In parts 1 and 2 of this series on atopic dermatitis (AD),1,2 the current putative pathogenesis, scoring systems for severity grading, and epidemiology were reviewed. Part 3 reviews the differential diagnosis, with an emphasis on the difficulty of differentiation from some rare but notable illnesses, as well as the recently expanding data on comorbidities that identify AD as a multisystem disorder with widespread health implications for the patient.
The differential diagnosis for pediatric AD includes chronic dermatoses (eg, seborrheic dermatitis, psoriasis), congenital disorders (eg, Netherton syndrome), malignant diseases (eg, cutaneous T-cell lymphoma [CTCL]), immunodeficiencies, infections, and metabolic disorders.3 Netherton syndrome must be ruled out to prevent extensive drug absorption when treating with topical calcineurin inhibitors (TCIs).4 Due to the presence of bamboo hairs in these patients, a hair mount may aid in the diagnosis of Netherton syndrome. Misdiagnosis of CTCL as AD may complicate the analysis of safety data on TCIs.4,5 Multiple skin biopsies are essential in cases of suspected CTCL to provide an accurate diagnosis. Biopsy can be considered in AD cases with changing and/or unusual morphology, erythrodermic skin changes, and disease that is poorly responsive to multiple therapeutic modalities.
Pediatric AD often takes a psychological toll on patients as well as household members. Almost half of children with AD are reported to have a severely impaired quality of life (QOL).6 Contributing factors include fatigue, sleep disturbance, activity restriction (eg, inability to participate in sports), and depression.7
Chamlin et al8 developed the Childhood Atopic Dermatitis Impact Scale (CADIS), a 45-item instrument (refined from a 62-item prototype), to measure QOL in young children with AD and their family members. Responses were evaluated with consideration of 5 domains: symptoms and activity limitations/behaviors in children, as well as family/social function, sleep, and emotions in parents. The top 12 factors that parents found most bothersome about AD included itching/scratching, child’s pain/discomfort, sleep issues, embarrassment or worry about appearance, child’s fussiness/irritability/crying/unhappiness, helplessness/can’t control it/predict it, worry about skin infection, dryness of skin/nonsmooth skin, skin bleeding, worry about damage/scars, stares/comments of strangers and other children, and rashes/redness of skin/discoloration. Parents were asked to respond to items about their emotional health and social functioning, such as “My child’s skin condition has strained my relationship with my spouse or partner,” “My child’s skin condition makes me feel sad or depressed,” and “I am bothered by the reaction of strangers to this skin condition.”8
Kiebert et al9 found that AD patients had lower scores on the Short Form-36 Health Survey’s vitality, social functioning, and mental health subscales compared to individuals in the general population. The authors noted that anxiety in AD patients is of particular concern, as stress has been found to trigger the itch-scratch cycle, potentially setting off AD flare-ups.9 Family impact of AD is aggravated by disease severity. Sleeplessness, relationship stress, and time management can all cause family problems in patients with AD.8
In a survey of 3775 older teenagers aged 18 to 19 years (80% response rate out of 4774 prospective participants), 9.7% of participants reported having current AD.10 Suicidal ideation was higher in those with current AD than those without AD (15.5% vs 9.1%). The prevalence of suicidal ideation rose to 23.8% in those with both AD and itch. Diagnosis of AD (as determined through participant responses to the question, ‘‘Do you have, or have you had eczema?’’) was associated with mental health problems in 16.0% of those with AD compared to 10.1% of those without AD, with an especially reduced likelihood of romantic relationships for adolescent boys with AD, as measured using the Strength and Difficulties Questionnaire, which measures 4 problem domains and assesses presence of mental health issues in the past 6 months, and the Hopkins Symptom Checklist 10, which uses 10 questions to measure anxiety and depression symptoms in the past week.10
Dalgard et al11 assessed whether the psychological burden of AD persists in adulthood in an international, multicenter, observational, cross-sectional study conducted in 13 European countries. Each dermatology clinic recruited 250 consecutive adult outpatients to complete a questionnaire along with a control group of 125 hospital employees without skin disease from the same institution but from different departments. The study included a total of 4994 participants (3635 patients and 1359 controls). Clinical depression and anxiety were present in 10.1% and 17.6% of patients, respectively, versus 4.3% and 11.1% of controls, respectively. The prevalence of depression and anxiety was highest in patients with leg ulcers, hand eczema, psoriasis, and AD.11 This study demonstrated that the psychological comorbidities of childhood conditions such as AD may persist into adulthood.
