What is adult onset still's disease (AOSD)?
Adult-Onset Still’s Disease (AOSD) is a rare form of inflammatory arthritis that is characterised by fevers, rashes, and joint pain. AOSD can occur as a once-off episode, as a persistent condition, or as a recurring condition. The cause of AOSD is currently unknown.
There are many treatments available for AOSD that can help in the management of symptoms by reducing inflammation and muscle pain. As well as medications, there are many at-home recommendations to help alleviate symptoms, including remaining active and ensuring a balanced diet - both of which dampen negative side effects of various medications and help maintain movement range and pain.
The prognosis for AOSD is generally good; the symptoms can be managed, and the condition is not fatal. However, some complications of AOSD, such as macrophage activation syndrome, can be fatal.
Related disorders
There are many disorders that share the same symptoms as AOSD and are also marked by inflammation. The following are a variety of disorders that have overlapping symptoms with AOSD.
Autoinflammatory syndromes are a collection of conditions marked by recurring episodes of inflammation caused by dysfunctions of the immune system. Common symptoms of autoinflammatory syndromes include fevers, skin rashes, and muscle and joint pain. Examples of autoinflammatory syndromes include hyper immunoglobulin D syndrome (HIDS), cryopyrin-associated periodic syndromes (familial cold autoinflammatory syndrome and Muckle-Wells syndrome), Schnitzler syndrome, familial Mediterranean fever, and mevalonate kinase deficiency.1
Autoimmune disorders are a collection of conditions characterised by a malfunctioning immune system that mistakenly attacks healthy tissue instead of pathogens. Common symptoms of autoimmune disorders include chronic inflammation, fevers, skin rashes, and muscle and joint pain. Such disorders that can resemble the symptoms expressed in individuals with AOSD include rheumatoid arthritis, systemic lupus erythematosus, and dermatomyositis.1
Other conditions that may mimic the symptomatology of AOSD are inflammatory bowel disease (IBD); reactive arthritis; acute febrile neutrophilic dermatosis (also known as Sweet’s syndrome); various infections such as toxoplasmosis, mononucleosis, and, tuberculosis, and a number of cancers such as leukaemia and lymphoma.1
Signs and symptoms
The majority of individuals with AOSD experience a combination of the following:
- Sore throat
Lymph nodes in the neck may swell and may become tender to touch. This is one of the first signs of AOSD.
- Fever
A fever of at least 102 F (38.9 C) may occur on a daily basis for a week or more. Individuals may experience peaks in temperature in the later afternoon or early in the evening, with two fever spikes daily.
- Rash
Alongside bouts of fever, a rash may appear on the skin - particularly on the arms, legs, or the trunk.
- Muscle pain
Similar to rashes, muscle pain may occur alongside bouts of fever. Pain intensity can sometimes disrupt daily tasks and activities.
- Achy and swollen joints
You may experience stiffness, inflammation, and pain in the joints, particularly in the wrists and knees. These joint issues can last for at least a fortnight.2
Causes and risk factors
The cause of AOSD is uncertain. However, some research suggests that the condition may be triggered by a bacterial or viral infection. The primary risk factor of adult Still’s disease is age. Incidences of AOSD tend to peak at two points in time: once between 15 and 25 years, and again between 36 and 46 years. Sex may be a risk factor of AOSD, with some research showing a slightly higher prevalence in women.2,3
Complications
Most of the associated complications that can develop on AOSD are due to inflammation of joints and organs. Some of the most common complications include inflammation of the heart, joint destruction, excess fluid around the lungs, and macrophage activation syndrome.
Diagnosis
Diagnosis of AOSD involves a number of different tests, including imaging tests (exposing damage related to the condition) and blood tests (which help rule out other conditions with similar symptoms).
Treatment
There are a number of medications that are used to treat AOSD. The severity of your symptoms determines which medications will be prescribed.
Medicine
One of the main treatments for AOSD is a medication known as prednisone which helps control the inflammation. This is a steroid drug that most individuals with AOSD require.
Other popular medications for this condition include Nonsteroidal anti-inflammatory drugs (NSAIDs), which help alleviate inflammation and mild joint pains; Biologic response modifiers (for example infliximab [Remicade], and etanercept [Enbrel]), which help alleviate inflammation but their long-term benefit is unknown, and methotrexate, a drug often used in combination with prednisone that allows the prednisone dose to be lowered.2
Home remedies
There are a number of ways to protect your health with AOSD. Understanding your medications and listening to your doctor’s prescriptions can help reduce inflammation and make joint pain more manageable.
Dietary supplements may help prevent negative side effects of some medications (for example, prednisone can contribute to osteoporosis; incorporating more calcium and vitamin D into your diet may help prevent osteoporosis). Physical movement can also help relieve pain and stiffness, as well as helping maintain range of motion.2
Prognosis and life expectancy
The prognosis for AOSD is generally good; the symptoms can be managed and the condition is not fatal. The relapse rate of the condition is high. (For example, Appenzeller et al. report that around 75% of patients relapsed in 6.9 years of follow-up).
Complications of AOSD can be fatal, however. The inflammation caused by AOSD can build up around the lungs, making deep breathing difficult. Another complication of AOSD, macrophage activation syndrome, results in low blood cell counts, high levels of triglyceride, and abnormal liver functioning. This complication is rare but can lead to death.2
How long the condition may persist varies between individuals. However, some research suggests that the average duration of AOSD is a decade, with over half of patients continuing to require medication even ten years post-diagnosis.5
Current research
Current research on AOSD broadly aims to deepen our understanding of what exactly causes the condition, as well as improve treatment strategies and understanding the development of complications.4
Summary
Adult-onset Still’s disease (AOSD) is a rare inflammatory condition that is characterised by arthritis, a spiking and recurring fever, and skin rashes. It is a rare type of arthritis that is thought to be autoinflammatory or autoimmune-related. The cause of AOSD is currently unknown.
There are many treatments available for AOSD that help manage inflammation and muscle pain, as well as many at-home recommendations, including remaining active and having a balanced diet, to help with side effects of various medications.
Reference
- Rare Disease | Adult-Onset Still’s Disease. [website]. Accessed on: May 31 2022. Link: https://rarediseases.org/rare-diseases/adult-onset-stills-disease/
- Mayo Clinic | Adult Still’s disease [website]. Accessed on: May 31 2022. Link: https://www.mayoclinic.org/diseases-conditions/adult-stills-disease/symptoms-causes/syc-20351907#:~:text=Adult%20Still's%20disease%20is%20a,affected%20joints%2C%20particularly%20the%20wrists.
- Liu Z, Lv X, Tang G. Clinical features and prognosis of adult-onset Still's disease: 75 cases from China. Int J Clin Exp Med. 2015 Sep 15;8(9):16634-9.
- Tomaras S, Goetzke CC, Kallinich T, Feist E. Adult-Onset Still's Disease: Clinical Aspects and Therapeutic Approach. J Clin Med. 2021 Feb 12;10(4):733.
- Sampalis JS, Esdaile JM, Medsger TA Jr, Partridge AJ, Yeadon C, Senécal JL, et al. A controlled study of the long-term prognosis of adult Still's disease. Am J Med. 1995 Apr;98(4):384-8.
