Model Answer
0 min readIntroduction
Kawasaki Disease (KD), also known as mucocutaneous lymph node syndrome, is an acute, self-limited vasculitis of unknown etiology that primarily affects young children. First described by Tomisaku Kawasaki in 1967, it is the leading cause of acquired heart disease in developed countries. While the exact cause remains elusive, a combination of genetic predisposition and environmental triggers, potentially infectious agents, are believed to be involved. Early diagnosis and treatment are crucial to prevent long-term cardiovascular complications, particularly coronary artery aneurysms. This answer will detail the clinical picture of Kawasaki Disease, assuming a typical presentation.
Diagnosis: Kawasaki Disease
Based on the assumption of a typical presentation in a young child, the diagnosis is Kawasaki Disease. The diagnosis is primarily clinical, relying on a set of characteristic signs and symptoms. It's important to note that not all criteria need to be present for diagnosis, especially in atypical cases.
Clinical Picture of Kawasaki Disease
The clinical course of Kawasaki Disease is typically divided into three phases: acute, subacute, and convalescent.
1. Acute Phase (First 1-2 Weeks)
- Fever: High fever (typically >39°C / 102.2°F) lasting for at least 5 days is the hallmark of KD. The fever is often unresponsive to antibiotics and antipyretics.
- Conjunctivitis: Bilateral, non-exudative conjunctival injection (redness of the eyes) without pain or discharge.
- Oral Changes: Erythema (redness), cracking, and fissuring of the lips, strawberry tongue (red and bumpy tongue), and redness of the oral mucosa.
- Rash: Polymorphous exanthem (rash) – varies in appearance, often a maculopapular rash on the trunk and perineum.
- Cervical Lymphadenopathy: Acute, unilateral or bilateral cervical lymphadenopathy (swollen lymph nodes in the neck), typically >1.5 cm in diameter.
- Changes in Extremities: Erythema and edema (swelling) of the hands and feet, followed by desquamation (peeling) of the skin, particularly around the fingertips and toes, usually in the subacute phase.
2. Subacute Phase (Weeks 2-4)
- Desquamation: Peeling of the skin on the hands and feet is prominent during this phase.
- Coronary Artery Aneurysms: This is the most serious complication and can develop during this phase. Echocardiography is crucial for monitoring.
- Carditis: Myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the sac surrounding the heart) can occur, leading to arrhythmias and heart failure.
- Joint Pain: Arthralgia (joint pain) and arthritis may develop.
- Gastrointestinal Symptoms: Diarrhea, vomiting, and abdominal pain can persist.
3. Convalescent Phase (Weeks 4-8)
- Resolution of Symptoms: Fever subsides, and other acute symptoms gradually resolve.
- Continued Monitoring: Echocardiography is continued to monitor for coronary artery abnormalities.
- Elevated Inflammatory Markers: Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels may remain elevated for several weeks.
Diagnostic Criteria
The American Heart Association (AHA) guidelines for diagnosing Kawasaki Disease require the presence of fever for at least 5 days plus at least four of the following five principal clinical features:
| Clinical Feature | Description |
|---|---|
| Conjunctivitis | Bilateral, non-exudative |
| Oral Changes | Strawberry tongue, lip changes |
| Rash | Polymorphous exanthem |
| Lymphadenopathy | Cervical, >1.5 cm |
| Extremity Changes | Erythema, edema, desquamation |
Incomplete or atypical Kawasaki Disease can occur, making diagnosis challenging. These cases may present with fewer than four principal features but have significant inflammation and coronary artery abnormalities.
Conclusion
Kawasaki Disease is a serious systemic vasculitis requiring prompt diagnosis and treatment to minimize the risk of long-term cardiovascular complications. Recognizing the characteristic clinical features, understanding the phases of the illness, and utilizing diagnostic criteria are essential for effective management. Ongoing monitoring with echocardiography is crucial, even after the acute phase, to detect and manage potential coronary artery aneurysms. A high index of suspicion is necessary, particularly in cases with atypical presentations.
Answer Length
This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.