Histiocytosis (Letterer–Siwe) Cutaneous T-cell lymphoma Leukemia and lymphoma Nutritional Acrodermatitis enteropathica Pellagra Kwashiorkor Other Psoriasis Erythroderma a Netherton syndrome Ichthyosis a Potentially acute life-threatening condition Nummular Eczema Nummular eczema presents as coin-shaped plaques that are erythematous and may contain tiny vesicles, crusts, and excoriations Lesions often occur on the hands, arms, and legs ( Fig 65.2 ) They may be single or multiple and are often symmetric Nummular eczema can be related to dry skin and atopy Differential diagnosis includes dermatophyte infection, impetigo, and contact dermatitis (such as nickel in belt buckles or school chairs or desks)