Eczema, also referred to as atopic dermatitis, is a relatively common skin condition affecting up to 20% of children and up to 3% of adults. This condition of exquisitely itchy and inflamed red patches of skin can have dire effects on normal sleep patterns in children, commonly leading to mood and behavioral problems. In fact, it is estimated that over 60% of children with eczema have major sleep problems. The symptoms of eczema can range from mild to severe, with itch as a prominent feature. Some children (and adults) are so itchy that they scratch repeatedly until their skin bleeds. This scratching makes the eczema worse, leading to a perpetual cycle called the “itch-scratch cycle.”
Interestingly, people with eczema report much worse itching at nighttime. One explanation is that the skin experiences changes in its various functions in a rhythmic pattern over a 24-hour period called the circadian rhythm.[4,5] The circadian rhythm is the result of a biological clock that governs important physiological functions throughout our entire body, from our heart rate, hormones, and sleep patterns all the way to our skin. Simply put, a biological clock in our brain called the suprachiasmatic nucleus sends signals to nerves and tissues throughout the body to operate based on approximate 24-hour patterns. In turn, our external environment (e.g., sunlight, climate, diet, and stress) can also affect the circadian rhythm.
Circadian rhythm patterns are observed in multiple skin functions, including skin cell turnover, the skin’s ability to retain water, sebum (skin oil) production, skin immune functions, and even DNA repair. At night, facial oil production is lowest, while skin blood flow and pro-inflammatory molecules reach a peak.[6,10] In contrast, transepidermal water loss is highest in the late afternoon and evening, leading to compromise of the skin barrier function. In people with eczema, these factors likely increase nighttime itch.
Melatonin is vitally important to regulate the circadian rhythm allowing for efficient sleep. A tiny gland in the brain called the pineal gland secretes melatonin; in addition, our skin cells, called keratinocytes, along with immune cells also produce a small amount of melatonin. Normally, melatonin secretion steadily increases and peaks around 3:00 AM, then gradually decreases, helping us to reach our deepest sleep during the night. In one study, researchers found that almost 78% of children with eczema had a significantly disturbed melatonin secretion pattern, with melatonin levels being abnormally low during eczema flares. On the other hand, normal to high levels of nighttime melatonin seem to be associated with less sleep disturbance and more mild eczema symptoms in children.
Melatonin supplementation in children with eczema may significantly improve sleep duration and quality. In a randomized controlled study, children with eczema received 3 mg of melatonin at bedtime for four weeks. The children who received melatonin had a significantly lower eczema severity score compared to the children that received a placebo supplement. These results were confirmed in a separate study that showed melatonin supplementation helped children with eczema to fall asleep much faster without being disturbed by the itch-scratch cycle.
Although melatonin supplementation is thought to be less harmful than traditional pharmaceutical sleep aids, there are still some side effects associated with its use. While the long-term risk of using melatonin supplements is largely unknown, the most common short-term side effects using the normal dose includes the following:
In the United States, melatonin supplementation falls under the category of dietary supplements, and therefore can be purchased over the counter without a prescription. Doses of some over-the-counter brands increase the level of melatonin in the body between 3-60 times more than the normal level needed to have an effect. High concentrations of the melatonin in the body may increase the potential for side effects such as impaired mental or physical performance. It is important to consult a doctor before taking melatonin supplements.
Sleep is an incredibly important mechanism by which the body repairs and restores itself. It is challenging for patients with eczema to get high quality sleep due to the constant disturbance caused by the itch-scratch cycle. Improved sleep can improve the symptoms of eczema. Although melatonin supplementation can be helpful in achieving fewer sleepless nights for eczema patients, other approaches to improving sleep quality include the following: