Mast Cells and Stress: The Mind-Body Connection

From initiating allergic immune responses to protecting against pathogenic threats, mast cells play an important role in the immune system. However, hyperactive mast cells and the sustained release of their associated inflammatory cytokines and mediators such as interleukin (IL)-6 and histamine impact multiple body systems and may cause impaired health. Identifying the triggers and contributors to mast cell dysregulation is an important approach when assessing chronic inflammation and a patient’s clinical presentation.

Chronic psychological stress is one lifestyle component that may lower the threshold for mast cell reactivity.^1,2 Hormones involved in the stress response such as corticotropin-releasing hormone (CRH) and cortisol are closely linked to mast cell activation and degranulation. Mast cells and associated stress hormones have been implicated in skin diseases such as psoriasis and chronic urticaria^3-5 and continue to be studied for their potential role in gastrointestinal disorders^6,7 and neuroinflammation.^8,9

A systems biology perspective may be most effective to address the complexity of multisystem inflammation that involves dysregulated mast cells. Specific to chronic stress exposure, lifestyle approaches, including mind-body therapies, may help to attenuate the stress response, downregulate the inflammatory cascade, and calm mast cell reactivity. What mindfulness-based practices may align with your patient’s treatment strategy and health goals?

Skin, Stress, & Mast Cell Activation

Compiled research suggests that the skin responds to psychological stress through the complex interactions of skin-based immune cells, hormones, and neurotransmitters.^3,4 Under stress, keratinocytes and mast cells have been found to increase secretion of the inflammatory cytokine IL-6 and stress-related mediators such as cortisol and corticotropin-releasing hormone (CRH).³ Specific to urticaria pathology, skin mast cells activated by CRH contribute to vasodilation and increased vascular permeability,⁴ and stress may amplify these conditions. A 2020 systematic review of human in vivo and ex vivo studies reported that while further investigation into underlying causal factors is warranted, a significant association exists between chronic urticaria, mast cell mediators (i.e., histamine), neuroimmune inflammation, and stress exposure.⁴

Psoriasis is a chronic autoimmune skin disease. While stress has previously been highlighted as a risk factor for autoimmune conditions,¹⁰ research investigations continue to detail the mechanisms and the role of mast cells in the psychological stress-psoriasis relationship.¹¹ Most recently, studies indicate that skin mast cells near psoriatic plaques express receptors for the stress hormone CRH, which may increase CRH-induced mast cell secretion of inflammatory cytokines such as IL-6.⁵ The secreted IL-6 may then contribute to psoriatic lesion pathogenesis and further hypothalamic-pituitary-adrenal (HPA) axis dysregulation.⁵

Stress & Mast Cells: A Gut-Brain Perspective

Mast cell mediators have been implicated in gastrointestinal disorders and neurological conditions such as irritable bowel syndrome (IBS)¹² and migraine.¹³ While exact pathogenic pathways and mechanisms are not yet clarified, human studies and animal models continue to illustrate the impact of psychological stress on mast cells operating within the gut-brain axis.^6,8,9,14 A 2022 study that used a mouse model of eosinophilic enteritis found that psychological stress exposure worsened small intestine inflammation, increased intestinal permeability, and significantly increased both the intestinal mRNA expression of CRH and the number of mast cells compared to controls.⁷ A 2020 clinical study (n=21 patients with irritable bowel syndrome with diarrhea [IBS-D] and 17 healthy controls) investigated the role of CRH, also called corticotropin-releasing factor, on IBS mucosal function.⁶ Intestinal responses were evaluated in subjects after receiving 5-mL saline solution (placebo) and CRH (100 μg), and researchers reported the following results:⁶

• Compared to healthy subjects, base measurements of mast cell–associated and affected proteins (tryptase and albumin) were higher in patients with IBS-D.
• Albumin output increased for patients with IBS-D after CRH exposure.
• Tryptase release, a marker for mast cell activation, increased significantly for both groups after CRH exposure.
• Abdominal pain worsened only in patients with IBS-D after CRH exposure.

Research also continues to investigate suggested neuroimmune connections between stress-mediated mast cell activation and the pathogenesis of neurological diseases. CRH activation of mast cells, potential disruption of the blood-brain barrier, intestinal permeability, and neuroinflammation are some of the components recently evaluated in this complex, multisystem relationship.^8,9

Lifestyle Approaches: The Mind-Body Connection

Stress is a common trigger for a wide range of mast cell activation symptoms.² An older survey conducted by the Mastocytosis Society in 2014 found that among 366 members of the US-based advocacy, research, and education organization for patients with mast cell–related disorders, 81% identified stress as a trigger for their mast cell–related symptoms.¹⁵ Research studies continue to clarify the critical mechanisms and pathways involved in stress-mast cell interactions, and they continue to investigate the impact of mind-body and stress transformation therapies as adjunctive treatments for mast cell dysregulation and symptomology.^1,16,17

A 2022 systematic review of 40 studies (n=3,112 patients) evaluated the efficacy of psychological therapies and mind-body practices in the management of dermatologic diseases, primarily psoriasis and atopic dermatitis.¹⁸ Investigators found that the most promising practices were cognitive behavioral therapy, mindfulness-based interventions, and habit reversal therapy.¹⁸ A 2022 systematic review specifically evaluated meditation as an adjunctive treatment for psoriasis symptoms, severity, and patient quality of life.¹⁹ Of the six randomized controlled trials included in the review, five showed reduced disease severity after eight to twelve weeks of guided meditation and one measured positive mental health benefits in psoriasis patients.¹⁹ Beyond the skin, mind-body practices such as mindfulness-based cognitive therapy have also shown benefit for reducing symptoms and improving quality of life in patients with IBS.²⁰

In addition to disease-specific benefits, studies suggest that mindfulness and mind-body practices help to improve overall levels of stress-related hormones^21,22 and inflammatory cytokines.^23,24 As an example, a 2022 randomized controlled trial (n=281) evaluated the benefits of integrative-body-mind-spirit (IBMS) and Qigong interventions for patients with both depressive symptoms and reported sleep disturbance.²⁵ After eight weekly interventions, compared with controls, IBMS and Qigong were effective for relieving depression symptoms and reducing both sleep disturbances and levels of the inflammatory cytokines IL-6 and IL-1-beta.²⁵

Mind-body therapies may help reduce stress, regulate mast cell hyperactivity, and improve a range of health-related symptoms. Identifying sources of chronic stress and incorporating stress transformation practices that best suit a patient’s lifestyle and preference is part of the functional medicine approach to improved health and wellness. The IFM Toolkit provides easy and accessible resources to personalize lifestyle-based therapies and includes Strategies for Transforming Stress. This toolkit item suggests a range of stress-relief practices, from community support, spiritual practice, and laughter to journaling, practicing gratitude, and meditation. Learn more about lifestyle-based interventions and the functional medicine approach to immune health and resilience at IFM’s upcoming Immune Advanced Practice Module (APM).