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MCAS - Mast Cell Activation Syndrome
(MCAS)

 Histamine Intolerance
(HIT)

These are both underrecognized conditions but at MSGP Dr Ashby has taken a specialist
interest this area. MCAS occurs when the mast cell, an immune cell, behaves in a disordered way, and HIT occurs when there is an accumulation of histamine in the system.

​MCAS has only been formalised as a registered medical diagnosis in 2016, which is very recent in medical terms, but it is becoming more widely known through Long COVID.

Histamine Intolerance (HIT) can coexist with MCAS but is increasingly becoming recognised with increasing awareness of perimenopausal symptoms. This is
common time for HIT to become a health issue because of the similarities between the symptoms of perimenopause and HIT, making distinguishing the two challenging.


Dr Ashby’s women's hormone health work led her to develop a specialist interest in
HIT which has evolved into an MCAS specialism too.

Doctor and Patient

Some of the symptoms of Histamine Intolerance

☑️ Skin issues

 

☑️ Neurological Symptoms

 

☑️ Respiratory symptoms

 

☑️ Gastrointestinal issues

 

☑️ Cardiac symptoms

☑️ Urological and Sexual health symptoms

☑️ Worsening allergies or sensitivities

☑️ Musculoskeletal symptoms

45-minute appointment (£315) with Dr Clare Ashby for a detailed consultation to review, examine, discuss and plan treatment.

Before the appointment, we send a detailed questionnaire which will guide Dr Ashby at the appointment, enable her to understand and
process your health journey to date which we ask you to send back before your appointment.

Your consultation will include a thorough understanding of your health history, medication, sensitivities, any food, medication or environmental sensitivities. For those who are facing hormonal changes, it will also require an MSQ- a validated tool for assessing symptoms in perimenopause and menopause. 

There is a role for diagnostic testing in HIT and MCAS and this will be discussed. There are however challenges with testing for Mast Cell Medicators and histamine, they degrade readily and therefore the testing is complex. Dr Ashby will discuss this with you, and personalise suggestions according to your symptoms and discuss any important “rule out” tests, as necessary.

She will then review your questionnaire and discuss your concerns and health issues. She will then formulate a personalised management plan for you which consists of: 

● Dietary plan and recommendations 

● advice on recommended supplements 

● medical prescribing if required

Dr Clare Ashby.png

Dr Clare Ashby
BSc, BMBS, MRCGP

GP

Information will also be sent subsequently by email with further recommendations and details. Although 45 minutes sounds like a long appointment, there is much to discuss and review. This consult fee includes the cost of writing any prescriptions.

 

A follow-up appointment after 4 weeks is required, 45 minutes £280 

The follow-up appointment is to see how the patient has responded to the treatment so far and then to make adjustments and further changes if needed. 

Further information: 

● Certain supplements may be suggested and these can be purchased at the practice. 

● Other tests are sometimes requested 

● ECG £105 

● Bowel tests (faecal samples) £213

What is mast cell activation syndrome (MCAS)?

MCAS has only been formalised as a registered medical diagnosis in 2016, which is very recent in medical terms, but it is becoming more widely known through Long COVID. A condition called Histamine Intolerance (HIT) can co-exist with MCAS. This is a condition whereby the person is unwell because of an accumulation of histamine in their system. There can be a lot of overlap with HIT and MCAS and their management.

Recognition and diagnosis are essential to being the first step to helping. The essence of the treatment is to reduce how activated your mast cells are. Mast cells are like little water balloons containing histamine and other mediators that cause inflammation. Mast cells and histamine are a part of our immune system. An example of mast cells and histamine at work is when we are stung. Upon being stung we get a red swollen area, the swelling, redness, itch, pain and inflammation come from mast cells releasing histamine, and other mediators, into the tissue. This visual prompt helps you to imagine how mast cells and histamine can cause inflammation elsewhere in the body. 

MCAS patients have often suffered from mildly disordered mast cells for their whole life. Commonly with a back story of moderate health issues such as childhood asthma, eczema, recurrent tonsillitis, ear infections, food sensitivities, hayfever, migraine, IBS, period problems, unexplained fatigue or brain fog, intolerance to fragrances or perfumes to name a few. A patient does not need to have all of these, but more than two symptoms in 2 distinct organ systems would make one suspicious.

 

There is commonly a family history of similar health complaints. Then these patients can find they become more unwell after an acute infection or vaccine. Another big precipitant of disordered mast cells is exposure to mould in your environment. MCAS is associated with hypermobility, POTS and dysautonomia.

Doctor Using Digital Tablet
bhrt.png

Book your MCAS / Histamine Intolerance consultation

45 min
£315

MCAS can manifest itself differently in different patients.

 

Some of the symptoms:

Skin symptoms: rashes, hives, itchy skin, flushes after eating, reactions to bites, to name a few. 

Neurological symptoms: including headaches, migraine, brain fog, fatigue, anxiety and depression, insomnia, early morning waking feeling panicked. 

Respiratory symptoms: including chronic nasal congestion, chronic cough, sneezing, shortness of breath, hormonal asthma exacerbations. 

GI symptoms: including globus- the sensation of a fullness or presence in the throat, reflux symptoms, pain, cramping, bloating, diarrhea/ constipation, “food intolerances”, often the umbrella term of IBS has been given to a patient. 

Cardiac symptoms: including palpitations, chest pains, POTS, syncope (faintness) 

Urological and Sexual health symptoms: bladder pain syndrome (for men too), chronic pelvic pain, menstrual pain, heavy menstrual bleeding, vaginal irritation after intercourse, “recurrent UTIs” but that do not show an infective organism upon testing.

There is a working school of thought MCAS may have a role in endometriosis and recurrent miscarriage. 

Worsening allergies or sensitivities: 

Including noticing you are becoming more sensitive to your environment; this can include things like feeling unwell or headaches with exposure to scented candles or air fresheners/ cleaning products/ washing powders/ fabric softeners. Noticing worsening hay fever. 

Musculoskeletal symptoms: muscle and joint pains and fatigue.

Unfortunately testing for Histamine intolerance and MCAS has complexities. The tests we have available test for 10 of the 1200 mast cell mediators. There are technical challenges to the testing- the samples need to be kept cold from the moment of collection to when the sample is processed.

 

The testing only occurs in a few specialist laboratories. It can be appropriate to make a clinical diagnosis and commerce a trail of treatment and review for symptom improvement, thus supporting the clinical diagnosis. There may be a role for testing with “rule out” tests to ensure no other concerning pathology is overlooked. 

Dr Ashby has created a community of specialist nutritionists and functional medics whos expertise can further assist patients who may want support with nutrition advice, dysbiosis testing and treatment and mold testing and treatment. 

MCAS and HIT treatment needs to be personalized and tailored to the individual's symptoms. The treatments are commonly based on a ladder approach and commonly use nutraceuticals and medications while also considering adjuncts to health and healing such as photomodulation: red light therapy and Limbic Retraining. HRT needs to be considered in the context of MCAS and HIT as it requires a specialist consideration. Dr Ashby will be able to advise on this.

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