Still's Disease and Its Relationship to Pericarditis and Splenomegaly

Yes, Adult-Onset Still's Disease (AOSD) can cause both pericarditis and splenomegaly as part of its systemic inflammatory manifestations.

Clinical Manifestations of Still's Disease

Fever (typically spiking with temperature ≥39°C for at least 7 days) is present in approximately 95.7% of patients with AOSD 1
Characteristic salmon-pink, evanescent rash that often coincides with fever spikes, predominantly found on the proximal limbs and trunk, occurs in 51-87% of patients 1
Sore throat/pharyngitis is common, reported in 35-92% of patients 1
Myalgia occurs in 56-84% of patients 1

Splenomegaly occurs in 14-65% of patients with AOSD, with an average incidence of approximately 32% across multiple studies 1
Pericarditis is reported in 10-37% of patients with AOSD, making it one of the significant cardiac manifestations 1
Lymphadenopathy is present in 32-74% of patients 1
Pleuritis occurs in 12-53% of patients 1

Pericarditis is the most common cardiac manifestation of AOSD 2
In severe cases, pericarditis can progress to cardiac tamponade, which is a rare but potentially life-threatening complication 3
Case reports have documented severe AOSD presenting with constrictive pericarditis requiring aggressive treatment 4, 5

High levels of inflammation are typically identified by:
- Neutrophilic leukocytosis (often >15,000 cells/μL) 1
- Elevated C-reactive protein (CRP) 1
- Markedly elevated serum ferritin (often >1,000 ng/mL) 1
Elevated serum IL-18 and/or S100 proteins (calprotectin) strongly support the diagnosis and should be measured if available 1

The Yamaguchi criteria (most sensitive at 93.5%) include major criteria (fever, arthralgia, typical rash, leukocytosis) and minor criteria (sore throat, lymphadenopathy/splenomegaly, liver dysfunction, negative RF and ANA) 1
The presence of both splenomegaly and pericarditis in a patient with fever, rash, and arthralgia strongly supports the diagnosis of AOSD 1

IL-1 inhibitors (such as anakinra) or IL-6 receptor inhibitors (such as tocilizumab) should be initiated as early as possible when the diagnosis is established 1, 6
These biologics show the highest level of evidence for efficacy and safety in managing AOSD 6

For pericarditis or other severe systemic manifestations, high-dose glucocorticoids are often required initially 6
Case reports have shown successful treatment of AOSD with pericarditis using tocilizumab in addition to corticosteroids and cyclosporin A 4
For pericardial tamponade, a life-threatening complication, high-dose methylprednisolone pulse therapy may be required, sometimes in combination with surgical drainage 2, 3

Regular assessment of disease activity with adjustment of therapy is recommended 1
Patients should be actively screened and monitored for severe complications, including macrophage activation syndrome (MAS) and lung disease 1

The clinical course of AOSD typically falls into three patterns, each affecting about one-third of patients 1, 6:
- Self-limited/monocyclic pattern: systemic symptoms with remission within 1 year
- Intermittent/polycyclic pattern: recurrent flares with complete remission between episodes
- Chronic articular pattern: dominated by joint manifestations that can lead to severe joint destruction
Patients with systemic disease generally have a favorable prognosis, though serious complications like pericarditis, tamponade, and hepatic disease can occur 1

Early diagnosis and prompt initiation of appropriate therapy are crucial to prevent complications 6
For difficult-to-treat cases, consulting with specialized centers is recommended 1
The presence of both splenomegaly and pericarditis suggests significant systemic inflammation and may indicate a need for more aggressive therapy 1, 6