Adult onset Still disease
AOSD is characterized by spiking fevers that typically peak in the late afternoon or early evening, a pink or salmon-colored evanescent rash, polyarthralgia, hepatosplenomegaly, lymphadenopathy, and sore throat. Fever, rash, and arthralgias occur in most patients. Arthralgias and arthritis typically affect the knees, ankles, and wrists.
There are 3 different patterns in the clinical evolution of AOSD. The monocyclic pattern is self-limited and characterized by one flare of variable duration followed by complete remission. The polycyclic pattern is marked by 2 or more episodes with intervening symptom-free periods. The chronic articular pattern is characterized by severe joint manifestations that lead to joint-space narrowing and destruction. AOSD can also have serious systemic complications including serositis, chronic arthropathy, and macrophage activation syndrome. Late carpal ankylosis occurs in approximately 25% of patients and represents a distinct clinical feature differentiating AOSD from rheumatoid arthritis.
M06.1 – Adult-onset Still's disease
239920006 – Adult onset Still's disease
Differential Diagnosis & Pitfalls
- Infectious mononucleosis
- Scarlet fever
- Rheumatic fever
- Lyme disease
- Viral exanthems (rubella, coxsackievirus, parvovirus)