As illustrated by the cases and differential diagnoses in this session, there are many overlapping signs and symptoms caused by many viral and bacterial infections that can complicate the diagnosis of viral infections in pediatrics. In particular, there are a number of dermatologic manifestations to consider. Although there are reports in the literature of rash being linked to influenza in school-aged children, my experience does not reflect this, as I have rarely seen a patient with influenza who has a rash or an exanthem. Thus, for those with suspected influenza infection and a rash, you need to think about other viruses that could co-infect with the influenza or reconsider whether the patient has influenza at all. Possible co-infecting viruses include rhinovirus, enterovirus, adenovirus, and coxsackievirus, and these can co-occur with influenza fairly commonly.

If a patient presents with conjunctivitis and a fever, depending on other aspects of the presentation, you might consider adenovirus infection or possibly Kawasaki disease, incomplete (atypical) Kawasaki disease, or multisystem inflammatory syndrome in children. Multisystem inflammatory syndrome in children mimics Kawasaki disease, atypical Kawasaki disease, and toxic shock syndrome, with maculopapular rash being the most common rash observed. Staphylococcal scalded skin syndrome can sometimes be confused with Stevens-Johnson syndrome (SJS) in the early stages, but children with SJS are really sick and the desquamation pattern is a bit different between these syndromes. You usually only get very superficial mucosal involvement with Staphylococcal scalded skin syndrome, whereas with SJS, which can be linked to viral infections, you can see very deep and very extensive mucosal involvement.

Although data are limited, COVID-19 infection in children can be associated with a rash that looks very similar to that seen with other viruses. A recent national survey in Spain described the clinical presentations of dermatologic manifestations in patients with suspected COVID-19. Mean patient age for the various presentations reflected a primarily adult population overall. Of those cases of COVID-19 that were associated with dermatologic findings, the most common were maculopapular eruptions, occurring in 47% of patients, with a mean age of 55.3 ± 20.2 years. A fairly large percentage of the identified patients (19% of dermatologic cases) reported COVID fingers and toes, which is basically an acral erythema and edema of the toes and hands (pseudo-chilblain). Further, 19% of patients had urticarial lesions and 9% had vesicular-like rashes. There were even necrotic lesions or livedo reported in 6% of patients, mostly seen in older patients with more severe disease. These findings suggest that the most common COVID-related manifestation is a maculopapular rash that is indistinguishable from other maculopapular rashes seen with other viruses. This highlights the importance of viral testing to identify the underlying cause.