It can appear as a single lesion in an organ, up to a large quantity of lesions in one organ. When multiple lesions are scattered throughout an organ, it can be called a multifocal unisystem variety. When found in the lungs, it should be distinguished from Pulmonary Langerhans cell hystiocytosis—a special category of disease most commonly seen in adult smokers. When found in the skin it is called cutaneous single system Langerhans cell LCH. This version can heal without therapy in some rare cases. This primary bone involvement helps to differentiate eosinophilic granuloma from other forms of Langerhans Cell Histiocytosis (Letterer-Siwe or Hand-Schüller-Christian variant). Multifocal unisystem
Seen mostly in children, multifocal unisystem LCH is characterized by fever, bone lesions and diffuse eruptions, usually on the scalp and in the ear canals. 50% of cases involve the pituitary stalk, often leading to diabetes insipidus. The triad of diabetes insipidus, exophthalmos, and lytic bone lesions is known as the Hand-Schüller-Christian triad. Peak onset is 2–10 years of age. Multifocal multisystem
Multifocal multisystem LCH, also called Letterer-Siwe disease, is an often rapidly progressing disease in which Langerhans Cell cells proliferate in many tissues. It is mostly seen in children under age 2, and the prognosis is poor: even with aggressive chemotherapy, the five-year survival is only 50%. Pulmonary Langerhans cell histiocytosis (PLCH)
Pulmonary Langerhans cell histiocytosis (PLCH) is a unique form of LCH in that it occurs almost exclusively in cigarette smokers. It is now considered a form of smoking-related interstitial lung disease.
Infantilism may refer to:

In psychologyParaphilic infantilism, a paraphilia involving the desire to wear diapers and/or fantasies of a return to infancy
Psychosexual infantilism, a concept in psychosexual development introduced by Sigmund Freud
In a more general sense and in colloquial expressions – childlike behavior in adults, particularly lack of judgement and poor ability to make conclusions based on logical reasoning as well as actions driven more by immediate impressions and impulses rather than by rationale. Depending on degree of expression can range from mental disorder, to behavioral disorder or simply psychological makeup and personality trait of otherwise healthy person.In medicineInfantilism (physiological disorder) obsolete use of the term for some developmental disorders and disabilities
Infantilism, also known as infantile speech, a speech disorder in which early speech stages persist beyond the age they are normally expected to fade
Hypothalamic infantilism-obesity, or sexual infantilism, synonyms for adiposogenital dystrophy

See also
Delayed puberty, delayed sexual development symptomatic of several medical syndromes
Diaper fetishism, a paraphilic attraction to wearing diapers which does not involve fantasies of childlike behavior
Paternalism, deliberate limiting of the autonomy of others