A 2-year-old child comes with discharge, seborrheic dermatitis, polyuria and hepatosplenomegaly. Which of the following is the most likely diagnosis ?

Ans. is `c' i.e., Lagherhan's cell histocytosis o Seborrhic dermatitis, polyuria, hepatosplenomegaly and discharge suggests the diagnosis of Langerhan's cell histiocytosis. Clinical manifestations of langerhans cell histiocytosis o It has diverse clinical features. These are 1. Skeletal involvement It is seen in 80% of cases (75% cases present with solitary lytic lesion) Skull is the most common site of involvement (Presents with solitary lytic lesion) Involvement of spine leads to collapse of veebral body and compression of spinal cord. In flat long bones the lesion is osteolytic Involement of mastoid bones leads to chronically infected ears. 2. Skin involement It is seen in 50% of patients. It usually manifests as seborrhic dermatitis of scalp or diaper region. 3. Hepatosplenomegaly - a Seen in 20% of patients q Manifests as jaundice and ascites. Localized or disseminated lymphadenopathy Exophthalmos - It is often B/L and is caused by retrorbital accumulation of granulomatous tissue. 6. Pulmonary infiltrates - Seen in 10-15% of patients The lesion consists of nodular infiltrates or diffitse fibrosis. 7. Endocrine Tlypopituitarism, Hypothyroidism, Diabetes insipidus Systemic manifestations - Usually seen in patients affected severly These include fever, weight loss, malaise, irritability o Remember these two uncommon but serious manifestations of LCH 1. Cirrhosis d/t hepatic involvement 2. Ataxia and dysahria d/t CNS involvement