Abstract
BACKGROUND: Neuropsychiatric disorders have been observed in mast cell activation syndrome (MCAS). MCAS is a common, yet rarely diagnosed, inflammatory, and immunologic disease characterized by mast cell dysregulation. METHODS: Questionnaires from 553 MCAS and 558 control subjects determined the prevalence and odds ratio of neurologic disorders (fatigue, cognitive dysfunction, fainting/near fainting, migraine-like headaches, muscle pain/tenderness/weakness, pain/numbness/tingling in extremities, restless legs syndrome, seizure-like activity, insomnia, sleep attacks, tinnitus, acoustic startle, Tourette's syndrome, resting tremor, and light/sun/pain/odors/scents/noise hypersensitivity) and psychiatric disorders (anxiety, agoraphobia, panic attacks, depression, bipolar depression, mania/hypomania, psychosis/schizophrenia, hallucinations, obsessive compulsive disorder, attention-deficit/hyperactivity disorder, anger management problems, post-traumatic stress disorder, suicidal thoughts, and eating disorders). RESULTS: Among 19 neurologic disorders, female MCAS patients reported higher rates in all but 1 disorder and male MCAS patients reported higher rates in all but 2 disorders. Among 14 psychiatric disorders, female MCAS patients reported higher rates in all and male MCAS patients reported higher rates in 8 disorders. Many of the disorders with increased prevalences were statistically greater compared to corresponding controls.In self-reported ratings for effects on health status (0 = no benefit, 10 = maximum benefit), mean (SD) response was 6.3 (2.5) for antihistamines, 5.6 (3.2) for low-dose naltrexone, and 5.6 (3.1) for benzodiazepines. CONCLUSION: MCAS subjects have significantly elevated odds ratios for many neuropsychiatric disorders and may see improvement of symptoms using MCAS-targeted therapies, suggesting that mast cell dysregulation affects the brain and peripheral nervous systems and contributes to neuropsychiatric symptoms. Certain mast cell mediators, specific genetic predisposition, and life experiences could determine which disorder is apt to develop or worsen.