What is Adult Onset Still's Disease or AOSD?
Adult Onset Still's disease (AOSD) is an uncommon type of inflammatory disease, which causes high fevers, pain in the joints and rash in patients. Adult Onset Still's disease or AOSD can also lead to chronic arthritis. Adult Onset Still's disease is a severe type of juvenile idiopathic arthritis (JIA), where JIA occurs in children and AOSD is found in adults. Adult-onset Still's disease affects multiple joints in the body, internal organs along with other parts of the body. Adult individuals who are aged above 45 years have a greater tendency to develop Adult Onset Still's Disease. AOSD can also develop in the later years. The exact cause of Adult Onset Still's disease or AOSD is not known and it does not have any known risk factors. A virus or some other infectious agent is thought to trigger Adult Onset Still's disease or AOSD; however, studies are still going on as to the proof of this theory.
There are only very few similarities between Adult-Onset Still's Disease and Juvenile Rheumatoid Arthritis, but AOSD is different from JIA. Adult Onset Still's disease or AOSD occurring in children is known as juvenile rheumatoid arthritis and is also termed as systemic-onset juvenile rheumatoid arthritis. Adult-Onset Still's Disease is more common in women than men.
Causes of Adult Onset Still's Disease or AOSD
The cause of Adult Onset Still's disease or AODS is not clear and Adult Onset Still's Disease has no known risk factors. Women are more often affected by Adult Onset Still's Disease than men. Adult Onset Still's disease or AOSD in children is termed as systemic juvenile idiopathic arthritis.
Signs & Symptoms of Adult Onset Still's Disease or AOSD
- Common symptoms of Adult Onset Still's disease or AOSD consist of fever, pain in the joints, sore throat and rash.
- Patient has pain in the joints along with swelling and warmth in the joints. Several joints are often affected at the same time.
- Patient with Adult Onset Still's disease also can have symptoms of joint stiffness in the morning, which persists for many hours.
- The onset of fever is abrupt and comes once in a day, commonly in the afternoon or evening.
- There is salmon-pink colored rash on the skin, which comes and goes with the fever.
- Patient can also have symptoms of pain and swelling in the abdomen.
- Pain can be felt upon taking deep breaths.
- Sore throat can also be experienced.
- There is swelling of the lymph nodes.
- Patient suffering from Adult Onset Still's disease loses his/her weight.
- Spleen enlargement or liver enlargement can also occur.
- Patient can also have inflammation of the heart and lungs.
Diagnosis of Adult Onset Still's Disease or AOSD
Diagnosis of Adult Onset Still's Disease is made after excluding other diseases. Different types of investigations are done to confirm the diagnosis of Adult Onset Still's Disease. Physical exam is done of the patient, which can show rash, fever and arthritis. The doctor uses a stethoscope to listen for any changes in the sound of the lungs and heart. Imaging tests such as CT scan and ultrasound of the abdomen, x-rays of the chest, joints or abdomen are done to check for inflammation in the joints, liver, chest and spleen. Blood tests are also done to diagnose Adult Onset Still's Disease and include:
- Complete blood count (CBC), which reveals an increased number of white blood cells (WBCs) and decreased number of red blood cells (RBCs).
- ESR (sedimentation rate), a measure of inflammation, will be higher than normal.
- C-reactive protein (CRP) test will be higher than normal.
- There will be increased level of fibrinogen and ferritin.
- Liver function test is done, which will reveal increased levels of AST and ALT in patients with Adult Onset Still's Disease.
- ANA and rheumatoid factor will be negative.
Treatment for Adult Onset Still's Disease or AOSD
The aim of treatment for Adult Onset Still's Disease or AOSD is to control and manage the symptoms of arthritis. For this purpose, medicines such as nonsteroidal anti-inflammatory drugs (NSAIDs), which include aspirin and ibuprofen, are prescribed first. In severe cases of Adult Onset Still's Disease, prednisone can be prescribed. In case of chronic and persistent Adult Onset Still's Disease, medicines which suppress the immune system (immunosuppressants) can be prescribed which include: Anakinra, Methotrexate and Tumor Necrosis Factor (TNF) antagonists, such as etanercept.
Prognosis of Adult Onset Still's Disease or AOSD
There is resolution of symptoms in about 1 in 5 patients, within a year and without any recurrence of symptoms. However, in many patients, symptoms do resolve, but recur many times over the next few years. In about 50% of patients with Adult Onset Still's Disease (AOSD), symptoms persist for a long time, i.e. the disease becomes chronic in nature.
Complications of Adult Onset Still's Disease or AOSD
Some of the complications of Adult Onset Still's Disease or AOSD include arthritis of multiple joints, pericarditis, liver disease, spleen enlargement and pleural effusion.