Atopic dermatitis in Child
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, and torso. In children and adults, the disease usually involves chiefly the flexural aspects of extremities, but it may be more generalized. Children of African descent may present with an infantile distribution of lesions even later in childhood. Follicular patterns (ie, follicular eczema) are more common in darker skin phototypes. A lichen planus-like appearance has also been reported in persons with darker skin phototypes, due to lichenification and the difficulties in perceiving erythema in darker skin.
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 increases transepidermal water loss and the risk of bacterial and viral cutaneous infections. Patients with atopic dermatitis are prone to impetiginization with Staphylococcus aureus. Secondary infections with herpes simplex virus (eczema herpeticum), molluscum contagiosum, Coxsackie virus, or vaccinia virus (eczema vaccinatum) can 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. Mild cases may improve in adulthood, although some may retain stigmata of dry or sensitive skin.
For more information, see OMIM.
L20.9 – Atopic dermatitis, unspecified
24079001 – Atopic dermatitis
- Pityriasis rosea
- Lichen simplex chronicus is composed of isolated hyperpigmented, leathery plaques, frequently seen on the posterior neck, genitals, and extensor forearms and lower legs. Xerosis and atopy may be exacerbating factors in this condition.
- Nummular dermatitis (nummular eczema)
- The impaired cutaneous barrier in patients with atopic dermatitis makes them more prone to both irritant and allergic contact dermatitis.
- Molluscum contagiosum infections may flare atopic dermatitis in patients prone to eczema and present as numerous flesh to pink-colored dome-shaped papules, often on flank or flexural creases. Molluscum can trigger an eczematous dermatitis in children who have no history of atopic dermatitis. Allergic contact dermatitis is also frequently encountered in atopic patients.
- 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.
- Scaly plaques 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 young children not yet potty-trained, groin psoriasis may present as well-demarcated pink plaques.
- Seborrheic dermatitis tends to involve the scalp and groin in infants and has greasy scale as opposed to dry scale seen in atopic dermatitis. In teenagers, facial seborrheic dermatitis may present as yellow-white scale overlying the eyebrows and glabella or medial cheeks.
- An atopic-like eczematous dermatitis may be observed in patients with Wiskott-Aldrich syndrome, selective IgA deficiency, Letterer-Siwe disease, hyper-IgE syndrome, and Netherton syndrome, as these conditions may display similar eruptions.