Nummular Dermatitis (Discoid Dermatitis) By Thomas M Ruenger, MD, PhD, Georg-August University of Göttingen, Germany Reviewed / Revised Jan 2023 View Patient Education Symptoms and Signs Diagnosis Treatment Key Points Topic Resources Nummular Dermatitis Nummular Dermatitis (Hands) Nummular dermatitis is inflammation of the skin characterized by coin-shaped or discoid eczematous lesions.