Complex Chronic Disease · Mast Cell Activation Syndrome
Real Solutions for Mast Cell Activation Syndrome
Burning skin, unexplained flushing, food and chemical reactions, crushing fatigue — and years of being told it’s “just stress”? There’s a real, treatable cause.
“So many patients come into my office after being told there are no solutions — or worse, that it’s all in their head.”
I take a root-cause, evidence-based approach to diagnosing and treating MCAS — identifying triggers like mold and environmental exposure, calming the immune system, and rebuilding your tolerance instead of just chasing symptoms.
Joseph Mather MD, MPH
Board-Certified Family Medicine
- ✓ Over a decade of experience treating MCAS and complex chronic illness with a functional approach
- ✓ World class medicine — works with patients across the globe
- ✓ Specializes in uncovering mold and environmental triggers other doctors miss
- ✓ Educator and mentor offering CME education for physicians
Functional Medicine Expert — Treats the Cause of Disease
Board-Certified American Board of Family Medicine
Tulane School of Medicine & Tulane University School of Public Health
Watch: Kat's MCAS Patient Story
For years, Kat lived with skin that burned so badly a shower felt unbearable, along with debilitating fatigue and joint pain that made caring for her infant daughter a daily struggle. It took years to get a diagnosis: Mast Cell Activation Syndrome, triggered by mold exposure at her workplace. Watch her full story of healing — and why I believe there are real, natural solutions even for patients who’ve been told there aren’t.
Does this sound like you?
✓
Your skin flushes, burns, or itches for no clear reason — even clothing or a shower can feel unbearable
✓
You react to a growing list of foods, medications, or chemical smells
✓
You have crushing fatigue and joint or muscle pain that doesn’t add up on standard labs
✓
You get GI symptoms — bloating, cramping, diarrhea — alongside skin or breathing symptoms
✓
Your symptoms flare after mold, chemical, or environmental exposure
✓
You’ve been told your labs are “normal” and that stress or anxiety is the cause
What Is Mast Cell Activation Syndrome?
Mast cells are immune cells stationed throughout your skin, gut, and airways, ready to release histamine and other chemical messengers to protect you from threats. In MCAS, these cells become chronically over-reactive — firing off in response to foods, medications, temperature changes, stress, or environmental exposures that shouldn’t trigger a reaction at all.
The result is a pattern of symptoms across multiple body systems at once: skin flushing or hives, GI upset, headaches, fatigue, and more — symptoms that often look “normal” on standard bloodwork, which is exactly why so many patients spend years searching for an answer before finding one. In many patients, a specific trigger — commonly mold or another environmental exposure — sets this cascade in motion in the first place, and identifying it is a key part of getting well.
How my medical office is different
Three ways I’ve built this practice differently than a typical doctor’s office — or a typical functional medicine office.
01
Time to listen, think, and research
I run an independent private practice, free of hospital and insurance demands, so that I have the time to listen, think, and research your case properly.
I take a lot of pride in the fact that I am one of the few doctors who has been able to build my knowledge and skills day after day to make sure you get the best care possible.
My goal is for you to leave my office thinking:
“That was the best doctor’s visit I ever had.”
02
Treating the cause — without overdoing it
I treat the cause of your symptoms with natural and conventional medicine. But unlike other functional medicine offices, I don’t require thousands of dollars of labs or ask you to take hundreds of pills to get better. My goal is to get you well as quickly as possible — with the fewest supplements, the broadest diet that keeps you healthy, and a treatment plan that’s practical and down to earth.
03
Functional medicine you can afford
Paying out of pocket for medical care can be daunting. Because I want to help as many patients as possible, I’ve done all that I can to make care affordable:
- ✓I charge less than other experts in the field, despite getting better outcomes for my patients
- ✓I never profit from any testing I recommend
- ✓30% off supplements from Moss Nutrition
- ✓Discounted wholesale cash lab pricing through Clinical Pathology Labs for New Orleans patients
- ✓No subscriptions or memberships — ever
My approach to MCAS
A step-by-step, root-cause plan for calming mast cell reactivity and identifying what’s driving it — not just suppressing symptoms indefinitely.
1
Confirm the diagnosis carefully
MCAS is a clinical diagnosis built from your symptom pattern, history, and, when appropriate, mediator testing. I take the time to distinguish it from mimicking conditions rather than applying the label reflexively.
2
Identify your triggers
Mold and other water-damage-related exposures are among the most common drivers I see. We work to identify environmental, dietary, and chemical triggers — and address exposure at its source, not just the reaction to it.
3
Calm the immune response
A targeted low-histamine diet trial, mast cell-stabilizing supplements, and gut-repair strategies work together to reduce the frequency and severity of flares.
4
Support detoxification where needed
When mold or another environmental toxin is a driver, supporting your body’s natural detox pathways is part of the plan — always after exposure is addressed first.
5
Rebuild tolerance and reduce your reactivity over time
The goal isn’t a lifetime of restriction. As the underlying drivers are addressed, most patients are able to broaden their diet and tolerance again — and get their life back.
The science behind a natural approach to MCAS
A few of the published studies behind this approach.
Recommended Reading
Toxic: Heal Your Bodyby Neil Nathan, MD — foreword by Dr. Joe Mather
I’m proud to have authored the foreword to Dr. Nathan’s updated book, Toxic. This is the book I recommend to patients who’ve been told there’s nothing more anyone can do for them, or who feel completely lost. It covers the same ground Dr. Nathan and I walk through in our roundtable conversation, in far more depth: mold, Lyme and its co-infections, heavy metals, mast cell activation, and the environmental exposures most doctors never think to test for.
More Patient Stories & Lectures
More on MCAS, plus the full library of patient stories and lectures from my YouTube channel.
Patient Success, Interviews, Lectures & More
What patients say
I’ve helped many patients get an accurate MCAS diagnosis after years of being dismissed — and find real, lasting relief. Read more patient stories and reviews on the testimonials page.
What a visit costs
I run an independent, cash-pay practice — no insurance billing, no pressure to fit your visit into a 10-minute slot. You can request reimbursement from your insurer using a superbill I provide after each visit.
Initial Visit
$700
45 minutes
Focused on your history, current labs and medications, and a plan for what to test next.
Extended Initial
$950
2 hours
Ideal if you’re traveling to establish care, have a complex history, or want more time to go deep.
Follow-Up
$350
45 minutes
Most patients follow up every 4 weeks as we work through each part of the plan.
Not sure if I'm a fit?
Book a free 15-minute discovery call to ask questions before you commit to a visit.
MCAS questions, answered
How is MCAS actually diagnosed?
MCAS is diagnosed from a pattern of recurrent symptoms across multiple body systems, together with your history and, when appropriate, lab testing for mast cell mediators. It's a clinical picture, not a single blood test — which is why it's so often missed.
Is MCAS the same as a histamine intolerance or a food allergy?
They can overlap, but they're not the same. MCAS involves mast cells releasing multiple mediators — not just histamine — and can cause reactions to foods, chemicals, temperature, and stress that wouldn't show up on a standard allergy panel.
Is mold really connected to MCAS?
For many patients, yes. Chronic exposure to mold and water-damaged buildings is one of the most common triggers I see behind MCAS, and identifying and addressing that exposure is often a key step in getting well.
Do I have to stay on a strict low-histamine diet forever?
No. A low-histamine diet is typically used as a short-term tool to calm symptoms and identify triggers, not a permanent restriction. As we address the underlying drivers, most patients are able to broaden their diet again.
I've been told my symptoms are "just anxiety" — could it really be MCAS?
It's a common and frustrating experience for MCAS patients. Physical symptoms like flushing, GI upset, and reactive episodes have a real physiological cause, and I take the time to look for it rather than defaulting to a psychiatric explanation.
Do you accept insurance?
I don't bill insurance directly, but I provide a superbill after each visit that you can submit for out-of-network reimbursement. Working this way gives me the time and freedom to treat you as an individual, not a diagnosis code.
Have a broader question about my practice? Visit the full FAQ page.
Ready to find out what's really driving your MCAS?
Let’s Get Started
A doctor who cares about science
Working as an independent physician gives me time to study and keep learning new ways to help my patients. I’m proud to have contributed to our understanding of the gut–thyroid axis in a paper published in 2022.
I graduated from Tulane University School of Medicine and School of Public Health in 2011 and completed my Family Practice training in 2014. I treat many conditions, with particular expertise in GI health and mold and heavy-metal toxicity. When I’m not with patients, you’ll find me playing with my three kids, exercising, meditating, or playing the drums.
