Residents’ Corner
Influence of Diet in Acne Vulgaris and Atopic Dermatitis
Diet has been considered as an influence in dermatology for several years. Unfortunately, although correlation has been breached, causation is yet...
Topical Medication
Children have a relatively higher body surface area–to-weight ratio, allowing for greater potential absorption of topical medicaments and potential side effects from absorption. Types of vehicle, cost, site of application, and availability may impact patient and physician preference in choice of therapeutic topical agent.14
Topical Corticosteroids
Topical corticosteroids (TCs) are the mainstay of treatment for AD and have been used for more than 60 years.14,20 Topical corticosteroids provide anti-inflammatory effects on T cells, monocytes, and macrophages, producing altered cytokine activity locally. Topical corticosteroids inhibit collagen synthesis, potentially causing skin atrophy. They also inhibit IL-1, IL-2, IL-6, IFN-α, and tumor necrosis factor α.21 Topical corticosteroids are classified as class I (ultra-high potency) to class VII (low potency). In children, low-potency TCs generally are applied to the face, intertriginous areas, groin, and genitalia, and mid-potency corticosteroids are applied to the body, arms, and legs. An even higher-strength agent can be prescribed as a rescue medication in severe cases. After clearance with once- or twice-daily therapy, twice-weekly usage can benefit disease activity.22 Topical corticosteroids reduce inflammation as well as Staphylococcus aureus load through inhibition of cytokines that inhibit antimicrobial peptides. Topical corticosteroids have been endorsed as level IA evidence therapy by the AAD guidelines.14
Topical corticosteroids, particularly prolonged usage of mid- to high-potency products, have been associated with side effects such as skin atrophy, striae, telangiectases, hypopigmentation, rosacea, acneiform eruptions, focal hypertrichosis, perioral dermatitis, and acne23; potential systemic side effects include hypothalamic-pituitary-adrenal axis suppression, cataracts, glaucoma (with periocular application), Cushing syndrome, hyperglycemia, hypertension,23 and growth retardation.14 Long-term corticosteroid therapy is associated with tachyphylaxis and potential rebound of disease with discontinuation.24 Based on the potential risk of side effects with TCs, the least potent product for the shortest time needed is recommended, with special care for thin skin. Discontinuation when clearance occurs is advised. Allergy to TCs and/or vehicle ingredients such as propylene glycol should be suspected in severe unremitting cases.14 A recent registry review of children screened for contact dermatitis demonstrated that children with AD had higher sensitization to the steroid tixocortol pivalate.25
Topical Calcineurin Inhibitors
Topical calcineurin inhibitors include pimecrolimus cream 1%, which is approved for mild to moderate AD in adults and children 2 years and older, and tacrolimus ointment 0.03% and 0.1%, which are approved for moderate to severe AD in adults and children aged 2 to 15 years (0.03% formulation only). Topical calcineurin inhibitors can be used as second-line agents in AD in patients who have inadequate response to TCs or who may not be able to use TCs due to the disease site.10,13,14 Guidelines from the AAD also have endorsed TCIs as level IA evidence for steroid-sparing agents.
Concerns about the reporting of cancers and lymphomas prompted the US Food and Drug Administration to issue a black box warning on TCIs more than 10 years ago. Pimecrolimus, which has little absorption and no notable immunosuppressive effects, has been used without detrimental effect on vaccination and delayed-type hypersensitivities, but many decades of data are lacking.10,13,14,17,26-29 Topical calcineurin inhibitors can be used as steroid-sparing agents in lieu of corticosteroids in specific locations such as the face and eyelids and for long-term suppressive therapy twice weekly.30 Intermittent usage and cycling with corticosteroids is advisable,28 but usage intermittently beyond 1 year has not been evaluated.
Topical calcineurin inhibitors are recommended as effective for acute and chronic AD. Their use as maintenance therapy in adults and children, for AD recalcitrant to steroids, for AD in sensitive areas, for steroid-induced atrophy, and for long-term uninterrupted topical steroid usage carries a level IA evidence recommendation. Furthermore, the AAD guidelines have recommended TCIs as steroid-sparing agents with level IA evidence and off-label use of TCIs in children younger than 2 years with level IA evidence. Pretreatment with TCs to reduce stinging has level IIB evidence. Usage for flare prevention is level IA evidence. Routine blood monitoring of TCI-treated patients was not recommended; in fact, the AAD guidelines provided this recommendation as level IA evidence against routine laboratory monitoring of TCI-treated patients.14
Topical Antibiotics
Topical antibiotics are indicated for the therapy of impetigo and can be used in the setting of impetiginized AD in conjunction with TCs. Recent AAD guidelines suggested against routine usage of topical antistaphylococcal agents as level IA evidence.14 There is one study supporting usage of topical mupirocin in addition to TCs to heal children with eczema area and severity index scores more than 7 more rapidly in the first week of AD therapy, but in the same study, additive benefit was not demonstrated in AD beyond the first week.31 There also are data supporting usage of intranasal mupirocin adjunctively with bleach baths in patients with moderate to severe AD, which was rated as level IIB evidence in the AAD guidelines.14,32 There are limited data on the long-term utility of topical anti-infectives in AD. The risks of long-term usage could include resistance formation to agents such as mupirocin, contact dermatitis, and lack of efficacy.
