Coin shaped eczema is-

nummular or discoid eczema(coin shaped dermatitis) characterised by round eczematous lesions,papulovesicular and oozing or scaly and erythematous, witha clearly demarcated edge usually on the extensors of the limbs. it is associated with atopic dermatitis,allergic contact dermatitis and asteatotic eczema. clinical features: 1. mild to moderate itching 2.erythematous edematous papules or vescicles that coalese to form round lesions. 3. symetrically distroibuted over dorsum of hands feeet legs and arms. treatment topical steroids antihistamines IADVL textbook of dermatology , eczema page 502