Definition
A papule is a solid or cystic raised spot on the skin that is less than 1 centimeter (cm) wide. It is a type of skin lesion.
References
Gawkrodger DJ, Ardern-Jones MR. Terminology of skin lesions. In: Gawkrodger DJ, Ardern-Jones MR, eds. Dermatology: An Illustrated Colour Text. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 7.
James WD, Elston DM, Treat JR, Rosenbach MA, Neuhaus IM. Cutaneous signs and diagnosis. In: James WD, Elston DM, Treat JR, Rosenbach MA, Neuhaus IM, eds. Andrews' Diseases of the Skin: Clinical Dermatology. 13th ed. Philadelphia, PA: Elsevier; 2020:chap 2.