Mastocytosis and Mast Cell Disorders

Authored by Dr Laurence Knott, 09 Jul 2017

Patient is a certified member of
The Information Standard

Reviewed by:
Dr John Cox, 09 Jul 2017

A mast cell is a type of white blood cell. Mastocytosis is a condition in which there are too many mast cells in the body, Another disorder involves a normal number of mast cells, but they are more active than normal.

You've basically got three main types:

  • Mastocytosis - there are too many cells.
  • Mast cell activation syndrome - there are normal numbers of cells but they zap around like hyperactive 2-year-olds. It's also sometimes called mast cell activation disorder.
  • Localised mast cell disorder - for reasons best known to themselves the mast cells hang around together in one place, drinking cider and making a general nuisance of themselves.

Anyone really, but it's pretty rare. It's seen in about 1 in 150,000 people. The skin type is mostly seen in kids. It can affect males and females equally.

It depends on the type.

Cutaneous mastocytosis

Cutaneous means skin. One of the most common skin problems caused by mastocytosis is urticaria pigmentosa. It starts in babies but can go on into the teens. It causes a rash anywhere on the body that looks like light brown, itchy raised patches. It can be associated with other allergy problems like anaphylaxis (a severe allergy reaction) and skin writing (dermographism). A less common skin condition is called diffuse cutaneous mastocytosis which looks like a very itchy rash with yellow skin. Large blisters can develop for no reason.

Localised mastocytosis

A red, brown or yellow lump can develop on the skin. This is called a mastocytoma. Very unusually, one of these lumps can be cancerous.

Systemic mastocytosis

Systemic is the word used in medicine to mean a generalised condition affecting most or all of the body. Symptoms depend on which parts of the body are involved. Common features include skin problems, tummy conditions, and disorders of the lungs and bones.

Read more about the symptoms of mastocytosis and mast cell disorders.

If I knew that I'd be writing this leaflet on a beach in the Bahamas rather than a patio in North London. It's thought to be inherited (a fault in genetic material), which means there's another thing you can thank your parents for.

It's known that symptoms can be triggered by a variety of factors, including temperature changes, rubbing, stress, foods, insect bites and various infections.

Learn more about the causes of mastocytosis and mast cell disorders.

A doctor may be able to guess the diagnosis of the cutaneous type from the appearance of your skin. However, many different conditions can produce similar symptoms, such as liver and bowel conditions, glandular disorders and rare tumours. Other skin complaints can also produce similar rashes. You're likely to need blood and urine tests, X-rays or scans and samples (biopsies) taken from your skin and bone marrow (the jelly-like substance inside your bones).

Find out more about the diagnosis of mastocytosis and mast cell disorders.

There are no wonder cures, but lots of medicines are available to help control symptoms. If you develop severe allergy reactions (anaphylaxis) you might have to carry one of these adrenaline (epinephrine) pens. Don't keep it in the same pocket as your e-cigarette or you'll be in for a big surprise. The good news is you'll be justified in wearing one of those cool medical emergency identification bracelets or similar.

Medicines are available for skin problems, disorders of your digestive system and wheezing. If the condition gets serious, there's some pretty heavy stuff available, including surgical removal of the spleen, bone marrow transplant and stem cell therapy.

Read more about the treatment of mastocytosis and mast cell disorders.

In most cases the condition either settles down or you get a few symptoms over the years that can be controlled by medication. The localised form just causes lumps that don't do very much but in rare cases they behave like little cancer tumours and invade the surrounding tissues. Occasionally, an aggressive form of the systemic condition can be life-limiting.

Learn more about the outlook (prognosis) of mastocytosis and mast cell disorders,

Further reading and references

  • Cardet JC, Akin C, Lee MJ; Mastocytosis: update on pharmacotherapy and future directions. Expert Opin Pharmacother. 2013 Oct14(15):2033-45. doi: 10.1517/14656566.2013.824424.

  • Maculopapular cutaneous mastocytosis; DermNet NZ, 2014

  • Pardanani A; Systemic mastocytosis in adults: 2017 update on diagnosis, risk stratification and management. Am J Hematol. 2016 Nov91(11):1146-1159. doi: 10.1002/ajh.24553.

Hello, I have a host of health issues that contribute to MCAD such as chronic lyme disease, mold exposure, POTS etc... I started having MCAD in August two days after starting some new antibiotics for...

Lynne845
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