Regular, high-quality sleep is necessary for proper physical and mental health. Doctors have long recognized that patients with chronic illness tend to develop secondary disturbances of sleep, that can be anywhere from minimally to significantly life impacting. In atopic dermatitis, sleep disruption correlates with disease severity, as well as behavioral manifestations. However, only in the past few years have studies been published which show how tightly entwined high-quality sleep is to skin health.
Circadian Rhythm and Sleep
This topic is extremely broad and worthy of several full-length books on its own. For this discussion, we will only talk about its relationship with pediatric atopic dermatitis. Circadian rhythm refers to the body’s daily clock. This clock is centered in the brain and runs a complex arrangement of rising and falling hormones, energy levels, and other metabolic processes. This clock is designed to fit into a 24-hour period of time. This is driven by the cycles of light and dark and can be easily interrupted by disturbances in the environment, light quality, and medications. The itching from atopic dermatitis is worse at night, due to multiple reasons.
Skin Barrier Function and Sleep
Skin is designed to keep water/hydration inside the body. The skin normally allows only for minimal water loss, usually through evaporation to cool the body, however, the breakdown of the skin barrier from atopic dermatitis is associated with increased water loss through the skin, a metric known as Trans Epidermal Water Loss (TEWL). Due to circadian rhythm's impact on skin blood flow, the skin normally has decreased TEWL at night, this is not true for skin affected by atopic dermatitis. In the areas affected by eczema, TEWL increases at night. The increased loss of hydration directly increases the itching associated with the condition.
Immune System Function and Sleep
Another exciting area of research that has had a significant increase in interest is not only the impact of the central circadian clock on the immune system but that the immune system has a clock of its own. We understand now that certain cells of the body, such as T cells, and mast cells, have their own 24-hour clock which is separate from the body’s central clock. Mast cells, which are the skin cells that release histamine that causes itch, are much more active at night than the daytime. This nighttime activity is thought to increase the amount of itching, which leads to disruption of quality sleep due to distraction, disruption, and scratching.
Hormones (Cortisol/Melatonin) and Sleep
Part of the 24-hour clock’s regulatory process involves the production of many different hormones which all directly influence body processes. There are dozens of hormones that are altered by the sleep/wake cycle as well as light patterns. Two very important clock generated hormones for atopic dermatitis include cortisol and melatonin. Cortisol has anti-itch properties, and peaks in the morning and is lowest at night. Our body's regulation of cortisol can be altered by the use of oral steroids, or in some cases high-dose/high surface area use of topical steroids.
This pro-sleep, anti-inflammatory hormone, generally increases within the first part of the sleep cycle, and continues to increase for the first few hours of sleep, then trails off leading to awakening. Very recently, a study was performed that the production of melatonin is significantly disrupted in patients with severe atopic dermatitis, and correlates with worse quality of sleep in those patients.
What Can be Done to Improve Sleep
Dust Mite Control
Control of itch at night is challenging, and generally takes a significant amount of efforts and multiple facets of garments as well as skin care. Dust mite control is highly effective with mattress encasements as well as weekly washing of sheets and bedding with high-temperature settings. Dust mites are a major sensitizer in pediatric atopic dermatitis, and allergic sensitivity to dust mites is known to be found in more severe cases of atopic dermatitis.
Skin Barrier Function
Wet wrap therapy, including the use of specialized garments, can significantly improve barrier function at night as well as increase the effectiveness of medications delivered to the skin. This can decrease the TEWL, improve sleep quality, and accelerate healing.
Blue light, which is produced by computer and phone screens, will directly inhibit the production of melatonin. This significantly decreases sleep quality and makes it harder to fall asleep. Closing down all electronic devices, and television shows at least 60-90 minutes prior to sleep is recommended to reduce exposures to blue light sources. There are several downloadable applications that are reported to reduce the levels of blue light produced by device screens, however, there have been no studies that show that these are effective in improving the quality of sleep. Several of my patients reported success with the use of these applications, but they have not entered normal clinical prescribing.
Darkness, directly causes the production release of melatonin. An important aspect of sleep hygiene is an adequately dark room, with no light either from the street, computer devices are televisions. This is an often overlooked aspect of sleep hygiene, which is extremely important for the normal production of melatonin.
The use of melatonin was studied in children with atopic dermatitis under the age of 18. The use of 3 mg. of melatonin prior to sleep was associated with improvement in all scores of atopic dermatitis, including itch, and TEWL.
Please remember information on our blog is not designed or meant to replace a physician’s advice. Always consult your doctor about your medical conditions. AD RescueWear does not provide medical advice, diagnosis or treatment.