Multiple Chemical Sensitivity Syndrome (MCS)

Multiple chemical sensitivity (MCS) , renamed idiopathic environmental intolerance by its skeptics, is an acquired, chronic, often disabling polysymptomatic condition. The core symptom of MCS consists of flares of illness from exposures to low levels of multiple chemicals from the environment. MCS involves a two-step process of initiation, followed by elicitation. Survey data indicate that although patients will report similarly high current reactivity to multiple environmental chemicals and foods at the elicitation phase (the precise eliciting agents and symptom manifestations vary among individuals), the initiation process by history ranges from a single identifiable high-dose chemical exposure to a series of lower-dose exposures to no identifiable chemicals at all. 

Heterogeneous Mechanisms

The pathophysiology of MCS is not well understood. 

  • Leading possibilities: 

(1) time-dependent or neural sensitization of central dopaminergic pathways 

(2) neurogenic inflammation involving trigeminal nerves leading to sinusitis, or neurogenic vasodilation leading to migraine headache

 (3) elevated nitric oxide/peroxynitrite contributing to sensitizing and inflammatory events

(4) chronic systemic inflammation triggered by exogenous agents

  • Most patients have reactions to common foods such as corn, egg, wheat, yeast, milk, beef, tomato, and potato, as well as food additives (colorings, preservatives). Anaphylactoid reactions are less common and IgM and IgG antibodies to certain foods in some patients (e.g., those with irritable bowel syndrome) have been demonstrated
  • Clinically, MCS overlaps other controversial syndromes such as fibromyalgia and chronic fatigue syndrome. Case definitions vary, but they typically include symptoms of central nervous system dysfunction such as difficulty concentrating, fatigue, migraine headache, irritability, and other mood instability. Arthralgias, irritable bowel syndrome, and rhinitis, as well as sinusitis, ovarian and breast cysts, and menstrual disorders are also common in MCS. Family histories of patients with MCS are notable for an increased prevalence of heart disease, hypertension, diabetes mellitus, sinusitis, rhinitis, and substance abuse, especially alcoholism (e.g., 20% versus 6%).
  • Demographically, MCS is more common in women than men. The typical age at the time of diagnosis is in the 30s to 40s and psychiatric comorbidities are common but not universal among patients with MCS. 
  • Clinically, patients with MCS report poor tolerance of drugs and alcohol, but addictive-like responses to craved foods, especially those with wheat, yeast, milk, corn, and sugar constituents. The leading mechanism for MCS from addiction research is time-dependent or neural sensitization. Sensitization of the dopaminergic mesolimbic pathway may mediate the development of cravings for drugs of abuse, including alcohol, and sucrose (which cross-sensitizes with stimulant drugs).

Integrative Therapy

Self-care lifestyle, mind-body therapy, and constitutional treatments are more helpful and less harmful. Pharmaceutical drugs, especially antidepressants and anxiolytics, reportedly cause more harm than benefit for a large proportion of individuals.

Prevention Prescription

  • Choose home and work settings away from highly polluted locations, such as away from major highways.
  • Avoid routine use of toxic pesticides and herbicides in and around the home and work environment. Seek safer, less toxic alternatives to deal with pests.
  • Ventilate indoor areas undergoing remodeling and do not attempt to spend extended periods of time in the areas until remodeling has been completed and the area has been well ventilated for days to weeks (or even months).
  • Avoid any indoor environment that becomes contaminated with molds; find alternate housing or workspace immediately.
  • Eat organic and chemically less contaminated foods whenever possible, in a diversified diet plan (in terms of botanical food families).
  • Drink environmentally uncontaminated, clean water (tested for consistent purity).
  • After acute unavoidable exposure to a toxic chemical that could initiate chemical sensitization, take detoxification steps (discard clothing, wash skin thoroughly, spend extended periods in clean open air; use any facilitating agents as recommended by clinical toxicologist 
  • Furnish home and office with glass, metal, less treated woods, and natural fabrics such as cotton rather than synthetics.
  • Wear untreated or chemically less treated clothing, especially from natural fabrics such as cotton.
  • Avoid or minimize regular use of scented products in home and for personal hygiene.

Therapeutic Review

  • Rotation Diet of less frequently eaten foods
  • Eliminate craved foods for at least 3 months; establish a rotation diet for testing and treatment of less frequently eaten foods. 
  • Exercise:Encourage low-impact aerobic exercise, especially for people with overlapping conditions of chronic fatigue syndrome and fibromyalgia. 
  • Spiritual and Mind-Body Interventions (e.g., prayer, meditation, support group, yoga, hypnosis, guided imagery, mindfulness meditation, supportive psychotherapy) 
  • Constitutional Energy-Based Therapy:Acupuncture, classical homeopathy, Ayurveda, or a specific energy therapy such as healing touch or qi gong may help. 
  • Manual Manipulation Therapy:Massage, osteopathy, and chiropractic may be helpful adjuncts, especially in patients with musculoskeletal issue.
  • Supplements:Patients report good help-to-harm ratios from Lactobacillus acidophilus, magnesium, vitamins C and E (presumably mixed tocopherols, but no data exist), and milk thistle seed. Consider adding other antioxidant supplements promoting glutathione production such as vitamin C 250 mg and N-acetylcysteine 200 mg once or twice a day. Use a geriatric dosing program of one fourth to one half of the usual adult dose, to start. 
  • Detoxification:Oral chelation therapy for heavy metal body burden and Sauna detoxification 
  • Pharmaceuticals:Minimize the use of drugs. Patients rate most psychopharmacologic interventions (antidepressants, anxiolytics) as more harmful than helpful, but some find nystatin or fluconazole (Diflucan) for presumptive systemic Candida/yeast infection more helpful than harmful. Use a geriatric dosing program of one fourth to one half of the usual adult dose, to start.

Case Study: DJ, a 54 years old female arrived to my office with complaints about sensitivities to perfume, shampoo and skin lotion. The symptoms included migraine headache , dizziness, nausea, low concentration, sensitivity to light, burning eyes, fatigue, sore throat as well as sores on her tongue. Her symptoms have worsened over time. She was diagnosed with multiple chemical sensitivity syndrome and was taking the following medicine as the time of presentation: 

1-Bupropion XL 300MG qd 

2- Clonazepam0.5 mg 2 tab bid

 3- B12 1000mcg qd

4- D3  1000 mg qd

She has a history of acid reflux, and had received treatment for helicobacter infection. Her family history includes CVD, alcoholism and IBS/ IBD. Her house presents some potential allergic triggers that include a damaged carpet, gas leak and possibly mold. She also suffers from  insomnia, low energy, a stressful job, grief  and a lonely life.

Treatment approach: She was very frustrated with chronic and persistent symptoms in addition to her ongoing stress generated by her family, her work place and so on. Treatment focused on eliminating environmental triggers, implementing an elimination diet, improving her digestion system and modulating immune response by prescription probiotics. I also included NAC  500 mg bid(to support respiratory tract & detoxification), B6 100 mg every night (support mood and sleep), nervine herbs(Herbal Calm bidr to support sleep and reduce stress), Quercetin 500mg+bromelain 200mg BID (to support body for allergy reaction, anti-inflammatory). 

Follow up: she returned after one month. She felt better and did not experience any additional attacks over the past month. She  continues to complain of insomnia, overthinking and stress, and was advised to reduce her stress with exercising (mild to moderate intensity) as well as maintaining sleep hygiene.