Can older people get Kawasaki disease? A detailed overview
Kawasaki disease (KD) is an acute, systemic vasculitis, or inflammation of the blood vessels, that predominantly affects young children. The most common manifestation of KD is in children under the age of five, where it is a leading cause of acquired heart disease. However, its occurrence in older children and adults, while rare, is a serious medical concern. The rarity of adult-onset KD means that physicians, including those in primary care, may not immediately consider it in their differential diagnosis, especially when symptoms present atypically. A high index of suspicion is therefore critical for prompt diagnosis and intervention. The clinical presentation, diagnostic process, and treatment protocols for adult-onset KD have notable differences compared to the more familiar pediatric version.
Clinical differences: Adult vs. childhood Kawasaki disease
Adult-onset Kawasaki disease presents several important distinctions from the pediatric form. While both typically involve a prolonged fever and other classic signs, the frequency of certain symptoms varies significantly. Adults are less likely to develop certain symptoms, but more likely to experience others, which contributes to diagnostic challenges.
Common symptoms in adult-onset Kawasaki disease:
- Prolonged fever: A fever lasting for more than five days is a hallmark of the condition. In adults, this fever can be high-grade and resistant to standard fever-reducing medications.
- Cervical lymphadenopathy: Swollen lymph nodes in the neck are much more frequent in adults, occurring in up to 93% of cases, compared to 15% of children. This can lead to misdiagnosis as a typical bacterial infection.
- Joint pain and arthritis: Adults more commonly experience severe joint pain (arthralgia) and arthritis, affecting up to 61% of cases versus 24-38% in children.
- Hepatitis: Inflammation of the liver is observed in approximately 65% of adults, compared to only 10% of children.
- Mucocutaneous changes: Both adults and children develop red eyes (conjunctivitis), red and cracked lips, and a "strawberry" tongue.
- Extremity changes: Redness and swelling of the palms and soles are also common, followed by skin peeling (desquamation) in the later stages.
The risk of delayed diagnosis in older people
For older individuals, a missed or delayed diagnosis of KD can have devastating consequences. When treatment with intravenous immunoglobulin (IVIG) is delayed beyond the first 10 days of the illness, the risk of developing coronary artery aneurysms (CAA) rises significantly. In adults, CAA formation is less common than in children, but it is a severe complication when it does occur. A study published in Circulation showed that coronary artery sequelae of undiagnosed KD in childhood can contribute to early-onset ischemic heart disease in young adults. Therefore, in older people presenting with compatible symptoms and no other clear diagnosis, KD should be considered.
Diagnostic challenges and evaluation
Diagnosing adult-onset KD is a multi-step process that often requires a thorough clinical evaluation to rule out other febrile illnesses. Since no single diagnostic test exists, the diagnosis relies on a constellation of clinical signs and symptoms. The presence of unexplained prolonged fever for at least five days, combined with at least four out of five principal clinical features (conjunctivitis, oral changes, rash, extremity changes, and lymphadenopathy), is required for a classic diagnosis. However, an increasing number of cases present as "incomplete" or "atypical" KD, where fewer than four of the principal criteria are present.
Diagnostic workup often includes:
- Blood tests: Look for elevated inflammatory markers (C-reactive protein and erythrocyte sedimentation rate), anemia, and changes in white blood cell and platelet counts.
- Echocardiography: A key tool for assessing the coronary arteries for dilation or aneurysm formation, and for evaluating cardiac function.
- Cardiac imaging: For patients with heart-related complications, imaging modalities like CT coronary angiography (CTCA) or cardiac MRI (CMRI) may be used for a more detailed evaluation.
Treatment and prognosis in older adults
The primary goal of treatment for acute Kawasaki disease, regardless of age, is to reduce inflammation and prevent or minimize coronary artery damage. Treatment protocols for adults mirror those for children and generally involve a single high dose of intravenous immunoglobulin (IVIG) and high-dose aspirin. Early initiation of IVIG is crucial for reducing the risk of CAA. For cases that are refractory to initial treatment, corticosteroids or other immunosuppressive agents may be considered.
Treatment and prognosis comparison
| Feature | Pediatric Kawasaki Disease | Adult-Onset Kawasaki Disease |
|---|---|---|
| Incidence | Much more common, peaking in children <5 years. | Rare, accounting for 1–3% of total cases. |
| Common Symptoms | High fever, rash, red eyes, oral changes, extremity changes, lymphadenopathy. | High fever, rash, red eyes, oral changes, extremity changes, more frequent cervical adenopathy, joint pain, hepatitis. |
| Complications | Coronary artery aneurysms in ~25% of untreated cases. Lower risk with IVIG. | Lower incidence of coronary aneurysms (~5%), but risk is higher if diagnosis is delayed. |
| Misdiagnosis Risk | Moderate, often confused with common childhood infections. | High, due to rarity and overlap with other autoimmune and infectious diseases. |
| Treatment Response | High rate of response to IVIG and aspirin if treated early. | Timely IVIG and aspirin are effective, but diagnosis is often delayed. |
| Long-term Management | Lifelong cardiovascular monitoring required for those with persistent coronary abnormalities. | Lifelong cardiovascular monitoring is also necessary, particularly for those with initial or regressed aneurysms. |
Conclusion
While predominantly a pediatric illness, older people can get Kawasaki disease, and its occurrence is a significant medical challenge due to its rarity and atypical presentation. The high frequency of joint pain, hepatitis, and cervical lymphadenopathy in adults, coupled with the low prevalence, makes timely diagnosis difficult and increases the risk of severe coronary artery damage. Early recognition and treatment with intravenous immunoglobulin and aspirin are essential for managing the disease and preventing long-term cardiac complications. Healthcare providers should maintain a high index of suspicion when evaluating older adults with prolonged fever and inflammatory symptoms, especially when common infectious or autoimmune causes have been ruled out. Continuous long-term cardiovascular follow-up is necessary for all individuals who have experienced Kawasaki disease, regardless of age. For more information on adult congenital heart disease and related vasculitides, visit the American Heart Association website.
