Toxic shock syndrome is a multi-system disorder that involves multiple organs. The disease is uncommon in children but sometimes is occurred following staphylococcal infections. This disease was rarely reported following influenza infections (
1,
7,
8) and after searching the related literature, our case is the first reported pediatric case. Although in this case the coinfection of influenza and staphylococci infection was not ruled out.
During the influenza epidemic, its diagnosis in young children can be made based on the clinical symptoms (
1). Our patient was admitted 5 days after onset of typical clinical features of influenza during the flu epidemic. Positive results of PCR for influenza decrease after the first 72 hours, (
4) therefore, we did not send samples for PCR detection. For detection of toxic shock syndrome, there is not any specific tests, and the diagnosis is based on clinical and laboratory criteria (
1,
4). Blood cultures are less helpful. Therefore, early detection and treatment of the disease is very important because delay in treatment leads to increased mortality and morbidity. The ESR (erythrocyte sedimentation rate) and CRP (C-reactive protein) levels were not very high and we excluded Kawasaki disease due to the absence of typical and atypical KD criteria and presence of hypotension and rapidly progressive illness, so we did not performed echocardiography. Most cases reported the toxic shock syndrome as a secondary disease of influenza, were followed by upper and lower respiratory tract
Staphylococcus aureus infections (tracheaitis, sinusitis, pneumonia) (
7,
8) which is usually associated with persistent fever and worsening of illness. TSS also can occur without any identifiable focus of infection (
4). If the flu worsens, a secondary infection as a complication of the disease should be considered (
1). Although most cases of secondary infections are due to pneumococcus, in more severe cases staphylococcus plays an important role (
5). Our patient did not have any underlying immunodeficiency pathology, like other cases of toxic shock syndrome following influenza infections (
7,
8) and, like most of the reported cases, had not received influenza vaccine. As a result, influenza vaccination, particularly in young children can strongly reduce most of the secondary bacterial infections and is highly recommended (
1,
4,
5).