A conversation about nighttime itch with Gil Yosipovitch, M.D., dermatology professor at Miller School of Medicine at the University of Miami and the director of the Miami Itch Center

More than one-third (36%) of the total negative effect on quality of life from itch comes from sleep problems caused by chronic itch and 45% of the negative effect on daily functioning from itch is due to these sleep problems, according to research recently published in JAMA Dermatology.

A team of researchers, including Gil Yosipovitch, M.D., dermatology professor at Miller School of Medicine at the University of Miami and the director of the Miami Itch Center, drew data from deidentified surveys at the Miami Itch Center done as part of routine care.

Yosipovitch recently sat down with Managed Healthcare Executive to discuss the results and what they mean for the future of sleep-itch research.

This interview has been edited for length and clarity.

A team of researchers, including Gil Yosipovitch, M.D., dermatology professor at Miller School of Medicine at the University of Miami and the director of the Miami Itch Center, drew data from deidentified surveys at the Miami Itch Center done as part of routine care.

Yosipovitch recently sat down with Managed Healthcare Executive to discuss the results and what they mean for the future of sleep-itch research.

This interview has been edited for length and clarity.

MHE: Why is itchiness more commonly reported at night?

Yosipovitch: There are several explanations for that. One is that there are circadian rhythms of neuropeptides and cytokines, which are likely higher at nighttime. The skin barrier also is more permeable at nighttime, and the skin temperature goes up one degree Celsius, which activates nerves. A misconception is that patients are busier during the day and at night, they're more aware of the itch, but overall, it is more complex, and a lot of it is related to these physiological changes.

MHE: In this study, you write that chronic itch equates to chronic pain in terms of quality-of-life impairment. How so?

Yosipovitch: There have been studies that have shown that both itch and chronic pain are symptoms that are bothersome, and we know that the patients are significantly affected by that. The effect on quality of life and the fact that they don't sleep at night due to the itch are very similar to patients who have chronic pain. With chronic pain, there are also changes in circadian rhythms, and we know that the neuropeptides differ between day and night, so we now understand better that there is a significant impact on quality of life in patients with chronic itch very similar to chronic pain.

MHE: Participants were categorized into four itch subtypes. Can you describe the differences between them?

Yosipovitch: The first is what we call proprioceptive itch. These are the inflammatory skin diseases such as atopic eczema, chronic urticaria and psoriasis.

Then there's neuropathic itch, where there isn't really any rash, but there is nerve damage causing the itch, because the nerves are the ones that transmit itch. This could be from multiple causes, such as peripheral neuropathy or impingement of a nerve in the spinal cord causing itch.

The other type of itch, called CPU, or chronic pruritus of undetermined origin, we see a lot in elderly patients that don't have inflammation, but they have an itch. Sometimes there are secondary skin changes that you could see from the scratching, but there is no primary skin rash.

The last type, systemic itch, is related to underlying systemic diseases. The most common causes are end-stage renal failure and cholestatic liver disease.

MHE: The results showed that 36% of the quality of life outcome and 45% of functional outcome of itch may be associated with sleep disturbance. How significant are these findings?

Yosipovitch: Almost half of the patients were significantly impacted by their nighttime itch; more than half of the patients reported sleep disturbance. I think we need to address this issue more seriously, not just the patient’s itch but also the lack of sleep that these patients have.

MHE: What is the next step for this research?

Yosipovitch: There need to be multiple avenues for research. One is to better assess nighttime itch beyond using questionnaires. There are now wearable devices, and some use AI to analyze sleep quality and record scratching activity at nighttime. This is extremely important, especially for children who can't provide us with numerical rating scales of their itch level.