Differences and similarities between Monkeypox and Chickenpox in children during an outbreak

Herein, we described cases of children under 16 years old suspected to be infected with Monkeypox virus (MKPV) and diagnosed with chickenpox in public hospitals of Marseille, south of France.

We conducted a retrospective study from March 23rd^, 2022 to October 20th^, 2022 in our institution of results of MKPV DNA and varicella-zoster virus (VZV) DNA detection by PCR performed on cutaneous lesions swabs collected from children <16 years old.

None of the cutaneous swabs collected from 14 children were positive for MKPV DNA. In contrast, 30/168 (17 %) cutaneous swabs collected from children were positive for VZV DNA. Of these 30 VZV-positive children, 7 had been suspected of MKPV infection because of their atypical rash, due to the location of the lesions and the chronology of their appearance.

As in our cohort, pediatric cases of the 2022 Monkeypox outbreak in non-endemic developed countries have been very rare. This variant of MKPV does not normally spread easily and requires very close physical contact between an infected person (skin lesions, bodily fluids or respiratory droplets) and another person to be transmitted. It will nevertheless be a question of remaining vigilant as not to ignore the possibility of close contact or sexual transmission of Monkeypox in a child, or the possibility of a new and more contagious variant.

It is difficult to differentiate Monkeypox infection from other infections associated with rashes, it is important to remember that viruses change as well as their forms of presentation.