What are Nodules?

Nodules - Photo © A.D.A.M.

Nodular Acne.  Photo © A.D.A.M.

Updated April 16, 2014.

Definition: An inflamed acne lesion presenting as a hard, painful lump under the skin. Nodules occur when there is a deep break in the follicle wall and contaminated debris empties into the dermis, infecting adjoining follicles.