7.1 Local therapy
With respect to the skin barrier dysfunction as a pathognomonic factor in the pathogenesis of AE, emollient therapy marks an essential element in the disease management: Application of emollients in adequate amount (>250g/week) and frequency (at least once, better twice a day; additionally, after any skin cleansing) is necessary to enhance the integrity of epidermal barrier and consequently reduce the susceptibility for irritation and inflammation of the skin. Interestingly, a pilot study has recently shown greater efficacy of a novel trilipid cream (a 3:1:1 ratio of ceramides, cholesterol, and free fatty acids) than a regular paraffin-based emollient considering the reduction of transepidermal water loss [115].
Topical anti-inflammatory treatment is still the mainstay of mild-to-moderate forms of AE and especially acute exacerbations due to a reduction of pruritus and inflammation and restoration of skin barrier function. Both topical corticosteroids (TCS) and calcineurin inhibitors (TCI) have shown to be safe and effective for reducing acute flares and risk of relapse if applied in an appropriate intensity and dosage, especially in a proactive setting (e.g. twice weekly usage on predilection areas). Concomitant use of emollients in an appropriate amount has proved a steroid-sparing effect [116, 117]. Besides their anti-inflammatory properties, positive cutaneous microbiome effects have been shown for TCS and TCI.
Promising new topical agents that inhibit key regulators of pro-inflammatory signals are in clinical development (e.g. topical Janus Kinase Inhibitors) or have been recently approved (topical selective phosphodiesterase 4 inihibitor Crisaborole). Further studies will have to show their potential role in management of AE [112].
In many cases, adequate control of AE can be achieved by topical treatment options, if applicable even in combination with phototherapy (e.g. UVB, UVA-1). However, if local therapy remains insufficient, or in case of severe or persistent disease, systemic treatment is indicated.