Kawasaki disease in infants below 6 months: a clinical conundrum?

Abstract

Aim: Kawasaki disease (KD) is a medium vessel vasculitis of childhood. In infancy KD is often characterized by incomplete and atypical forms. There is paucity of literature on KD in children below 6 months and there are no data from any developing country. This study defines the profile of children with KD below 6 months at our centre.Methods: During January 1994 to March 2015, 460 children were diagnosed with KD and 17 (3.6%) were below 6 months. Diagnosis was based on American Heart Association (AHA) criteria. All children were treated with intravenous immunoglobulin and aspirin; three also received infliximab.Results: Mucosal changes were present in 11 patients (64%); extremity changes in 11 (64%); rash in nine (53%); conjunctival injection in eight (47%); and cervical lymphadenopathy in three (17%). Irritability was noted in 15 patients (88%); four (23%) had respiratory symptoms; and two (11%) had bacille Calmette-Guerin scar reactivation. Fifteen (88%) had incomplete KD. Twelve patients were diagnosed beyond day 10 of illness. Thrombocytopenia was seen in four. Coronary artery abnormalities were present in six (35%) patients. Two children died from disease-related complications -one of these had giant coronary artery aneurysms. Conclusion:Our data show that incomplete forms of KD are commonly seen in children below 6 months of age, thereby resulting in delayed diagnoses. Pediatricians need to have a high index of suspicion of KD when dealing with a young infant with unexplained fever beyond 5 days. The AHA criteria appear to be inadequate for diagnosing KD in infants below 6 months.

High Risk of Coronary Artery Aneurysms in Infants Younger than 6 Months of Age with Kawasaki Disease

“…However, as with our study, other recent studies of this young population have also had a high prevalence of CAA including 35% in a study from Chandigarh, India and 30.8% in a study in Anyang, Korea. 1, 7 Also, in our study, infants < 6 months of age were more likely to be of Asian descent. This is consistent with data from Japan where the highest incidence of KD is seen in infants less than a year old.…”

“…1, 7, 14, 15 In our study, the proportion of patients with KD < 6 months old presenting with incomplete KD varied by site. At RCHSD, the prevalence of incomplete KD in infants < 6 months old (37.8%) was similar to those older than 6 months old.…”

“…1-7 These adverse outcomes may be intertwined as incomplete clinical signs can lead to delayed diagnosis, late treatment, and increased risk of aneurysms that develop in up to 25% of untreated or late treated patients with KD. However, limited information is available for this population.…”

Difficult diagnosis of atypical kawasaki disease in an infant younger than six months: a case report

“…Due to the absence of a specific diagnostic test or pathognomonic clinical feature, currently, the diagnosis of KD is still made on clinical criteria [2]. Atypical or incomplete forms of KD are common (15–20% of all patients) especially in children younger than 6 months [3] or older than 5 years, with a higher incidence of coronary artery abnormalities [4, 5], long term consequences [6] and resistance to therapy [7]. Therefore, a high index of suspicion is needed for any infant or child with protracted fever of unknown origin, in order to avoid a missed diagnosis.…”

Kawasaki disease for dermatologists

“…Hence, one should carefully observe and ask for signs and symptoms suggestive of KD that may have already subsided. Incomplete KD is most commonly seen in infants,[60] and is often associated with development of CAAs.…”