Reply to "A look beyond oral lichen planus".

We are honored to have received public comment on our recent paper1 published in this journal, and we would like to answer and clarify the doubts raised by Tomo et al.2 Lichenoid lesions triggered by irritating agents such as restorative materials and medications (nonsteroidal anti-inflammatory drugs, antihypertensives, anticonvulsants, antimalarials, antiretrovirals, oral hypoglycemics, dapsone, gold salts, penicillamine, and phenothiazines) can resemble oral lichen planus (OLP). However, such triggers are rare in children, and the same is true for the patients presented in our work for whom a careful medical history was performed. Tomo et al.2 suggest that in children daily consumption of lollipops could be a possible trigger for the development of lingual lesions. However, in our case series, patients 2, 3, 7, 8, and 9, who presented lesions exclusively on the dorsum of the tongue did not have a history of frequent intake of sweets such as lollipops. We collected historical and clinical data from each patient, and every patient underwent an incisional biopsy of the lesion to confirm a diagnosis with histopathology reported with typical features of OLP: hyperkeratosis and hypergranulosis, acanthosis and papillomatosis, dense band-like inflammatory infiltrate in the superficial dermis, vacuolar degeneration of the epithelial basal cells associated with Civatte bodies. Although biopsy was performed on every patient, for patients 5, 6, 7, 11, and 12, we only had the pathology report available with no specifics of the histology, so we could not provide a detailed report. However, for each individual patient, diagnosis was obtained after an adequate process of exclusion of other pathological entities. Regarding patient number 11, who presented with keratotic papular and erythematous lesions on the buccal mucosae and ventrum of the tongue bilaterally, her general medical and dermatological history was negative. She underwent laboratory tests that showed positive antinuclear antibodies (ANA+), but after an assessment of the immunological status, no other positivity was detected. Clinical findings and histological features confirmed the diagnosis of OLP, and any autoimmune disorder was excluded. According to a Chinese study, specific serum ANAs are present in 28.1% of cases of OLP3 OLP is a chronic inflammatory disorder characterized by apoptosis of epithelial cells triggered by auto-cytotoxic T-lymphocytes4; thus, the presence of autoantibodies indicates the possibility that OLP patients are actually developing an autoimmune state against different targets, which together with the eventual control of symptoms and the possibility of a malignant transformation, represents an additional reason for carrying out periodic follow-up in these patients. Although its exact incidence in the pediatric population is unknown, it is considered a rare event, with a prevalence of <2%–3% of total cases, according to some authors.5 Further studies are necessary to clarify the real prevalence of OLP in the pediatric population and to better understand the clinical and etiopathogenetic characteristics. Conceptualization: Francesca Spirito and Lorenzo Lo Muzio. Validation: Lorenzo Lo Muzio and Eleonora Lo Muzio. Data curation: Giuseppina Campisi, Andrea Santarelli, Lucio Lo Russo, Corrado Rubini, Gianfranco Favia, Luisa Limongelli, Noemi Coppola, and Stefania Leuci. Writing—original draft: Francesca Spirito and Vito Carlo Alberto Caponio. Writing—review and editing: Francesca Spirito and Giuseppina Campisi. Supervision: Stefania Leuci and Eleonora Lo Muzio. All authors have read and agreed to the published version of the manuscript. The authors declare no conflict of interest. Data sharing is not applicable to this article as no new data were created or analyzed in this study.