TABLE 65.1 DIFFERENTIAL DIAGNOSIS OF ECZEMATOUS RASH Allergy Atopic dermatitis Allergic contact dermatitis Autoeczematization Drug reaction Photoallergic reaction Irritant Irritant contact dermatitis Lichen simplex chronicus Nummular eczema Asteatotic eczema Dyshidrotic eczema (pompholyx) Intertrigo Frictional lichenoid dermatitis Immunologic Wiskott–Aldrich syndrome Hyperimmunoglobulin E syndrome Omenn syndrome Severe combined immunodeficiency Graft-versus-host disease Agammaglobulinemia Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) Infectious Seborrheic dermatitis Dermatophyte infection Scabies Molluscum contagiosum Pityriasis rosea Human immunodeficiency virus Oncologic 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) TABLE 65.2 AMERICAN ACADEMY OF DERMATOLOGY CONSENSUS CONFERENCE FEATURES OF ATOPIC DERMATITIS Essential features (must be present) Pruritus Eczematous skin changes with chronic or recurring history, typical morphology, and distribution • Face, neck, extensor involvement in infants and children • Flexural lesions in any age group • Sparing of groin and axillary regions Important features (seen in most cases, support the diagnosis) Early age at diagnosis Personal or family history of atopy Immunoglobulin E reactivity Associated features Atypical vascular responses (e.g., facial pallor, white dermographism, delayed blanch response) Keratosis pilaris/hyperlinear palms/ichthyosis/pityriasis alba Ocular/periorbital changes Other regional findings (e.g., perioral changes/periauricular lesions) Perifollicular accentuation/lichenification/prurigo lesions Adapted from Eichenfield LF, Hanifin JM, Luger TA, et al Consensus conference on pediatric atopic dermatitis J Am Acad Dermatol 2003;49(6):1088–1095 Copyright © 2003 with permission from the American Academy of Dermatology Acute management of nummular eczema involves ruling out any coexistent superinfection with a bacterial culture from any eroded, crusted, pustular, or painful lesions, and treatment with potent topical steroids Maintenance strategies include using daily petrolatum-based barrier ointments and intermittent potent topical steroid use (e.g., twice weekly) for prevention ... accentuation/lichenification/prurigo lesions Adapted from Eichenfield LF, Hanifin JM, Luger TA, et al Consensus conference on pediatric atopic dermatitis J Am Acad Dermatol 2003;49(6):1088–1095 Copyright © 2003 with permission