Effects of Stress on Itch

Abstract

Psychological stress and ensuing modulation of the immune and nervous systems can have a significant impact on itch. Stress can exacerbate itch and vice versa, resulting in a vicious cycle that can greatly impair a patient's quality of life. This review summarizes the association between stress and itch, elucidates the mechanism by which these two phenomena influence one another, and explores treatment modalities that aim to reduce stress-induced itch. Methods: A complete search of the PubMed and Google Scholar databases was completed and literature pertinent to this review was compiled. Findings: Both acute and chronic stress can significantly affect itch in healthy individuals and in those diagnosed with itchy skin diseases as well as systemic diseases, thus resulting in a vicious cycle in which stress exacerbates itch and vice versa. The mechanisms by which stress induces or aggravates itch include both central and peripheral activation of the hypothalamic-pituitary-adrenal axis and sympathetic nervous system. Activation of these systems, in turn, affects the mast cells, keratinocytes, and nerves that secrete neuropeptides, such as substance P, nerve growth factor, acetylcholine, histamine, and itchy cytokines. A dysfunctional parasympathetic response is thought to be involved in the chronic stress/itch response. Brain structures associated with emotion, such as the limbic system and periaqueductal gray, which work on the descending facilitation of itch, play a significant role in stress-induced itch. Implications: As specific brain structures are associated with stress, drug treatments targeting these areas (ie, g-aminobutyric acideergic drugs, serotonin and norepinephrine reuptake inhibitors) may help to modulate itch. Stress can also be combatted using nonpharmacologic treatments such as cognitiveebehavioral therapies and stress-relieving holistic approaches (eg, yoga, acupuncture).

COVID-19, Mast Cells, Cytokine Storm, Psychological Stress, and Neuroinflammation

“…Psychological stress, anxiety, and fear can induce and increase itch sensation and exacerbate atopic dermatitis and urticarial disease severity in COVID-19 patients (Stefaniak and others 2020). Acute and chronic psychological stress can increase itch sensation through mast cell activation (Golpanian and others 2020). It is already known that mast cell–derived inflammatory mediators play an essential role in itch sensation in atopic dermatitis and urticaria, indicating mast cell involvement in COVID-19 pathogenesis.…”

The Skin Microbiota and Itch: Is There a Link?

“…Stress is a complex dynamic condition where homeostasis, or the stability of an organism is altered, promoting the adaptation of the host. Stress aggravates itch [115][116][117], which proves that the brain is engaged in the final common stage of itch processing [118,119].…”

New Frontiers in Psoriatic Disease Research, Part II: Comorbidities and Targeted Therapies

“…A recent study showed that patients with psoriasis who were exposed to videos of other individuals scratching exhibited changes in the white matter and functional connectivity of their brains (Najafi et al, 2020). Furthermore, regions of the brain that were shown to have higher connectivity in these patients included the bilateral cingulate gyri as well as the insula, regions known to be involved in the stress response (Golpanian et al, 2020).…”