Still’s disease is a rare inflammatory condition characterized by arthritis along with recurrent orange-to-pink colored skin rashes and high spiking fevers. It is named after George Frederic Still, an English pediatrician.
The condition is more commonly observed in children, known as systemic-onset juvenile idiopathic arthritis (SOJIA). In adults, it is referred to as adult-onset Still’s disease (AOSD). AOSD has relatively less prevalence (1 in 100,000 adults) compared to SOJIA. Also, AOSD is found to be more common in females.
Various theories exist pertaining to the etiology of Still’s disease. Few of them point towards autoimmune trigger, while others suggest that it might occur because of a microbial infection. A conclusive origin of the disease and risk factors still remains uncertain.
The majority of patients with Still’s disease suffer from high spiking fever of approximately 39°C or even higher, which returns to normal temperature within a few hours. The fever occurs recurrently during the same time of the day (commonly in the afternoon or evening). Some patients experience multiple fever episodes within a single day.
Salmon-to-pink colored skin rashes are also commonly seen in patients with Still’s disease. Rashes mainly appear on the chest region and thighs, and less commonly on upper and lower limbs. Appearance of rashes is also usually in sync with the fever spikes. The extent of itchiness of the rashes varies amongst the patients.
Still’s disease causes inflammation of lymph nodes in the neck region, which results in a sore throat. This is one of the early signs of Still’s disease, but is often mistaken for common throat infections.
Joint pain, especially in the knees, shoulders, wrists, ankles, and elbows is frequently reported. Swelling, stiffness, and warm sensation (referred to as “calor”) of joints are also observed alongside the pain. These are more prominent during early morning hours, and may last for a couple of weeks or more.
Some patients also complain of severe fatigue and muscular pain (myalgia) during the fever episodes. Other symptoms include abdominal swelling, pain, and weight loss. Pleurisy (pain while breathing), inflammation of visceral organs (such as lungs known as pleuritis, spleen, liver, heart known as myocarditis or pericarditis), and pleural effusion (accumulation of fluid in lungs) are also observed in some cases.
Due to similarity of certain symptoms with other conditions, such as systemic lupus erythematosus, rheumatoid arthritis, systemic infection, or lymphoma, diagnosis often becomes difficult. Moreover, the frequency of recurrence and severity of symptoms vary substantially amongst the patients. In general, a chronic form of Still’s disease can cause potentially debilitating long-term complications, if it remains untreated.
Diagnosis of Still’s disease is often confounded by the varying degree of symptoms. There is no single diagnostic test available for Still’s disease. Diagnosis is typically done by observation of aforementioned clinical symptoms, and by ruling out other possible conditions.
In order to make a firm diagnosis of Still’s disease, the arthritic symptoms must have persisted for a minimum of six weeks. In general, multiple joints are inflamed (polyarticular arthritis). X-ray scans are often performed to check the damage to joints and internal organs because of inflammation.
Blood tests reveal significantly high levels of white blood cells indicating a systemic infection, which in fact does not exist. Low red blood cell counts (anemia), and increased erythrocyte sedimentation rate and C-reactive protein level (indicating inflammation) are also observed.