A 14-month-old boy presented to the HUCA with desquamative skin lesions on the scalp and exudative lesions in the folds and perianal region.
A skin biopsy was performed and the diagnosis was LCH. The condition was limited to the skin only and topical treatment was carried out locally.
On further examination, localised gingivitis was diagnosed at the level of 83.84.

In order to determine if there was a relationship with the previous skin process, the corresponding biopsy of the marginal gum of 84 was carried out with processing of the sample with haematoxylin-eosin, according to standard technique, for histopathological study.
At the same time, an immunohistochemical study is carried out using CD1a markers (surface antigen) and S-100 protein specific to Langerhans cells.
The result of the anatomopathological study determined the presence of a squamous epithelium with an infiltrate of polynuclear cells and eosinophils. At the level of the chorion, nodules composed of cells of histiocytic structure with vesicular, clear, dented nuclei, some with an irregular "coffee bean" shape, were evident.

Immunohistochemistry showed evidence of positivity for CD1a surface antigen and S-100 protein, effectively determining the oral involvement of the disease.

The patient was classified within the pathology type of multifocal Langerhans cell histiocytosis.