This review aims to examine the current concepts of mycoplasmosis, its prevalence, different etiological variants causing damage to various systems and organs, growing resistance of Mycoplasma pneumonia, and prevalent mutations recently known to have been associated with extrarespiratory lesions caused by autoimmune reactions developing in various organs, often without typical symptoms of respiratory tract damage. The most common pathologies include cardiovascular lesions and disorders of the central nervous system, found to be more severe in patients having mixed infections with mycoplasmosis and herpesvirus infections. Children with severe mycoplasmosis often develop skin and mucosal lesions, such as vesicular dermatitis, hemorrhagic vasculitis, urticarial rash, erythema multiforme (EM), Stevens–Johnson syndrome (SJD), and toxic epidermal necrolysis (TEN). We report two cases of Mycoplasma pneumonia-associated pneumonia complicated by SJD in children. We discuss an interdisciplinary problem of optimizing etiopathogenetic therapy for such patients with the consideration of factors triggering the development of skin and mucosal lesions in children with mycoplasmosis alone or in combination with herpesvirus infection.