Atopic Dermatitis: Understanding The Itch That Never Really Goes Away

Scientists may have found the answer to the mystery behind the itch caused by atopic dermatitis, which may never go away. Read on to know more.

By: Jahnavi Sarma | | Updated: April 5, 2021 6:56 pm

According to the researchers of this study, in atopic dermatitis, the itching can be horrific, and it can aggravate disease.

Eczema, or atopic dermatitis, is a skin disorder that is sometimes also called ‘the itch that rashes’. People with this condition have to suffer the itch, which begins even before the rash appears. In fact, in many cases, the itchiness of the skin condition never really goes away. This is a relatively common skin disorders and as many as approximately 9.6 million children and 16.5 million adults in the US alone suffer from atopic dermatitis. This disease can affect the quality of life for patients. Though doctors today know a lot more about this condition than, say, a hundred years back, many mysteries remain about the chronic itch. This makes this skin disease a challenge for doctors across the world. Now researchers from Brigham and Women’s Hospital and Harvard Medical School offers new clues about the underlying mechanisms of itch. Their study suggests a key molecular player known as cysteine leukotriene receptor 2 (CysLT2R) that may be a new target for intractable chronic itch. The Proceedings of the National Academy of Sciences published this study. Also Read - Frequent bleaching of face is not recommended: Know why

Chronic itch is pathological, not protective

According to the researchers of this study, in atopic dermatitis, the itching can be horrific, and it can aggravate disease. Researchers from the Brigham and Harvard Medical School collaborated for two reasons: One is an interest in science and a curiosity about the cysteine leukotriene pathway and the second reason is understanding the cause of itching and its connections to neurons. Researchers from the Center for Immunology & Inflammatory Diseases at Massachusetts General Hospital and at the University of Texas at Dallas were also involved in the study. Also Read - Dealing with an itchy scalp? 7 home remedies to get rid of it

According to the researchers, an itch is the result of activity of a subset of neurons. An acute itch may be a protective response to help you remove something that’s irritating the skin. But, according to the researchers, a chronic itch is not protective and can be pathological. The underlying mechanism that activates neurons and causes chronic itch is not well understood and new treatment is needed. Also Read - Psoriasis: Why early diagnosis and medication is important

Role of neurons in itching

For the purpose of this study, researchers looked for gene activity in dorsal root ganglia (DRG) neurons linked to itch in mice. They found a striking level of CysLT2R, which was uniquely and highly expressed in these specific neurons. They also found expression of this receptor in human DRG neurons. This led them to focus their analysis on the receptor’s role in itch signaling. Further studies revealed that activating this receptor induced itching in a mouse model of AD, but not in other mouse models. Mice that lacked CysLT2R showed decrease itching. Collectively, their findings pointed to the receptor’s key role in causing itch and potentially contributing to AD.

Link between immune system and nervous system

According to researchers, many studies have shown that there a complex interaction between the immune system and the nervous system where itching is concerned. Cysteine leukotrienes in neuro-immune cross-talks lead to itching. Leukotrienes are a class of lipid molecules that originate from white blood cells, such as mast cells, which are involved in allergy and inflammation. Today, the leukotriene inhibitor montelukast, which targets CysLT1R, is used to treat asthma. However, it does not provide relief from any kind of itching. No clinically approved inhibitors of CysLT2R currently exist. While researchers have seen evidence of the receptors in humans, until an inhibitor is developed and tried in humans, it will remain an open question as to whether the new target can lead to a therapy for atopic dermatitis patients.

(With inputs from Agencies)

Published : April 5, 2021 6:29 pm | Updated:April 5, 2021 6:56 pm

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