BACKGROUND Erythema multiforme (EM) is a reactive mucocutaneous disorder typically initiated by viral infections. Although the management of EM differs according to the clinical course and trigger factor, it is not clear whether antiviral suppressive therapies may be useful in cases related to such infections. Moreover, the treatment is most often based on supportive care directed towards only the symptoms. OBJECTIVE To present a clinical case of a child in which antimicrobial photodynamic therapy (aPDT) and photobiomodulation therapy (PBMT) were used for orofacial manifestations of EM secondary to viral infections. METHODS A Brazilian 1-year-old boy was admitted to an ICU due to a severe Influenza A H3N2 infection, pneumonia with pleural effusion, and sepsis. About 10 days later, it was noted bleeding lip lesions covered by crusts and bleeding tongue lesions, diagnosed as EM secondary to both H3N2 and herpes simplex virus infections, confirmed by serology tests. A combination of an aPDT session and six PBMT sessions was proposed and resulted in almost complete resolution of the lesion on the 7th day. CONCLUSIONS Given the complexity of the present case, the combination of phototherapies seems to be a promising tool for treating acute orofacial mucosal lesions of viruses-induced EM. More studies, however, are needed to reach a definite conclusion.