RGD uses the Human Disease Ontology (DO, https://disease-ontology.org/) for disease curation across species. RGD automatically downloads each new release of the ontology on a monthly basis. Some additional terms which are required for RGD's curation purposes but are not currently covered in the official version of DO have been added. As corresponding terms are added to DO, these custom terms are retired and the DO terms substituted in existing annotations and subsequently used for curation.
A disease of the pilosebaceous unit, presenting clinically as grouped follicular papules or plaques with associated hair loss. It is caused by mucinous infiltration of tissues, and usually involving the scalp, face, and neck. It may be primary (idiopathic) or secondary to mycosis fungoides or reticulosis.