Pruritus or itchy skin is often times exacerbated at night resulting in sleep disturbances and deterioration in the quality of life.
In patients with inflammatory skin conditions such as psoriasis and atopic dermatitis, up to 65% report increased night-time itching, also known as Nocturnal Pruritis.
It is also common in scabies and has been reported in patients with systemic diseases such as liver disease and chronic kidney failure.
The disruption of sleep patterns due to nocturnal pruritus can cause some children with atopic dermatitis to lose an average of 46 minutes of sleeping time.
Adult patients with atopic dermatitis have been reported to sleep less and awake twice as often as other adults, which results in lower overall sleep quality.
Sleep deprivation can consequently contribute to irritability, daytime somnolence, impaired functioning and psychological problems.
Reduced sexual desire and sexual function are also reported amongst many patients suffering from Nocturnal Pruritis.
Pruritus also leads to increased skin inflammation, which causes further itching and scratching, known as the itch-scratch cycle.
Why does the itch become worse at night?
The underlying mechanisms responsible for night-time itching are not well understood. One possible explanation may be related to trans-epidermal water loss (TEWL), a measure of skin barrier integrity.
TEWL is significantly increased during the night and is minimal during the day.
The higher TEWL in the evening suggests that the epidermal barrier function is not optimal at this time, possibly facilitating the entry of irritants and itch-causing agents.
The nighttime increase in skin temperature may provide another plausible explanation for the exacerbation of Pruritus. Our core temperature is maximal in the early evening and minimal in the early morning.
Itching has also been reported to be aggravated by ambient heat on nerve endings.
The circadian rhythm, responsible for the fluctuating differences in many chemicals in the human body according to the day-night cycle, may also play a role.
For example, corticosteroids which are an anti-inflammatory hormone is low in the evening and at night.
This leads to a decreased anti-inflammatory response and may facilitate the worsening of Nocturnal Pruritus.
How to manage Nocturnal Pruritis
Nocturnal Pruritis and sleep deprivation have many deleterious health effects. Pruritis among patients undergoing hemodialysis has been reported to cause a 17% increase in risk of death, probably due to decreased quality of sleep.
Sleep-deprived individuals have been determined to have higher levels of Grehlin, which drives appetite, and may lead to weight gain and obesity.
This may, in turn, lead to further complications, such as diabetes mellitus, hypertension, cerebrovascular events and ischemic heart disease.
There are many over the counter and prescription drugs for Nocturnal Pruritis. Topical corticosteroids and sedating antihistamines are some of the medications used.
Antidepressants such as Mirtazapine are also given due to its antihistamine properties. Other medications include benzodiazepines, k-opioid agonists and gabaergics.
As the chemical fluctuation induced by the circadian rhythm is influenced by light and melatonin, bright light therapy and melatonin are also suggested as treatment options for Nocturnal Pruritus.
Bright light therapy directed towards the eyes has been successfully used to treat the severe itch of Cholestasis while controlled-release melatonin has been shown to improve sleep quality in the elderly.
Besides medication, here are some home treatments and preventive measures:
• Ensure adequate moisturisation. Moisturisers and emollients will not only hydrate the skin but help produce an occlusive film that limits water evaporation.
Moisturisers with a low pH may be especially useful in optimising the skin’s barrier function through their maintenance of the normal acidic pH of the skin’s surface.
• Take a bath or shower. Bathe in cool or lukewarm water before bed, using fragrance-free soaps, baking soda, or colloidal oatmeal. Rinse throughout and apply moisturiser.
• Use a humidifier in the bedroom to moisten the air.
• Apply a cool and wet compress, such as a cold, damp cloth, to the skin before bed.
• Use a fan to create airflow and background noise as a source of mental distraction.
• Avoid scratching as it can further irritate the skin. Trim your fingernails or wear gloves or mittens at bedtime.
• Wear comfortable sleepwear that is loose fitting to allow the skin to breathe.
• Avoid trigger factors. Check the bedroom for signs of bed bugs or other insect infestations. Avoid having a pet in your bedroom.
• Relax. Stress can further exacerbate Pruritis. Use meditation or relaxation techniques such as visualisation before bed.
Caffeine-free tea, such as chamomile or peppermint, may soothe you before bedtime. 2 to 3 drops of relaxing essential oil such as lavender on the pillow, may help you get a good night sleep.
This article first appeared in hellodoktor.com and was reviewed by Dr Duyen Le. The Hello Health Group does not provide medical advice, diagnosis or treatment.