Adult-onset Still's disease

Adult-onset Still's disease
Synonyms	AOSD
Pronounce	N/A
Specialty	N/A
Symptoms	Fever, rash, arthritis, sore throat, lymphadenopathy, hepatosplenomegaly
Complications	Macrophage activation syndrome, chronic arthritis
Onset	Typically between ages 16 and 35
Duration	Variable
Types	N/A
Causes	Unknown
Risks	Unknown
Diagnosis	Based on clinical criteria, exclusion of other conditions
Differential diagnosis	Rheumatoid arthritis, systemic lupus erythematosus, infection, malignancy
Prevention	N/A
Treatment	NSAIDs, corticosteroids, DMARDs, biologic agents
Medication	Methotrexate, anakinra, tocilizumab
Prognosis	Variable; some patients experience chronic disease
Frequency	Rare
Deaths	N/A

Adult-onset Still's disease (AOSD) is a form of Still's disease, a rare systemic autoinflammatory disease characterized by the classic triad of persistent high spiking fevers, joint pain, and a distinctive salmon-colored bumpy rash. The disease is considered a diagnosis of exclusion. Levels of the iron-binding protein ferritin may be extremely elevated with this disorder. AOSD may present in a similar manner to other inflammatory diseases and to autoimmune diseases, which must be ruled out before making the diagnosis.

Signs and symptoms

The disease typically presents with joint pain, high fevers, a salmon-pink macular or maculopapular rash, enlargement of the liver and spleen, swollen lymph nodes, and a neutrophil-predominant increased white blood cell count in the blood.

Pathophysiology

The cause of adult-onset Still's disease is unknown, but it presumably involves interleukin-1 (IL-1), since medications that block the action of IL-1β are effective treatments. Interleukin-18 is expressed at high levels.

Diagnosis

The diagnosis is clinical, not based upon serology.

Major criteria	Minor criteria
Fever of at least 39 ¬∞C for at least one week	Sore throat
Arthralgias or arthritis for at least two weeks	Lymphadenopathy
Nonpruritic salmon-colored rash (usually over trunk or extremities while febrile)	Hepatomegaly or splenomegaly
Leukocytosis (10,000/microL or greater), with granulocyte predominance	Abnormal liver function tests
	Negative tests for antinuclear antibody and rheumatoid factor

Classification

People with AOSD generally experience one of two patterns in the disease:

• a debilitating pattern of fevers, pain, and other systemic symptoms, or
• a somewhat less aggressive pattern, in which the main symptom is arthritis and chronic joint pain.

Treatment

Adult-onset Still's disease is treated with anti-inflammatory medications. Steroids such as prednisone are used to treat severe symptoms of Still's. Other commonly used medications include hydroxychloroquine, penicillamine, azathioprine, methotrexate, etanercept, anakinra, tocilizumab cyclophosphamide, adalimumab, rituximab, and infliximab. Newer medications target interleukin-1 (IL-1), particularly IL-1β. A randomized, multicenter trial reported better outcomes in a group of 12 patients treated with anakinra than in a group of 10 patients taking other disease-modifying antirheumatic drugs.

Epidemiology

Adult-onset Still's Disease is rare and has been described all over the world. The number of new cases per year is estimated to be 1.6 per 1,000,000 population.

Prognosis

Prognosis is usually favorable but manifestations of the disease affecting the lungs, heart, or kidneys may occasionally cause severe life-threatening complications.

See also

• Juvenile idiopathic arthritis