial to catch it early and treat it before damage to the eye begins to occur,” Dr Stevens says.
- Children with autoimmune diseases have treatment options
For children with milder forms of these conditions, treatment options are available. For example, joint symptoms can be managed in the short term with corticosteroids or nonsteroidal anti-inflammatory medications, such as ibuprofen.
With these conditions, the space between the bones in the joint narrows, causing the bones to fuse together. Once that happens, a child may lose function in the affected joint. So there has been a real need for treatments that can stop the progression of further joint damage.
But for kids with moderate to severe psoriasis and certain types of JIA, such as pediatric active PsA, who require different treatment, medications have been more limited until recently, as more options have become available.
Having options for treating children with JIA is particularly helpful, says Dr Stevens, because some types of JIA can affect five or more joints, causing significant impairment.
“With these conditions, the space between the bones in the joint narrows, causing the bones to fuse together,” Dr Stevens explains.
“Once that happens, a child may lose function in the affected joint. So there has been a real need for treatments that can stop the progression of further joint damage.”
These treatments, Dr Miller explains, may help to decrease the risk of comorbidities, like heart disease and diabetes mellitus, which are also lifelong conditions. “They’ve helped advance how we treat children with autoimmune diseases.” — The Health
This article appeared in Johnson & Johnson’s website in March