In a systematic review of the literature and a separate meta-analysis, Legendre et al12 identified a slight increase in lymphoma among AD patients, with an uncertain but potential increase associated with topical corticosteroid application. This finding is similar to trends seen in other systemic inflammatory conditions that involve the skin, such as psoriasis, and is felt to relate to long-term inflammation.
Obesity has been associated with a greater risk for moderate to severe AD in children.13,14
Children with AD are at a higher risk for cutaneous infections and generalization of these infections. The leading infections would be with Staphylococcus aureus, but group A streptococci infections do occur. Herpes simplex virus, vaccinia virus or Kaposi varicelliform eruption (KVE), molluscum with or without dermatitis, and fungal infections occur less commonly but with greater morbidity, largely due to the impaired barrier and some innate reduction in cutaneous immunity.15
Atopic dermatitis in children also is associated with a higher prevalence of extracutaneous infections such as influenza, pneumonia, urinary tract infections, varicella-zoster virus, recurrent ear infections, sinus infections, sore throat, and head or chest colds.16 Children with AD and warts (human papillomavirus infection) have an even greater risk for these comorbidities.17 Warts and molluscum infections may become more extensive in children with AD.18 Generalization of herpetic infections occurs more easily in AD patients due to the impaired skin barrier, which includes generalized skin surface extension of herpes simplex virus type 1, varicella-zoster virus, and historically smallpox. A similar clinical appearance of generalized vesiculopustular lesions with fever can be seen when coxsackievirus A6 infections occur in AD patients; these conditions are called eczema herpeticum due to herpes simplex virus, KVE due to varicella-zoster virus and smallpox, and eczema coxsackium due to coxsackievirus A6,19 though some authors refer to all of these as KVE.20 These generalized viral illnesses overlying AD often result in fever, malaise, pain, and life-threatening skin denudation with risk for dehydration and superinfection with S aureus.7,18 It has been shown that the occurrence of eczema herpeticum in AD is associated with and may be caused by an inability to induce human β-defensin 2 and 3 as well as cathelicidin.21
Staphylococcus aureus colonization has been noted in 90% to 100% of AD cases, which can be associated with a higher eczema area and severity index score.22-24 The role of S aureus in AD includes flare triggering through release of superantigens, leading to IL-31–induced pruritis.25 Recurrent infection with either methicillin-sensitive or methicillin-resistant S aureus has been noted in AD.18,26 Skin infections also occur in AD and appear as erosions and pustules, and coinfection with Streptococcus and Staphylococcus does occur; therefore, cultures often are needed to determine the type of bacteria present on the skin in severe cases and when infection is suspected.27 Perianal bacterial dermatitis is a variant of infected AD occurring in the anal/groin area that is associated with S aureus and/or streptococcal superinfection in which topical corticosteroids and topical anti-infectives can be used. In some severe cases, oral antibiotics may be needed.28
Children aged 0 to 5 years with AD carry an increased risk for injuries requiring medical attention, with association in part due to attention deficit disorder, depression, and anxiety. Antihistamines are believed to aggravate this issue by promoting daytime somnolence29; however, pruritus-induced sleep disturbances in AD also may be responsible for daytime somnolence.30
Children with AD may become sensitized to environmental allergens through delayed-type hypersensitivity. The presumed mechanism is that these agents include ingredients added into applied medicaments and application occurs over an impaired skin barrier allowing for absorption and greater risk of antigen presentation. Approximately 50% of children with difficult-to-control AD will react to 1 or more epicutaneous allergens, and patch testing can be performed to identify relevant allergens that can improve skin severity.7 Severe dermatitis and id generalized hypersensitivity reactions in patients with AD and nickel allergic contact dermatitis have been described and may aggravate underlying AD.31
Parents or caregivers of children with moderate and severe AD spend nearly 3 hours a day caring for their child’s skin and experience QOL impairments including lack of sleep and/or privacy, often due to cosleeping; treatment-related financial expenditures; and feelings of hopelessness, guilt, and depression.7
Steroid phobia is the fear of topical application of corticosteroids resulting in systemic side effects including unrealistic fears (eg, fear that the child will develop muscles such as an anabolic steroid user) as well as realistic but statistically low-risk fears (eg, fear of systemic absorption). These fears often result in underutilization of prescribed topical corticosteroid therapies and undertreatment of children with AD.32,33
