41% of people with long-term itchiness have fatigue, likely due to persistent sleep disruption, according to new research published in the British Journal of Dermatology. In comparison, only 22% of the control group had fatigue.

Chronic itch, known medically as pruritus, is defined as an itch that lasts longer than 6 weeks. It affects 1 in 6 adults, though the rate is much higher in the elderly. It can be a symptom of inflammatory skin conditions such as eczema, psoriasis, and hives, internal diseases such as liver disease, end-stage kidney disease, and blood malignancies, amongst other conditions. In about 8% of cases, there is no known cause of the itch.

Dr Gil Yosipovitch, University of Miami Miller School of Medicine, Director of the Miami Itch Centre, and lead author of the research said:

“We know that itch is amplified at night and that this contributes to sleeplessness, which over time can become fatigue. This research puts a number on the extent to which itch contributes to rates of fatigue. People with chronic itch are twice as likely to have fatigue compared to the general population. We know from previous research that this has a significant impact on people’s quality of life.

“Another finding of our research was that 68% of adults over 85 have fatigue. We know that changes to the immune system and skin physiology, which contribute to dry skin and immune dysregulation, mean older adults are much more likely to develop chronic itch. Future studies could explore whether itch is an important factor in these high rates of fatigue amongst the elderly.”

The researchers looked at data from 114,015 adult patients, contained in a data set from the US National Institutes of Health (NIH) All of Us Research Program. Within this database, people experiencing chronic itch were identified and the researchers reviewed how many of these had also developed fatigue.

Each person in the database experiencing persistent itch was then matched with four others, without itch, but who were otherwise similar in terms of their age, ethnicity, sex, income, education, anxiety, and depression. This group acted as a control group.

While it has long been known that there is a link between itch and fatigue, data quantifying the link is limited.

Persistent itch is easy to underestimate. Research shows that it is comparable to chronic pain. Sleep is just one of many areas of life that itch can devastate. Fatigue contributes to underperformance at work and school, can leave people without energy to do the things they love, affects our mental wellbeing and can damage relationships.”

Paula Geanau, British Association of Dermatologists

Itch is thought to contribute to sleep disruption due to nocturnal itch-scratch cycles. People with chronic itch regularly report that the itch is more intense at night. This can make it difficult to fall asleep or cause people to be woken by the need to scratch.