Kawasaki Disease (KD) is acute, febrile, multisystem vasculitis of early childhood, the detailed mechanism of which is still unclear. Skin symptoms occur in KD, such as edema of the hands and feet with subsequent desquamation and redness at the inoculation site of bacillus Calmette-Guerin (BCG). The change at the BCG inoculation site has been considered as a specific feature of KD, although its mechanism is not fully understood. We present an 11-month-old boy who developed fever with redness of the BCG site due to infection with human herpes virus type 6 (HHV6). At the age of 3 months, the patient received BCG. His fever remitted 7 days after the onset of skin redness, with sequential desquamation at the BCG site and extremities, which is not a common feature of HHV6 infection that typically lasts for 3 days. The final diagnosis was exanthema subitum. Characteristically, the HHV6 infection in our patient appeared to be associated with the invigoration of the T cell system, as represented by the elevated serum levels of soluble interleukin-2 receptor (3,490 U/ml vs. normal range 145-519 U/ml). This patient clearly showed redness and crusting at the BCG inoculation site, suggesting that HHV6 infection might cause skin changes similar to those of KD via an unknown mechanism. In addition, we suggest that the activation of the T cell system may account for the skin lesions in KD, characterized by redness and subsequent crusting of the BCG inoculation site and desquamation of the extremities. Kawasaki disease (KD) is acute, febrile, multisystem vasculitis of early childhood, the detailed mechanism of which is still unclear. Skin symptoms occur in KD, including polymorphous rash, edema of the hands and feet with subsequent desquamation, and redness and desquamation of the bacillus Calmette-Guerin (BCG) inoculation site. The skin lesions at the BCG inoculation site were reported to be a specific feature of KD, although its mechanism is not fully understood (Sinha and Balakumar 2005;Weinstein 2006).Here, we report a patient with redness of the BCG site with subsequent crusting of the site and desquamation of the extremities in the recovery phase and who was proven serologically to have infection with human herpes virus type 6 (HHV6).
Clinical FindingsAn 11-month-year-old boy developed fever of 38-40°C, without symptoms suggesting an infection focus.His medical and family histories were unremarkable. He received a BCG inoculation at the age of 3 months. There was no cough or throat redness, and was only a non-specific rash. He was referred to our hospital at day 4 because of persistent fever and poor general condition. He was not active in eating. On admission to our hospital, he showed redness at the BCG inoculation site (Fig. 1a), which is regarded as specific to KD (Weinstein 2006). However, his clinical features were far from those of typical KD. There was no non-exudative conjunctivitis, oral findings, extremity changes, or obvious cervical lymphadenopathy. The peripheral blood cell examination showed white blood cel...