Mucocutaneous disease: a child with extrapulmonary manifestation of mycoplasma infection.

Mycoplasma-induced rash and mucositis is a distinctive subset of reactive infectious mucocutaneous eruption identified in 2015 to differentiate it from other mucocutaneous disorders such as Stevens-Johnson syndrome, erythema multiforme major, and toxic epidermal necrolysis. Although its pathophysiology is not completely understood, Mycoplasma-induced rash and mucositis is characterized by polyclonal B cell proliferation, production of antibodies against Mycoplasma pneumoniae, subsequent immune complex deposition, and keratinocyte apoptosis. Clinical manifestations include scattered cutaneous lesions and severe mucositis, which predominantly affect children and young males. In this report, we present the case of a 4-year-old boy with characteristic Mycoplasma-induced rash and mucositis symptoms, including erythematous annular lesions, mucosal involvement, and positive serologies for Mycoplasma pneumoniae and herpes simplex. The diagnostic challenges, treatment modalities, and differential diagnosis of erythema multiforme major are discussed. Our case underscores the importance of recognizing Mycoplasma-induced rash and mucositis as a distinct entity, facilitating accurate diagnosis and tailoring management strategies to optimize patient outcomes.