Imagine that you come home exhausted after finishing that project you have been working on for days or maybe so worn out after a day shift that had to finish early. Now you want to lie in your comfy bed only to find yourself unable to fall asleep because of the unexplained itching all over the body at night.

This itching might have started recently or continued for quite some time without any relief, even after using powders, lotions, or creams. Moreover, you might also have sought advice from your friends, family, coach, internet, or a pharmacist before consulting a doctor for something so ‘seemingly’ trivial.

Itching has bothered everyone almost once in a while, some more frequently and longer than others

Maybe now is the time to know more about the cause of the unexplained itching all over the body at night!

Itching or pruritus is a term used to describe the sensation that causes an urge to scratch.

In addition, itching that is not relieved even after scratching and is associated with a sensation that something inside the body is itching is usually associated with psychological disorders or drug abuse. This may cause unexplained itching all over the body at night.

Nocturnal pruritus describes the itching that occurs during the nighttime.

We go through different stages of sleep throughout the night. Most people experience itching during the 1st, 2nd, and REM stages of sleep, and it is less common in the deepest stage (3^rd).

In addition, you are more likely to wake up because of itching than before it starts.

What causes unexplained itching all over the body at night?

The answer is incompletely understood.

Some skin functions may be altered during sleep, including thermoregulation, maintenance of fluid balance, and barrier function. Abnormalities in each of these and the physiological changes during the circadian rhythm could be responsible for causing nocturnal pruritus.

1. Circadian rhythm

These rhythms repeat every 24 hours and control sleepiness, wakefulness, hunger, digestion, etc. They may also play a role in nocturnal pruritus. The hypothalamus-pituitary-adrenal (HPA) axis releases corticosteroids continuously throughout the day. Their levels are lowest during the late hours, leading to increased inflammation and itching at night.

2. Thermoregulation

The hypothalamus has a set point for controlling our body temperature. During sleep, this set-point is lowered to cause increased blood flow towards the skin and away from the core, which cools down our body.

As a result of a decrease in core body temperature achieved at the cost of increased blood flow through the skin, we may experience more itching during the night.

3. Alteration of the skin barrier and fluid loss

The skin barrier prevents external substances of the environment from entering the skin. It is impaired during the night, so our skin comes in contact with more irritants and allergens.

The altered skin barrier and increased fluid loss through the skin might be responsible for increased itch intensity in patients with atopic eczema.

4. Other abnormalities

Other chemicals or hormones may also be causing circadian rhythm abnormalities responsible for nocturnal itching:

1. Abnormal levels of prostaglandins, cytokines, nerve growth factors, and opioids.
2. Hormonal changes – Melatonin is a hormone that regulates circadian rhythm and sleep cycle. If secreted in higher amounts, it may improve sleep quality.
   • For example, in children with atopic eczema melatonin may be decreased in amount contributing to their poor sleep. Moreover, melatonin supplementation may help them sleep.

The psychological effect of chronic itching all over the body

Itching lasting weeks to months may be associated with stress and depression, which affects the productivity of an individual. In children, eczema may even lead to behavioral and neurological deficits.

Of all the possible explanations behind itching at night, the most plausible is “anxiety.” You might be itching more at night simply because you are ruminating and more anxious than during the day.

Itching causes skin inflammation, which further increases the itching and scratching, known as the itch-scratch cycle. Therefore, the patients are unaware of the extent of their itching, which significantly impacts the individuals’ sleep and quality of life.

What conditions may cause unexplained itching all over the body at night?

1. Skin conditions

Itching related to common inflammatory skin conditions could be worse at night like:

• Psoriasis
• Chronic urticaria or hives
• Lichen simplex chronicus or neurodermatitis

2. Allergies

Allergies could cause the skin to itch at night, and the allergen may not always be identified. Atopic eczema is commonly thought to be caused by allergens inside our own body, therefore also called endogenous eczema.

People with atopic eczema suffer from a contagious itch with a tendency to itch after seeing other people itching due to activation of the central connections of the itch pathway.

3. Infestations and infections

Bed bugs, lice, and mites cause itching, especially when they are more active at night. Scabies is one of the most common reasons for itching occurring at night.

Fungal, bacterial, and viral infections, including HIV, could also be responsible for nighttime itching.

4. Psychological disorders

Stress, anxiety, depression, and schizophrenia can contribute to unexplained itching all over the body at night. Parasitic delusions feel like insects or objects crawling under the skin when there are none. They may be associated with substance abuse (especially cocaine), and psychological or medical disorders.

5. Disorders of systems other than the skin

• Liver disease
• Kidney disease
• Blood disorders like leukemias, lymphomas, anemia
• Neurological disorders like neuropathies, shingles
• Diabetes
• Hyperthyroidism or hypothyroidism

Liver and kidney diseases are among the most common causes of intense itching. Liver disorders cause itching, especially on the hands and feet.

6. Medications

Drugs used to treat pain, hypertension, heart diseases, cancer, infections, psychological disorders, etc. can be responsible for itching.

Even after identifying all the major causes, there might still be unexplained reasons for itching over the body during the nighttime, which might require undergoing extensive tests, lifestyle modifications, and taking medications for a long time after consulting your doctor.

Now that you know some causes that explain why you might be itching all this time, what can you do about it?

Some preventive measures include avoiding known allergens, maintaining a consistent sleep routine, keeping nails trimmed to prevent skin damage from scratching, and bathing in cool or lukewarm water before bedtime.

If you found this article helpful, don’t keep it to yourself! Share your thoughts in the comments below and hit that like button to let us know.

References

1. Lavery MJ, Stull C, Kinney MO, Yosipovitch G. Nocturnal pruritus: The battle for a peaceful night’s sleep. Int J Mol Sci 2016; 17: 425.
2. Thorburn PT, Riha RL. Skin disorders and sleep in adults: Where is the evidence? Sleep Med Rev 2010; 14: 351–8.
3. Zhao ZD, Yang WZ, Gao C, Fu X, Zhang W, Zhou Q, et al. A hypothalamic circuit that controls body temperature. Proc Natl Acad Sci USA 2017; 114: 2042–7.
4. Lee CH, Chuang HY, Shih CC, Jong SB, Chang CH, Yu HS. Transepidermal water loss, serum IgE and β-endorphin as important and independent biological markers for development of itch intensity in atopic dermatitis. Br J Dermatol 2006; 154: 1100–7.
5. Chang Y Sen, Chou YT, Lee JH, Lee PL, Dai YS, Sun C, et al. Atopic dermatitis, melatonin, and sleep disturbance. Pediatrics 2014; 134: e397–405.