When your skin keeps reacting and no one can say why.
Mast Cell Activation Syndrome is one of the most missed diagnoses in medicine. It takes an average of ten years and a dozen specialists before it is named. Dr. Francesca Lewis and Dr. Avianne Hospedales evaluate and treat MCAS at Delray Skin, combining board-certified dermatology with integrative and longevity medicine.
Every visit scores the same symptom set, so your progress is graphed, not guessed.
What Mast Cell Activation Syndrome is
Mast cells are immune cells that live in your skin, gut, airway, and around your blood vessels. They are the body’s first responders. They release histamine, tryptase, prostaglandins, and dozens of other mediators to fight threats.
In MCAS, the number of mast cells is normal, but they are chronically over-reactive. They fire at the wrong things (heat, exercise, alcohol, fragrance, stress, certain foods) and they fire everywhere at once. That is why MCAS looks like a dozen unrelated conditions at the same time, and why the workup so often comes back “normal.”
Symptoms cross at least two organ systems (skin plus gut, airway, heart, or brain) and come in episodes.
Flares rise and fall around triggers, then settle. Between flares you may feel almost well, which is part of why it gets dismissed.
MCAS responds to mast-cell-directed therapy. Most patients see meaningful change within the first two to three months.
Fifteen body systems, one underlying cause
The inventory we use in clinic covers 84 symptoms across these systems. No one has all of them, but a pattern that spans several, and moves with triggers, is the signature.
Fatigue · flushing · migrating itch · sensitivity to scents, chemicals, or foods · night sweats · poor wound healing
Hives · dermatographism (skin that welts when scratched) · angioedema · recurrent rashes · easy bruising · eczema-type dryness
Nasal congestion · dry or irritated eyes · tinnitus · post-nasal drip · recurrent ear inflammation
Throat tightness · mouth sores · burning mouth · metallic taste · dental decay despite good care
Swollen or tender nodes that come and go · mild left-upper abdominal fullness
Shortness of breath · air hunger, cannot get a deep breath · cough · wheezing · disrupted breathing in sleep
Palpitations · lightheadedness on standing · blood pressure that swings · non-cardiac chest pain · migrating edema
Nausea · migrating abdominal pain · alternating diarrhea and constipation · bloating · new food intolerances · reflux
Bladder pain or urgency with negative cultures · pelvic pain · painful or irregular periods · vulvar discomfort
Migrating joint, muscle, or bone pain · hypermobile joints · fibromyalgia-type pain · low bone density
Brain fog · headaches or migraines · dizziness · tingling or numbness · non-restorative sleep · tremor
Anxiety · panic episodes · irritability · mood swings · difficulty concentrating
Thyroid abnormalities · blood sugar swings · abnormal lipids · electrolyte and nutritional deficiencies
Anemia · iron deficiency · elevated eosinophils · easy bruising or bleeding · clotting tendency
Allergic and hypersensitivity reactions · frequent infections · slow healing · autoimmune tendencies
Could this be mast cell activation?
Check anything you have experienced in the past six months. Nothing is stored or sent. This is a private, instant read on whether your pattern is worth evaluating.
The skin usually tells us first
More mast cells live in the skin than in almost any other organ. That is why the earliest and most visible signs of mast cell disease are dermatologic: the flushing, the hives that appear and vanish, the welt that rises where you scratched, the swelling of a lip or eyelid overnight.
Patients are often sent from gastroenterology to cardiology to allergy and back, while the diagnosis is quietly written on their skin. A dermatologist who knows what to look for can provoke dermatographism in ten seconds at the exam table.
How we work it out
MCAS is a clinical diagnosis supported by laboratory evidence. There is no single test that settles it, which is exactly why a structured, unhurried evaluation matters.
History & symptom inventory
A full 84-symptom inventory across 15 systems, scored 0–10. It takes about fifteen minutes and it maps the pattern before you ever get to the exam table.
Skin-directed examination
Dermatographism provocation, urticaria and angioedema assessment, Darier’s sign, telangiectasias, and evaluation for cutaneous mastocytosis.
Mediator testing
Serum tryptase, ideally baseline and within four hours of a flare, plus 24-hour urinary N-methylhistamine, prostaglandins, and leukotriene E4, with the handling instructions labs so often get wrong.
Rule-outs & overlap
Thyroid, tryptase genetics (hereditary alpha-tryptasemia), carcinoid, and the frequent travelling companions: POTS, hypermobile Ehlers-Danlos, and small-fiber neuropathy.
Response to therapy
The third consensus criterion. We score the same symptoms at every follow-up, so improvement on mast-cell-directed treatment is measured rather than remembered.
Episodic multi-system symptoms consistent with mast cell mediator release · objective evidence of mediator elevation · documented response to mast-cell-directed therapy.
What we bring to the problem
Treatment is layered and personal. We start with the foundation, then add only what your response tells us to add, and we measure at every step.
Testing done properly
Baseline and flare-state tryptase, 24-hour urinary mediators with chilled handling, CBC with differential, and screening for the conditions MCAS travels with.
H1, H2, and stabilizers
Layered antihistamine blockade, mast cell stabilizers such as cromolyn and ketotifen, leukotriene modifiers, and a written rescue plan you carry with you.
Low-histamine guidance
A structured elimination and reintroduction plan, restrictive enough to learn something, brief enough to protect your nutrition and your life.
Infusion support
In-studio hydration and nutrient infusions for patients whose absorption, volume status, or deficiencies are not correctable by mouth.
Clean formulations
Quercetin, vitamin C, DAO enzyme support, and compounded preparations free of the dyes, binders, and preservatives that set reactive patients off.
Finding the pattern
Heat, exercise, alcohol, fragrance, mold, hormones, stress. We map yours against your scores instead of asking you to avoid everything.
The right specialists
Allergy and immunology, gastroenterology, hematology, and clinicians in South Florida who actually understand POTS and hypermobile Ehlers-Danlos.
Handouts you can use
Trigger and low-histamine food guides, a flare action plan, a procedure and anesthesia precaution sheet, and a summary letter for your other physicians.
Organizations we point to
The Mast Cell Disease Society (TMS), the American Academy of Allergy, Asthma & Immunology, and the international consensus criteria we practice by.
Two physicians who take this seriously
Where the scoring happens
Two different things, and it is worth knowing which one applies to you.
Start with the self-check
Two minutes, right here on this page. Nothing stored, nothing sent. It tells you whether your pattern is the multi-system, episodic picture worth bringing in.
Take the self-checkPre-visit scored inventory
Before your visit we send your symptom inventory through Klara, the secure messaging service you already use with us. Watch for it a few days ahead, and bring it or complete it in the room.
Prefer paper? Ask the front desk and we will post one to you, or have it waiting at your appointment.
Your answers go only to your care team and become part of your chart. A symptom inventory is a tracking tool, not a diagnosis. Severe reactions (throat swelling, trouble breathing, fainting) are an emergency: call 911.
What the first appointment actually looks like
Before you arrive
Complete the inventory and gather prior labs, biopsy reports, and the list of everything you have already tried.
Sixty minutes, unhurried
We go through the pattern together, then examine the skin. You will not be rushed and you will not be told it is anxiety.
You leave with a plan
Lab orders, a starting medication layer, trigger guidance, and a rescue plan in writing, on day one, not after the results.
Four to six weeks later
We re-score the same symptoms, read the labs against them, and adjust. That comparison is the diagnosis working.
Frequently asked questions
Is MCAS a real diagnosis?+
Yes. Mast cell activation syndrome appears in the World Health Organization’s classification of mast cell disorders and has published international consensus criteria. It is newer and less familiar than many conditions, which is why patients so often meet clinicians who have not evaluated one, but it is a recognized disease, not a theory.
My tryptase was normal. Does that rule it out?+
No. A normal baseline tryptase is common in MCAS. What matters more is whether tryptase rises during a flare compared with your own baseline, and whether other mediators (urinary N-methylhistamine, prostaglandins, leukotriene E4) are elevated. Timing and specimen handling are the two places these tests usually go wrong, and both are fixable.
How is MCAS different from mastocytosis or ordinary allergies?+
In mastocytosis there are too many mast cells. In MCAS the number is normal but the cells are over-reactive. Classic allergy is an IgE-mediated response to a specific allergen; MCAS reactions are frequently non-IgE and triggered by things allergy testing cannot capture: heat, exercise, alcohol, fragrance, stress, hormonal shifts. It is entirely normal to have MCAS and a clean allergy panel.
Why a dermatology practice?+
The skin holds one of the densest populations of mast cells in the body, and skin findings are usually the first visible evidence of the disease. Dermatology is also where hives, flushing, and unexplained swelling land after every other door has been tried. Pairing that with integrative medicine covers both the reaction and everything feeding it.
How long until I feel better?+
Many patients notice a difference within a few weeks of getting the antihistamine layer right. Building a full regimen (stabilizers, nutrition, trigger control, deficiencies corrected) typically takes three to six months of adjustment. We re-score your symptoms at every visit precisely so that progress is visible even when it is gradual.
Do I have to give up most foods?+
No. A low-histamine trial is a short diagnostic instrument, not a life sentence. We use a defined elimination window and then reintroduce systematically, so you end up with the shortest possible list of real triggers rather than a permanently shrinking diet.
Can I still have cosmetic treatments?+
Usually yes, with planning. Lasers, heat, certain topicals, and some injectables and anesthetics can provoke mast cells, so we pre-medicate, patch test where it makes sense, and sequence treatments once you are stable. Being treated for MCAS in the same studio that does your aesthetics is a genuine advantage here.
Is the evaluation covered by insurance?+
The MCAS evaluation at Delray Skin is self-pay. That is what lets us give you a full hour and build the plan around the whole picture rather than around what a billing code will cover. You will have clear pricing before you book, so there are no surprises.
You have been describing this to doctors for years. Come describe it once more.
Bring the inventory. We will read it before you arrive.
Delray Skin · 1120 S Federal Hwy, Ste 200, Delray Beach, FL 33483
Tell us where to reach you
A member of the team will call you back. If you took the self-check above, mention what it said and we will have it in front of us.
The information on this page is for education and does not replace a medical evaluation. Patient-reported screening tools are not a diagnosis. If you are having trouble breathing, throat swelling, or a severe reaction, call 911.
