A Severe Case of Post-COVID-19 Reactive Infectious Mucocutaneous Eruption in a Pediatric Patient

To the Editors: Mucosal manifestations of COVID-19 have been described with different presentations in both adults and children.1,2 Reactive infectious mucocutaneous eruption (RIME) is a recently proposed term used to describe postinfectious mucositis cases, that is generally preceded by flulike symptoms.3 It is considered a distinct entity from similar conditions such as Stevens-Johnson syndrome since it has predominant mucosal involvement rather than skin manifestations, and the course is often milder.4RIME has been most commonly reported with Chlamydophila pneumoniae, Metapneumovirus, Parainfluenza, Rhinovirus, Enterovirus, and Influenza infections. Recently, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has also been reported as a trigger and, in this case, the mucocutaneous lesions may occur 4 days to 12 weeks after COVID-19 infection symptoms.5 A 17-year-old, previously healthy male, presented to the pediatric emergency department with a 5-day history of diffuse oral ulcerations, swallowing and feeding difficulties, and a 3-day low fever history. He reported no other cutaneous lesions, eye discharge, shortness of breath, chest pain, or gastrointestinal symptoms nor a history of caustic ingestion or trauma. The patient had been diagnosed with coronavirus disease 2019 (COVID-19) in the previous week. On the second day of disease, he was admitted to the emergency department where a laboratory workout was performed, presenting with a hemoglobin of 14.8 g/dL, leukocyte count of 13600/L, normal liver and renal function and a c-reactive protein (CRP) of 23.10 mg/L. At this point, the diagnosis of Lichen Planus was suggested, and he was discharged with a topical corticosteroid (that the patient did not apply) and topical nystatin. Due to the worsening of the symptoms, the patient presented to our pediatric emergency department two days later with scattered ulcerated lesions on the oral mucosa (lips, vestibule, palate, floor, tonsil pillars), partially covered by a fibrin layer and painful lesions on palpation (Fig. 1). He also presented a soft, pitting, and painless lower lip nodular swelling, compatible with a mucocele, and multiple infracentimetric and mobile cervical painful adenopathy’s. His vital signs were normal.FIGURE 1.: Scattered ulcerated lesions on the oral mucosa, partially covered by a fibrin layer and lip mucocele in a pediatric patient with severe mucositis.At this point, a post-COVID-19 infectious severe mucositis diagnosis with signs of probable bacterial coinfection was considered. To exclude herpetic infection, a herpes simplex type 1 and 2 seric polymerase chain reaction (PCR) was performed. Due to over-infection signs, to prevent any further complications and to accelerate healing, an antibiotic course (oral Amoxicillin and clavulanate acid 45mg/kg/day), topical steroids, and oral valacyclovir (20mg/kg/dose) were prescribed, the latter being suspended after confirmation of negative herpes simplex PCR. Supportive and pain control care were also instituted. The patient showed complete resolution of the lesions and did not return to the emergency department. RIME is a rare condition, and, despite presenting an overall good prognosis, its acute onset can lead to very painful and disabling mucositis that may require supportive care and pain control, in addition to more specific treatments.5 Mucositis’ differential diagnosis may be challenging, and RIME can be secondary to diverse infectious agents. Although there are few reported cases of RIME in literature, it is known to be more frequent in adolescents. In this report, we present a RIME case due to COVID-19 in a pediatric patient, who presented with painful diffuse oral ulcerations. From a pediatrician’s perspective, it is crucial to consider RIME in the differential diagnosis of an adolescent patient with postinfectious mucositis.