Adult-onset of Langerhans cell histiocytosis: a clinical case

Langerhans cell histiocytosis is mainly diagnosed in children, and its manifestation in adult age is quite uncommon. Skin rashes may be non-specific and mimic a number of dermatoses. Therefore, the clinical diagnosis is challenging and as a rule, such patients are misinterpreted and managed for other disorders by a dermatologist for some years. We present a clinical case of Langerhans cell histiocytosis with skin involvement in a 35-year female patient, who had been treated by a dermatologist for 2 years for pyoderma, seborrheic dermatitis, and skin fold candidiasis. Taking into account the clinical signs and symptoms and age of manifestation, we initially suspected familial benign pemphigus (Hailey-Hailey disease) or follicular dyskeratosis (Darier's disease). However, the histological assessment showed Langerhans cell histiocytosis confirmed by immunohistochemistry with anti-langerin, anti-CD1a, and anti-protein S-100 antibodies. The patient was referred to a hematologist for further work-upand specific treatment. In cases of any treatment resistant disorders, which do not respond to long-term conventional treatment, it is necessary to reconsider the diagnosis by means of histological investigation. It would allow for identification of a disease, which is uncommon in dermatology practice.