nummular dermatitis /num″yələr/ [L, nummuli, petty cash; Gk, derma, skin, itis, inflammation] , a skin disease characterized by coin-shaped, vesicular, or scaling eczema-like lesions, commonly on the forearms and front of the calves. The cause is unknown. Keeping the skin hydrated is important. A health care provider should be consulted as the lesions can be difficult to treat.
