Additional InformationHashimoto-Pritzker histiocytosis (HPH) is a variant of LangerhansCell histiocytosis(see this term) characterized by multiple disseminated Skin lesions (firm, red-brown, painless papulo-nodules). Less than 50 cases reported so far, with onset at Birth or during the neonatal period. The Skin lesions may affect the entire body, or may manifest on palms and soles or Head and Scalp only. Usually, HPH does not involve the internal organs. Single cases with involvement of Bone marrow, bone, Lung and Eye have been documented. HPH has a spontaneous regression within 1 to 3 months. Etiology remains unknown.