Acute pericarditis

Article written and reviewed by Dr Luca Moretti

Acute pericarditis is a recent-onset inflammatory syndrome of the pericardium that may present with chest pain, a friction rub, electrocardiographic changes, and effusion, without these findings necessarily being present at the same time. In the ESC 2025 classification, the term acute identifies an onset within four weeks. The time reference describes the course and does not establish the cause, severity, or presence of myocardial injury: a small effusion associated with intense pain and inflammation with a rapidly compressive collection belong to the same temporal category, but require very different decisions.

The first episode often represents the entry point into the history of pericardial diseases. In settings with a low prevalence of tuberculosis, idiopathic or presumed viral diagnoses predominate; in immunosuppressed people, patients with cancer, and areas with high tuberculosis endemicity, the probability of individual etiologies changes substantially. Epidemiologic estimates also depend on recognition of mild cases, access to echocardiography, and the population studied. The frequency found among hospitalized patients therefore cannot be transferred directly to the general population.

Most uncomplicated idiopathic forms respond to medical therapy, but the initial assessment must promptly identify dangerous conditions and establish treatment capable of achieving stable remission. Symptoms that do not cease point toward incessant pericarditis; a new flare after a genuine interval of remission instead identifies recurrent pericarditis. These courses should not be considered inevitable, nor confused with isolated persistence of chest pain of another origin.

Etiology, risk factors, pathogenesis, and pathophysiology

Designation of an etiology as idiopathic indicates the absence of a demonstrated cause after an investigation proportionate to the clinical presentation. It is not equivalent to confirmation of a viral infection. A preceding respiratory or gastrointestinal syndrome makes an infectious trigger plausible, but does not prove that a particular virus reached the pericardium. Positive serum antibodies may likewise document previous exposure without identifying the agent responsible for the current inflammation. This distinction prevents a reasonable clinical hypothesis from being turned into a microbiologic diagnosis unsupported by data.

Among infectious causes, presumed viral forms are common in high-income countries, whereas tuberculosis is more important in appropriate epidemiologic settings and in HIV infection. Nontuberculous bacterial infections may reach the pericardial sac by contiguous spread from a thoracic focus, hematogenous dissemination, or after procedures and surgery. Purulent pericarditis is an invasive disease that requires source control and antibiotics, not a simple variant to be treated with anti-inflammatory drugs. Fungi and parasites are much less common and should be investigated on the basis of immunosuppression, exposures, and specific clues, avoiding indiscriminate panels when the pretest probability is low.

Noninfectious causes include systemic autoimmune diseases, autoinflammatory syndromes, uremia, neoplastic infiltration, radiation, and drug reactions. Lupus may produce serositis in the setting of systemic disease activity; a post-cardiac injury syndrome may occur after infarction, cardiac surgery, trauma, or an invasive procedure through immune mechanisms resulting from the injury. Early post-infarction pericarditis and late immune-mediated pericarditis are not equivalent in timing or implications. In patients with cancer, moreover, inflammation may be due to the neoplasm, an opportunistic infection, radiotherapy, or immunomodulatory treatment: a history of cancer alone does not resolve the causal diagnosis.

The risk factors must be distinguished from causes. Immunosuppression, recent surgery, advanced renal failure, tuberculosis exposure, connective tissue diseases, and antineoplastic therapies modify the probability of the different etiologies. High fever, a large effusion, and lack of response to therapy are instead mainly indicators of a potentially complicated course or a specific cause. Presenting the latter as factors that cause the disease would confuse predisposition, manifestation, and prognosis. A previous respiratory infection likewise has contextual value, not the value of a diagnostic test.

The inflammatory process involves the mesothelium, connective tissue, and pericardial microcirculation. Cellular injury makes endogenous danger signals available, while any microorganisms provide signals recognized by innate immunity. Activation of recognition receptors induces proinflammatory transcriptional programs and recruits myeloid cells. Activation of the NLRP3 inflammasome, a complex that promotes mediator maturation through caspase-1, has been documented in experimental models and tissue observations. These data support a role for interleukin-1 in part of pericardial biology, but do not demonstrate that every first episode is a monogenic disease or depends exclusively on this pathway.

Interleukin-1 contributes to leukocyte recruitment and amplification of the local response, while other mediators, including interleukin-6, contribute to the systemic acute-phase response. Increased microvascular permeability allows proteins and cells to pass into the cavity; extravasated fibrinogen may be converted into fibrin on the serosal surfaces. This results in roughening of the layers, reduced normal gliding, and, when exudation exceeds resorption, fluid accumulation. Fibrinous and serofibrinous forms describe this morphologic appearance without, by themselves, identifying the causal agent.

The pain depends mainly on irritation of the sensitive structures of the parietal pericardium and adjacent pleuropericardial regions. Involvement of phrenic afferents explains radiation toward the shoulder or trapezius ridge. Deep respiratory movements and certain postures alter the mechanical relationships between inflamed surfaces, accounting for the pleuritic component and the relief that may be obtained by sitting with the trunk leaning forward. Pain intensity does not measure effusion volume or the probability of tamponade: an almost dry form may be very painful and a large collection relatively painless.

Changes in the ECG are related to involvement of electrically active epicardial and subepicardial structures, not to autonomous electrical activity of the fibrous sac. Inflammation may alter ventricular repolarization and atrial vectors, producing diffuse ST-segment elevation and PR-segment depression. Their absence does not exclude the diagnosis. When cardiomyocyte injury is also present, troponin may increase: this finding requires characterization of any myocardial involvement and should not be interpreted simply as an index of the amount of pericardial inflammation.

The hemodynamic consequences of the effusion depend on the rate of accumulation, distensibility of the sac, and filling pressures. A rapidly enlarging collection may raise intrapericardial pressure while the volume is still relatively limited; slow formation instead allows some adaptation. Once the distension reserve is exceeded, small additional increases produce substantial pressure rises and impair cardiac filling. A different alteration is loss of elasticity due to edema and inflammatory thickening, which may generate transient constrictive physiology. Recognizing these mechanisms prevents every episode of dyspnea from being considered simply a consequence of pain or anxiety.

Clinical manifestations, history, and physical examination

The history begins by characterizing the chest pain: location, time of onset, rapidity of appearance, and relationship to breathing, cough, swallowing, exertion, and posture. Retrosternal or precordial location, worsening with inspiration, and improvement when sitting are suggestive, but no single feature is pathognomonic. Some patients describe pressure rather than a sharp pain; others have a lateral pleuritic component or scapular radiation. Overlap with ischemic pain requires particular caution when advanced age, coronary artery disease, autonomic symptoms, or hemodynamic instability coexist.

Dyspnea should be characterized by distinguishing limitation of inspiration due to pain from difficulty breathing at rest, orthopnea, and reduced exercise tolerance. The first mechanism is common in painful forms, whereas the others may indicate a hemodynamically significant effusion, myocardial involvement, or associated pulmonary disease. Palpitations, presyncope, syncope, and marked prostration require an active search for arrhythmias, hypoperfusion, and more extensive cardiac involvement. Fever and fatigue are compatible with inflammation, but persistent high fever, rigors, or systemic toxicity increase suspicion of a specific infectious cause.

The assessment of relevant history includes recent infections, tuberculosis contacts, travel and occupational exposures, cardiac procedures, thoracic surgery, trauma, and radiotherapy. The medication list should include new prescriptions, cancer treatments, anticoagulants, immunosuppressants, and medicines taken independently before the visit. An anti-inflammatory drug already used may attenuate fever and inflammatory markers without resolving the disease. A history of renal disease, neoplasia, HIV, or connective tissue disease modifies the choice of investigations and the threshold for hospitalization. It is not necessary to investigate every rare exposure indiscriminately when clinical plausibility is lacking.

The systemic review looks for features preceding or accompanying the serositis: arthritis, rash, photosensitivity, oral ulcers, Raynaud phenomenon, mucosal dryness, hematuria, recurrent febrile episodes, abdominal pain, and a family history of inflammatory syndromes. These findings acquire meaning as a whole. An isolated oral ulcer or modest antibody positivity is not sufficient to attribute the presentation to an autoimmune disease. A genuinely negative history, in a typical first episode with a rapid response, instead supports a limited initial approach without making exclusion of every rare disease a prerequisite for starting treatment.

On physical examination, temperature, heart rate and rhythm, blood pressure, oxygen saturation, respiratory rate, and signs of peripheral perfusion are assessed. Auscultation should be repeated at appropriate sites and positions because the pericardial friction rub may be intermittent. It has a superficial, scratching quality, may include multiple components during the cardiac cycle, and is often best heard along the left sternal border with the patient leaning forward. Persistence during a brief breath hold helps distinguish it from a pleural rub, without making the maneuver absolutely discriminatory. Its absence during a single examination has no exclusionary value.

Inspection of the jugular veins and assessment of pulsus paradoxus are essential when cardiac compression is suspected. An inspiratory decrease in systolic pressure greater than 10 mmHg, measured correctly, may support suspicion of tamponade, but it is affected by respiratory conditions and is not mandatory in every presentation. Hypotension, tachycardia, cold extremities, and altered mental status indicate more advanced compromise. The classic combination of hypotension, jugular venous distention, and muffled heart sounds has low sensitivity: waiting for it to be complete may delay treatment.

The examination is completed by assessing breath sounds, pleural effusions, peripheral edema, hepatomegaly, rash, and joint signs. Pulmonary crackles and a third heart sound suggest a myocardial contribution or another cause of heart failure; focal respiratory findings also point toward pneumonia, pleuritis, or pneumothorax. Reassessment after analgesia may clarify how much tachycardia or tachypnea is due to pain, but does not replace monitoring of vital signs. An apparently stable person may deteriorate if the pericardial collection grows rapidly or if the initial diagnosis missed an acute vascular condition.

Initial investigations, diagnostic criteria, and differential diagnosis

The initial assessment must answer three questions: whether the presentation is truly pericardial, whether there is an immediate threat, and whether there are clues to a cause requiring specific treatment. The electrocardiogram (twelve-lead), transthoracic echocardiography, and essential blood tests form the core of the investigation. The diagnosis arises from convergence of findings, not isolated use of a test. A normal ECG, an echocardiogram without effusion, or an initially normal C-reactive protein level does not individually rule out a pericardial inflammatory process.

The 2025 ESC Guidelines distinguish the degree of diagnostic certainty and include tissue imaging among the additional elements. The clinical presentation must be compatible, typically pericarditic chest pain or an equivalent presentation that raises suspicion. More than one additional criterion is required for a definite clinical diagnosis; with only one, the presentation falls into the possible category and may require further evaluation. It is essential not to combine criteria taken from different classifications or count separately multiple manifestations belonging to the same item.

Additional elements for the clinical diagnosis of pericarditis according to ESC 2025, to be interpreted together with a compatible presentation.

• Pericardial friction rub documented on auscultation.
• Characteristic electrocardiographic changes, such as diffuse ST-segment elevation or PR-segment depression.
• Elevated C-reactive protein.
• New or worsening pericardial effusion.
• Pericardial edema and/or late gadolinium enhancement of the pericardium on cardiac magnetic resonance imaging.

The historical ESC 2015 model required at least two of typical pain, friction rub, ECG changes, and effusion, considering other findings supportive. The ACC 2025 document instead uses a suggestive presentation associated with at least one additional finding. These frameworks explain why case series and studies from different periods are not fully comparable. In practice, it is useful to state the system adopted and describe the actual findings: classification should not conceal diagnostic uncertainty or become a reason to overlook an urgent alternative diagnosis.

On ECG, ST-segment elevation tends to involve multiple territories and may be associated with PR-segment depression, with opposite changes in aVR. The classic evolution through ST normalization and T-wave inversion is inconsistent and may be modified by treatment. A territorial pattern, extensive reciprocal ST-segment depression, new Q waves, or strongly ischemic pain require evaluation for an acute coronary syndrome. Concave ST elevation and pleuritic pain, taken in isolation, are not sufficient to exclude it. If coronary suspicion remains significant, the urgent diagnostic and therapeutic pathway should not be delayed while waiting to confirm pericarditis.

Blood tests include C-reactive protein, complete blood count, renal function, electrolytes, and troponin; erythrocyte sedimentation rate may add information, but has slower kinetics. CRP may be normal in the very first hours or after treatment has already begun, whereas an increase is not specific to the pericardium. Subsequent measurement is useful when clinical suspicion remains high and for following the course of an initially elevated value. Troponin documents myocardial injury: its interpretation requires the time course, ECG, ventricular function, and context, without automatically equating every increase with infarction or clinically severe myocarditis.

Echocardiography assesses the amount, distribution, and consequences of fluid, biventricular function, and any hemodynamic abnormalities. The traditional end-diastolic measurement distinguishes small collections of less than 10 mm, moderate collections between 10 and 20 mm, and large collections greater than 20 mm; the measurement must be contextualized because a loculated collection is not adequately described by a single number. Right-sided chamber collapse, respiratory variation in flows, and inferior vena cava dilation may indicate a compressive effect, but should be correlated with ventilation, volume status, and pulmonary pressures. The presence of an effusion alone, even a large one, is not equivalent to tamponade.

The chest radiograph may identify alternative pulmonary diagnoses and pleural effusions; a normal cardiac silhouette does not exclude pericarditis or acute tamponade. Magnetic resonance imaging is particularly useful in uncertain cases, when myocardial involvement is suspected, or when symptoms and basic investigations do not agree. Water-sensitive sequences look for edema, whereas late gadolinium enhancement, or LGE, documents increased distribution of contrast within altered tissue. Residual enhancement may persist after clinical control and should not be interpreted without considering edema, the course, and treatment. CT better addresses questions about calcifications, thoracic anatomy, masses, and some collections, but is not mandatory in a typical first episode.

The differential diagnosis includes, first of all, acute coronary syndrome, aortic dissection, pulmonary embolism, and pneumothorax. Sudden maximal pain, neurologic deficits, or pulse asymmetry suggest aortic disease; disproportionate dyspnea, hypoxemia, and a thromboembolic context require a dedicated pathway for embolism. Tests such as D-dimer, CT angiography, or coronary angiography are selected according to clinical probability, not as a fixed pericarditis panel. Other considerations include pleuritis, pneumonia, reflux, esophageal disease, and chest wall pain. Reproducibility on palpation may be informative, but does not by itself eliminate cardiopulmonary risk. Improvement after an NSAID is not a specific diagnostic test.

Risk stratification and disease definition

After recognizing the syndrome, risk stratification determines the setting of care and depth of etiologic investigation. Fever above 38 °C, subacute onset, large effusion, tamponade, and lack of response to aspirin or NSAIDs after at least one week are established risk features. Immunosuppression, trauma, oral anticoagulation, and myocardial involvement are additional elements that may modify management. They do not all have identical prognostic weight and do not constitute a score to be added mechanically; rather, they indicate when the probability of a specific cause or complication makes minimal management inappropriate.

Hospitalization is required in the presence of instability, suspected invasive infection, tamponade, major arrhythmias, or significant ventricular dysfunction, and is generally indicated when high-risk features emerge or urgent investigation is needed. A low-risk patient with stable parameters, controllable pain, and the possibility of reliable follow-up can be managed as an outpatient. The ability to return promptly if the condition worsens and access to early reassessment are part of the clinical decision. Discharge based only on young age or a small effusion does not meet these requirements.

Investigation of specific causes is guided by the findings. High fever and suspected bacteremia require blood cultures and a search for the focus, preferably before antibiotics when this does not delay their necessary initiation. Suspected tuberculosis integrates epidemiology, imaging, and any microbiologic samples; a positive immunologic test identifies sensitization and does not by itself demonstrate pericardial localization. HIV testing is appropriate when the clinical context or risk suggests it. Extensive viral serologies, by contrast, rarely change management of an uncomplicated first episode and may generate erroneous causal attributions.

Suspected systemic disease justifies targeted investigations, such as urinalysis, indices of organ function, and autoantibodies selected according to the presentation. Interpretation should precede ordering: a low antibody titer in the absence of compatible manifestations has a different meaning from the same result in polyserositis with arthritis and nephropathy. In people with cancer, weight loss, a large effusion, or suspicious thoracic findings, investigation for malignancy may require CT and fluid analysis. Cytologic examination, when indicated, answers a different question from simple confirmation of inflammation.

Any myocardial involvement should be defined by ventricular function, magnetic resonance imaging, and rhythm monitoring according to severity. A predominantly pericardial presentation with elevated injury biomarkers and preserved function differs from a presentation with heart failure, ventricular arrhythmias, or reduced contractility. Traditional terminology distinguishes myopericarditis and perimyocarditis according to the predominant involvement, but actual phenotype is what guides risk. Troponin and magnetic resonance imaging may therefore change monitoring indications, the duration of exercise restriction, and criteria for return to activity even when pain responds rapidly.

Pericardiocentesis is not a routine investigation in a first episode. It is performed for a therapeutic indication, particularly compressive compromise, or for an important etiologic question, such as suspected bacterial infection or neoplasia in an appropriate context. Cytology and microbiology are planned on the fluid according to the suspicion, avoiding attribution of absolute value to a single biochemical parameter. Pericardial biopsy may be useful in selected persistent or unresolved cases, especially when the result would change treatment. Endomyocardial biopsy has its own indications in myocardial diseases and does not follow automatically from a diagnosis of pericarditis.

Treatment, monitoring, and prognosis

Treatment of low-risk idiopathic or presumed viral forms aims to control inflammation and prevent continuation or reactivation of the disease. The combination of aspirin or NSAIDs and colchicine is the usual initial treatment when there are no contraindications. Anti-inflammatory doses differ from the small analgesic doses taken occasionally; continuity of administration is also relevant. The choice should consider renal function, bleeding history, gastrointestinal disease, heart failure, blood pressure, and concomitant therapies, without applying a standard regimen to every patient.

In adults, commonly used regimens include ibuprofen 600-800 mg every eight hours or aspirin 750-1,000 mg every eight hours. The full-dose phase often lasts one or two weeks in uncomplicated forms, but is adjusted according to clinical response and normalization of CRP when it was initially elevated. This is followed by gradual tapering, not early discontinuation as soon as pain subsides. Aspirin is particularly appropriate when it is already required for ischemic disease. Two NSAIDs are not routinely combined to increase efficacy, because this mainly increases toxicity. Gastric protection with a proton pump inhibitor generally accompanies these regimens.

Colchicine interferes with microtubule dynamics and cellular functions involved in the inflammatory response, complementing the effect of anti-inflammatory drugs. In adults with adequate renal and hepatic function, 0.5 mg once daily is often used for body weight below 70 kg and 0.5 mg twice daily from 70 kg upward, without a loading dose. In the first episode, the usual duration is at least three months. The ICAP trial, involving 240 patients, found a combined outcome of an incessant course or recurrence in 16.7% of the colchicine group compared with 37.5% of the placebo group, both added to conventional therapy. The result supports early use without guaranteeing the absence of recurrence in an individual patient.

Drug safety requires particular attention to colchicine: diarrhea and gastrointestinal disturbances may limit its use, whereas cytopenias and neuromuscular toxicity are more serious events. Reduced renal elimination, liver disease, and interactions with CYP3A4 or P-glycoprotein inhibitors may increase exposure. Macrolides such as clarithromycin, some azoles, cyclosporine, and other relevant combinations should be assessed before prescribing; coexisting organ failure may make some combinations contraindicated. The dose may require reduction or the drug may be inappropriate. Muscle weakness, persistent vomiting, or severe diarrhea should not be managed by empirically increasing treatment.

Corticosteroids are not the usual choice for a first idiopathic episode. They may be necessary when there is a specific indication, such as active autoimmune disease, or when aspirin and NSAIDs are contraindicated or not tolerated and other options are insufficient. Before immunosuppression, suspected infection, especially bacterial or tuberculous infection, must be addressed. When indicated, prednisone is generally used at low or moderate initial doses, approximately 0.2-0.5 mg/kg/day, with colchicine when possible and slow tapering after disease control. Unjustified high doses and excessively rapid reductions may promote treatment dependence and flares, in addition to metabolic and infectious toxicity.

Lack of response after one week does not simply justify an automatic switch to corticosteroids. Diagnosis, the dose actually taken, adherence, interactions, and the presence of a specific cause or complication should be reassessed. In cases with documented persistent inflammation, specialist strategies may be necessary, including interleukin-1 blockade in appropriate incessant or recurrent phenotypes. Anakinra and rilonacept are not universal therapy for a first uncomplicated pericarditis episode. Azathioprine, immunoglobulins, and surgery have selected roles in refractory disease and do not replace appropriate first-line treatment.

Etiologic treatment takes precedence when the cause is identified. A purulent collection requires effective drainage and targeted antimicrobial therapy after appropriate initial empiric treatment. Tuberculosis requires a combination of antimycobacterial drugs according to the clinical and infectious-disease context; uremic disease requires review of dialysis management. In neoplastic syndromes and toxicities from cancer treatments, shared decision-making among specialists is necessary because control of pericardial disease also depends on control of the causal disease. There is no general indication for empiric antiviral therapy in all forms preceded by a respiratory infection.

Exercise restriction accompanies the active phase. Sports and strenuous exertion are avoided while symptoms and signs of disease persist; return is planned after clinical remission and adequate reassessment, considering activity intensity, biomarkers, ECG, and relevant imaging. Myocardial involvement, arrhythmias, and ventricular dysfunction require more cautious criteria and a dedicated pathway. Normalization of pain with analgesics is not sufficient to authorize immediate return to competitive training. At the same time, after remission, an unjustified indefinite ban may contribute to deconditioning and fear of physical activity.

Early follow-up, generally within about one week in cases managed outside the hospital, assesses pain, fever, tolerability, adherence, and trends in inflammatory markers. Echocardiography is repeated according to the initial effusion and clinical course, especially if dyspnea or tachycardia increases, signs of congestion appear, or the response is unsatisfactory. It is not necessary to repeat all tests indefinitely in an asymptomatic person with an uncomplicated course. It is instead essential to document remission before the more substantial treatment reductions and to check renal function during prolonged anti-inflammatory regimens or in vulnerable individuals.

Advanced age, pregnancy, comorbidities, and renal failure require substantial adaptation. In older adults, the risk of bleeding and interactions may outweigh the benefits of standard doses; in kidney disease, an NSAID may worsen filtration, fluid retention, and hyperkalemia. In pregnancy, the choice also depends on gestational age, and NSAID use has specific limitations: the regimen for a nonpregnant adult cannot be applied automatically. Children require weight-based doses and pediatric assessment. In all these settings, the need to modify treatment does not in itself prove greater disease aggressiveness, but reflects a different safety margin.

Prognosis of uncomplicated idiopathic pericarditis is generally favorable for survival and cardiac function. The most frequent problem is persistence or recurrence, which can be reduced but not abolished by appropriate treatment. The risk of constriction is strongly related to etiology: in the prospective cohort of 500 first episodes studied by Imazio and colleagues, constriction developed in 2 of 416 idiopathic or viral cases and in 7 of 84 cases with a different etiology during follow-up. These data do not describe an individual's fate, but show why the cause and initial characteristics matter more than pain intensity alone.

Complications and consequences of the first episode

Persistent inflammation is one possible initial course. Pain and other signs may not disappear completely, or may flare again during an overly early reduction of therapy without a true symptom-free interval. This course differs from recurrence after remission and requires verification of disease control, diagnostic accuracy, and the possible presence of a still-active cause. Not every residual pain indicates this complication: musculoskeletal disease, reflux, or pain associated with breathing may coexist and should be distinguished from inflammation through a proportionate reassessment.

Cardiac tamponade occurs when pressure from the collection limits filling and reduces cardiac output. It may evolve with tachycardia, dyspnea, hypotension, oliguria, and hypoperfusion; in loculated collections after procedures, compression may be regional and present less classically. Urgent drainage is the definitive treatment when there is hemodynamic compromise due to fluid. Oxygen, circulatory support, and fluid management may have a temporary role, but do not eliminate the mechanical cause. Positive-pressure ventilation and drugs that reduce preload may worsen a filling-dependent situation and require particular caution.

Transient constriction results from reduced distensibility during the inflammatory phase and may regress with control of inflammation. Persistent constriction instead results from fibrous organization and, in some cases, calcification, with altered diastolic filling and systemic congestion. The distinction is based on history, Doppler, magnetic resonance imaging, and the course, not pericardial thickness alone. An effusion associated with signs of constriction also raises the issue of an effusive-constrictive form. Ascites and edema appearing after an apparently resolved episode therefore warrant renewed hemodynamic assessment.

Myocardial involvement may accompany pericarditis from the onset rather than representing a mandatory late complication. When clinically relevant, it modifies the risk of arrhythmias, heart failure, and functional limitation. A modestly elevated troponin level with preserved function does not automatically entail these outcomes, whereas ventricular arrhythmias, syncope, or dysfunction require specific management. Surveillance should therefore follow the type of injury actually demonstrated, avoiding both minimizing it as a detail of pericarditis and assigning an unfavorable prognosis to every increase in biomarkers.

Iatrogenic complications include gastrointestinal bleeding, renal injury, and sodium and water retention from NSAIDs, colchicine toxicity, and consequences of corticosteroid exposure. They may mimic the disease or limit its treatment: dyspnea from fluid retention, for example, should not automatically be attributed to increasing effusion. Prevention requires appropriate doses, review of drug combinations, gastric protection when indicated, and selected monitoring. An overly rapid taper of a corticosteroid taken long term may also produce systemic symptoms that do not necessarily coincide with reactivation of pericardial inflammation.

Finally, a painful or uncertain convalescence may impair quality of life, sleep, and work activity. Precise information about treatment, warning signs, and recovery criteria reduces both delays in reassessment and unjustified restrictions. Worsening dyspnea, syncope, hypotension, persistent fever, or new pain with different features require urgent reassessment. Closure of the episode does not coincide merely with the end of a prescription: it requires recovery consistent with the clinical findings and a plan for treatment withdrawal and return to activities appropriate to the disease actually observed.

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