differential diagnosis
Last reviewed 01/2018
Discoid eczema is often so circumscribed that it may be difficult to distinguish it from psoriasis and ringworm. Psoriasis does not have vesicles and does not usually itch and ringworm can be confirmed from skin scrapings. Varicose eczema should be considered if venous insufficiency is evident. Patch testing will help identify allergic contact dermatitis, particularly in women with nickel dermatitis and hand lesions with a nummular pattern of dermatitis.
In childhood it is often confused with atopic dermatitis. Unlike atopic dermatitis nummular eczema usually doesn't occur in the first few years of life and it generally doesn't continue beyond puberty in children (1).
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