Generalized eruptive histiocytosis in Adult
In a review of 25 cases of GEH, the mean age of onset for adults was 54 years, with onset ages ranging from 23-84 years. The mean age of onset for children was 4 years, with onset ages ranging from 10 months to 10 years. Males represented 57% of all cases that were reviewed.
The etiology of GEH is unknown. There are reports of GEH transforming into another subtype of non-LCH, such as xanthoma disseminatum, raising the question of whether GEH is actually an early phase of a more mature non-LCH.
GEH has been rarely reported to be associated with malignant hematologic disorders of myeloid lineages. As such, it is important to thoroughly screen GEH patients for associated hematologic malignancies.
D76.3 – Other histiocytosis syndromes
110980006 – Generalized eruptive histiocytoma
Differential Diagnosis & Pitfalls
- Urticaria pigmentosa – Lesions are often pruritic and can develop a wheal and flare when scratched or rubbed (Darier's sign).
- Juvenile xanthogranuloma – Typically occurs within the first year of life. Histology demonstrates foam cells and Touton cells in mature lesions.
- Xanthoma disseminatum – Papules may be grouped and favor intertriginous and flexural areas. Transitory diabetes insipidus and mucosal lesions are present in nearly 50% of cases. Histology demonstrates foam cells, Touton cells, and potentially siderosis in mature lesions.
- Benign cephalic histiocytosis – Affects children, with lesions developing first on the head with potential to evolve and involve the neck, upper trunk, and other parts of the body.
- Multicentric reticulocytosis – Papules frequently occur on the acral regions and are associated with arthropathy.