Coin shaped eczema is :

A. i.e. Nummular eczema Circular or oval coin shaped lesionsQ are seen in nummular (discoid) eczema. Dermatitis / Eczema Nummular (Discoid) Eczema More frequently a disease of middle aged adult (50-65 years) men. However a second peak around 15-25 years in women and rarely childhood onset (at 5 years age) is also seen. Dry skin in elderly is a contributory factor. Diagnostic lesions is a well demarcated, coin shaped eryrhematous plaqueQ arising, quite rapidly, from the confluence of tiny, closely set, thin walled papules and papulovesicles. Pin point oozing, crusting and scaling eventuate. Pruritis varies from severe (in acute phase) to minimal. Later central clearing (resolution) and peripheral extension leads to annular or ring shaped lesions. Secondary lesions in a mirror-image configuration on opposite side of body and reactivation of apparently dominant lesions (paicularly on premature discontinuation of treatment) is very characteristic. Common locations are trunk or extensor surfaces of extremities, paicularly on the pretibial areas (in men) or dorsal aspects of hands (in women). Differential Diagnosis: Contact dermatitis should be suspected in chronic recalcitrant and unusually severe case where patches are few, asymmetrical and of unusual configuration. Psoriasis has usually more well defined, thickened, scaly and more number of plaques. Bowen's disease usually has 1 or 2 red, scaly patches mostly restricted to light exposed areas. Treatment is similar to that of atopic dermatitis. Contact Dermatitis I. Air borne C.D.Q - Is due to pahenium (congress grass)Q II. Primary irritant C.D - Due to direct contact with toxic irritating materialQ - Palmar surface of handsQ are m.c. involved III. Allergic C.D. - Due to contact with an agent to which delayed hypersensitivity has developed. - Ex-Nickel (m.c.)Q dye, cosmetics, local anesthetic. Seborrheic Dermatitis Occurs on hairy sites, flexures or on central trunk. It is chracterized by: Itching or burning Severe dandruffQ Greasy yellow scalesQ over erythematous patch (stuck on appearance) Cradle capQ is seen in pityriasis capitis complicated by seborrheic dermatitis.