Abstract
Langerhans cell histiocytosis (LCH) is a rare histiocytic neoplastic disorder that mainly affects the skin and bones, with dermatological manifestations that can be easily confused with other dermatological conditions, such as seborrheic eczema, psoriasis, lesions of herpes simplex virus infection, fungal infection, lichen planus, and cutaneous lymphomas. This case report describes an eight-month-old infant who, at a child health appointment, presented with progressive erythematous papulovesicular lesions, initially treated with hygiene measures (skin hydration and hygiene) and mupirocin ointment, but which persisted and worsened, leading to a skin biopsy. The diagnosis of self-limiting congenital histiocytosis was confirmed, and the child was referred to the Portuguese Oncology Institute. The case highlights the importance of early recognition of LCH, the multidisciplinary approach, and the crucial role of the family doctor in the diagnosis and appropriate management of this rare condition.