Atopic dermatitis in Infant/Neonate
Infants and children are most often affected, with 85% of cases appearing in the first year of life, and 95% of cases appearing by 5 years. Uncommonly, the condition may persist into, or even arise in, adulthood. Less than 1% of adults are affected by atopic dermatitis.
In infants, the disease involves primarily the face, scalp, torso, and extensor aspects of extremities. In children and adults, the disease usually involves chiefly the flexural aspects of extremities, but it may be more generalized. In adults, flexural skin may be clear, and disease may be focal or widespread. Follicular patterns of atopic dermatitis (ie, follicular eczema) are more common in persons with darker skin phototypes.
Atopic dermatitis may be categorized as follows:
- Acute – erythema, vesicles, bullae, weeping, crusting
- Subacute – scaly plaques, papules, round erosions, crusts
- Chronic eczema – lichenification, scaling, hyper- and hypopigmentation
Intense pruritus is a hallmark of atopic dermatitis. Scratching leads to lichenification (skin thickening). Impaired barrier function results in increased transepidermal water loss and susceptibility to secondary bacterial and viral infections. Patients with atopic dermatitis are prone to impetiginization with Staphylococcus aureus. Secondary infections with herpes simplex virus (eczema herpeticum), Coxsackie viruses (eczema coxsackium), vaccinia virus (eczema vaccinatum), or molluscum contagiosum may occur.
Atopic dermatitis is increasing in the developed world. In the United States, about 10% of children may be affected by atopic dermatitis, but the majority of these cases are mild.
For more information, see OMIM.
L20.9 – Atopic dermatitis, unspecified
24079001 – Atopic dermatitis
- Infantile seborrheic dermatitis tends to involve the scalp and groin and has greasy scale as opposed to dry scale seen in atopic dermatitis. Infants with atopic dermatitis often have seborrheic dermatitis as well, and there can be overlap between the conditions.
- The impaired cutaneous barrier in patients with atopic dermatitis makes them more prone to irritant contact dermatitis. Allergic contact dermatitis is also frequently encountered in atopic patients.
- Langerhans cell histiocytosis presents as petechial, eroded papules of the scalp, axilla, hands, feet, or groin with associated lymphadenopathy.
- Scabies is also intensely pruritic, classically accentuated at night. Typical sites of involvement include the interdigital web spaces, axillae, wrists, belt area, buttocks, and feet. The pathognomic sign is the burrow. In young children, scabies may present as widespread, pruritic, crusted vesicopustules.
- Lesions in tinea corporis are typically annular or arcuate. Tinea incognito may be mistaken for atopic dermatitis due to absence of scale and inflammation. Fungal elements can be demonstrated using a potassium hydroxide (KOH) preparation.
- Classic lesions in psoriasis are well-defined erythematous plaques involving the scalp and extensor elbows and knees with overlying silvery scale. In infants and toddlers, psoriasis often presents as well-dermarcated, pink plaques in the groin that involve the intertriginous folds. Groin psoriasis in young children typically improves once the child is potty-trained.
- An atopic-like eczematous dermatitis may be observed in patients with genetic immunodeficiencies (eg, Wiskott-Aldrich syndrome, hyperimmunoglobulinemia E syndrome, selective IgA deficiency, Omenn syndrome), often associated with failure to thrive, recurrent infections, hematologic abnormalities, and chronic diarrhea.
- Disorders of keratinization (eg, nonbullous congenital ichthyosiform erythroderma, Netherton syndrome) may appear similar but present at birth rather than 3-6 months of age.
- Nutritional deficiencies (eg, phenylketonuria, multiple carboxylase deficiency, zinc deficiency, essential fatty acid deficiency) may appear identical to atopic dermatitis but are usually associated with failure to thrive and systemic symptoms.