A 2-year-old boy is brought to the office by his mother due to a rash that started 3 days ago. A similar red, itchy rash on the cheeks, trunk, and arms has occurred intermittently since infancy. The mother had thought that the rashes were related to the consumption of certain foods, but elimination of cow's milk and fruits did not improve the rash. The patient has had a few upper respiratory infections but no major illnesses. Vaccinations are up to date, and he takes no medications. He attends a day care facility. Vital signs are within normal limits. The rash on the patient's back is shown in the exhibit. Similar findings are observed on the cheeks and proximal upper extremities. The diaper area is clear, and no mucosal lesions are present. This patient's current condition increases his risk of developing which of the following additional disorders?
Atopic dermatitis | |
Pathogenesis |
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Clinical |
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Associated |
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Laboratory |
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Th2 = T-helper cell type 2. | |
Atopic dermatitis (AD), or eczema, is a chronic inflammatory skin disorder common in children. The disease typically occurs at age <5, with many patients developing symptoms in infancy. AD typically presents as erythematous papules and plaques involving the face, scalp, trunk, and extensor surfaces. The diaper area is usually spared. In older children and adults, it often manifests as lichenification in a flexural distribution (eg, neck, wrists, antecubital and popliteal fossae). Eczema has a chronic course marked by exacerbations and remissions, and its severity tends to lessen with age. Intense pruritus is a hallmark of AD.
AD can be associated with mutations affecting epidermal barrier proteins such as filaggrin, resulting in impaired skin barrier function. This increases immunologic exposure to environmental allergens and microbial antigens, leading to immune hypersensitivity. Affected patients usually have high serum IgE levels and peripheral eosinophilia. Children with AD often have a family history of atopy and are at risk of developing other atopic diseases, such as allergic rhinitis and asthma (allergic triad).
(Choice A) Celiac disease is associated with dermatitis herpetiformis, which presents with pruritic vesicles and plaques on the buttocks and extensor surfaces of the extremities. In addition, this skin disorder is extremely uncommon in children.
(Choice C) Langerhans cell histiocytosis is a dendritic cell disorder that can present in infancy or early childhood with a severe, refractory, erythematous or ulcerative rash on the scalp, trunk, or groin. This patient's rash flares and resolves without intervention.
(Choice D) Psoriatic arthritis is associated with psoriasis. Manifestations of psoriasis include erythematous, well-demarcated papules and plaques with a silvery scale, which are not seen in this patient.
(Choice E) Ulcerative colitis, a type of inflammatory bowel disease, can be associated with dermatologic manifestations, such as pyoderma gangrenosum (ulcerative rash) or erythema nodosum (painful raised red nodules). Both are uncommon in children, and neither is seen in this case.
Educational objective:
Atopic dermatitis (eczema) is a common, chronic inflammatory disorder caused by impairment of the skin's barrier function. Eczema presents with pruritus and erythematous papules and plaques and is associated with other atopic diseases, such as allergic rhinitis and asthma.