Early-onset multisystem Langerhans Cell Histiocytosis with pulmonary and cutaneous involvement in a 3.5-month-old infant: A case report.

Background: Langerhans cell histiocytosis (LCH) is a rare clonal proliferative disorder characterized by the accumulation of Langerhans-type dendritic cells in various tissues, including the lungs and skin [1]. One of the major challenges in this disease is its early diagnosis, the most important reason being that pulmonary involvement is rare in this disease. [2]. Case Presentation: A 3.5-month-old male infant presented to the emergency department of a children's hospital with symptoms of respiratory distress, mild fever, and vesicular-pustular skin lesions. Imaging studies revealed diffuse interstitial lung disease with bronchiectasis and cystic changes. Skin biopsy was positive for immunohistochemical markers CD1a and S-100, confirming the diagnosis of LCH. The patient initially required invasive mechanical ventilation and was subsequently managed with noninvasive mechanical ventilation and systemic corticosteroids, resulting in clinical improvement. Conclusion: Considering the patient presented, attention should be paid to Langerhans Cell Histiocytosis in infants who present with respiratory distress and skin lesions to enable early diagnosis and timely intervention.