Rheumatological problems in children : when the immune system goes berserk

Rheumatology is a branch of immunology that deals with problems relate to an overactive immune system in the body.  Most of these disorders are idiopathic(no cause known). Risk factors include a genetic predisposition(family history of rheumatological disease) or some mild infection that triggers an exaggerated response from the immune system. A range of rheumatological conditions are known in children that includes arthritis, autoimmune diseases and vasculitis. 

A lot of these conditions are also seen in adults and many children are managed by adult rheumatologists who are usually not well versed with the finer nuances of treating children (they are not children's' doctors after all). Children are not miniature adults and their diseases are different from their adult counterparts. Some of these conditions happen exclusively in children and the adult physicians may have no experience with them. Most of them are much more severe in children and cause much more physical and psycho-social damage in children than in adults. The most important thing is that we have to keep the child’s age in consideration at all times during treatment. Be it dose of the medicines, potential side effects of therapy, maintaining growth and development, bone health, child centered physiotherapy or mental health of the child; all these things need very specialized pediatric training. Hence the need of pediatric rheumatologists and why these patients should be managed by a specialized set of pediatric doctors.

Childhood arthritis

Arthritis refers to swollen joints, pain in the joints and restriction of range of movement at joints. Unlike popular belief, arthritis can happen in children also. The prevalence of childhood arthritis is 1 in 10,000 children; by that estimate, almost a million children may be affected by arthritis in India. They are often misdiagnosed, improperly managed and suffer severe disability by the time they reach a specialist. Most of them undergo unnecessary investigations and sometimes even surgeries (that are absolutely not needed) before they reach us. The etiology of childhood arthritis is varied and can include infections, bleeding disorders, autoimmune disorders, malignancy and the most common form of childhood arthritis i.e. juvenile idiopathic arthritis (JIA). It can start as early as 1 year of age and can also affect other organ systems like eye, skin, heart, lungs, lymph nodes and brain.  There are many sub-classification and types of juvenile arthritis. Each category is unique and needs a detailed history, physical examination, bloods tests, and imaging like radiographs, ultrasonography and MRI to make a diagnosis.

Management includes specialized medicines (dose, monitoring to be done as per child's age and weight), maintaining growth, development and bone health, child centered physiotherapy, nutritional therapy and occupational therapy. Up to 70-90% children have good outcomes if picked up early and given proper management.

 Childhood systemic Autoimmune diseases

Systemic autoimmune diseases involve diseases like childhood lupus, inflammatory myositis etc that involves an overactive immune system and can damage any part of the body. They are usually caused by autoantibodies i.e antibodies targeted against one’s own body organs. Most of these diseases are chronic and need long term medications and follow-ups. 

Systemic Auto immune diseases include

1. Childhood lupus: an autoimmune condition wherein patients can have fever, joint problems, rash, oral ulcers and any organ damage like blood involvement (anemia, low white blood counts, low platelets) damage to kidney, lungs, liver, heart and brain etc. Lupus is much more severe in children than adults and is often missed and underdiagnosed. The diagnosis requires some specialized investigations that are easily available. Treatment includes immunosuppressive medications, sun protection, nutritional rehabilitation etc.

2. Inflammatory myositis includes juvenile dermatomyositis and polymyositis. It involves inflammation in the muscles and skin and can also affect other organs of the body. Patients face difficulty while getting up from bed, climbing stairs, squatting etc. They also present with skin rash, skin ulcers and other organ system involvement like lungs. This condition is again very different from the adult myositis seen by adult rheumatologists and needs a very specialized management. Treatment includes immunosuppressive medications, physiotherapy, nutritional rehabilitation etc.

3.     Scleroderma –This involves skin tightening, vasculopathy causing skin ulcers, bluish discoloration of fingers in cold, gastric problems, lung disease etc. It also can also be managed by medications.

4.     Neonatal Lupus – This condition arises when auto-antibodies are passed on from the mother’s blood to the unborn child in utero through the placenta. This can cause heart disease in the fetus that can be lethal. In less severe form of the disease child can be born with rashes, blood problems, liver diseases etc. Most of the times, mothers are completely asymptomatic and the autoimmunity in mother is detected only when the child is detected to have neonatal lupus. This disease is also fairly preventable and treatable if picked up early.

5.     Antiphospholipid Antibody syndrome – The autoantibodies produced in this disease can cause thrombosis in any artery or vein of the body causing gangrene of the limbs, intestine, vessels of the lungs and even brain stroke.

Childhood Vasculitis : 

The term ‘vasculitis’ refers to swelling of blood vessels in the body. This condition can happen when the immune system attacks the blood vessels. A spectrum of vasculitis is known in childhood:

1. Kawasaki Disease(KD) – This is the most common form of childhood vasculitis. This is most commonly seen in children less than five years of age . Children develop long term fever (unresponsive to antibiotics), rash, redness of lips and tongue, swollen lymph nodes, skin peeling in hands and feet and excessive irritability. If not detected and treated within first week, this illness can result in severe heart problems including dilation of coronary arteries. This can cause thrombosis and early heart attacks or myocardial infarction. Since most of the symptoms of KD resemble any other childhood infection, it is frequently missed by physicians and children eventually end up with heart disease that can cause significant cardiovascular problems in their future. It is very important to pick up these symptoms early and treat as soon as possible so that major heart related complications can be avoided.

2. Post COVID  Multi System Inflammatory Syndrome in Children associated with COVID -19 (MIS-C ) – Over the last few years, we have been seeing a lot of children having prolong fever and multisystem disease resulting from the after-effects of past COVID-19 infections. This can affect heart and coronary arteries with symptoms similar to those of Kawasaki disease. This may also have long implications as once the heart gets affected, the children may remain at risk of long standing cardiovascular complications.

3. Ig A Vasculitis/ Henosch Schonlein Purpura

This is also a fairly common childhood vasculitis. Children present with crops of red rash over their lower limbs and buttocks along with joint pains and pain abdomen. It can also have other organ involvement. Correct diagnosis and management can prevent complications associated with this disease.

 4. Some other forms of vasculitis which are not very common in children include Polyarteritis nodosa, Takayasu aorto-arteritis and ANCA vasculitis

 Other inflammatory conditions:

Uveitis and Neuro-retinitis: This refers to inflammation in the eye that may be in the form of uveitis  or neuro-retinitis. These can be caused by a spectrum of diseases and need very specialized treatment. If not treated in time, these conditions can even cause blindness. These diseases are co-managed by ophthalmologists and pediatric rheumatologists.

Autoinflammatory syndromes: These include recurrent fever syndromes that may present with recurrent fever episodes along with rash, body swelling, joint problems, chest and abdominal pain, kidney and eye problems. Most physicians are unaware of such conditions and it needs a very careful history and specialized tests to make these diagnoses. Many patients suffer for years before they are diagnosed.