<unk>  usually affects children between 1 and 15 years old, with a peak incidence between 5 and 10 years of age. Among children under the age of 10, yearly incidence is thought to be 1 in 200,000; and in adults even rarer, in about 1 in 560,000. It has been reported in elderly but is vanishingly rare. It is most prevalent in Caucasians, and affects males twice as often as females. In other populations too the prevalence in males is slightly more than in females.<unk>  is usually a sporadic and non-hereditary condition but familial clustering has been noted in limited number of cases. Hashimoto-Pritzker disease is a congenital self-healing variant of Hand-Schüller-Christian disease.
Langerhans cell histiocytosis
X-type histiocytosis
Sea-blue histiocytosis
Malignant histiocytosis
Crystal-storing histiocytosis
Non-X histiocytosis
Progressive nodular histiocytosis
Langerhans cell sarcoma