Treatment

The treatment options for mastocytosis depend on which type you have and how severe your symptoms are.

Nearly all medicines used to treat mastocytosis are unlicensed. This means the manufacturers haven't applied for a licence for their medicine to be used to treat mastocytosis.

In other words, the medicine has not undergone clinical trials to see if it can treat mastocytosis effectively and safely.

Many experts will use an unlicensed medicine if they think it will be effective and the benefits of treatment outweigh any associated risk.

Midostaurin

Midostaurin is a licensed medicine that can be used to treat advanced systemic mastocytosis. It works by slowing down the growth of mast cells.

It can help to relieve some symptoms of advanced systemic mastocytosis and improve quality of life.

Side effects of taking midostaurin might include:

• diarrhoea and vomiting
• chills
• headaches
• weight gain

Steroid cream

Mild to moderate cases of cutaneous mastocytosis can be treated with a very strong steroid cream (topical corticosteroids) for a limited length of time.

Steroid cream reduces the number of mast cells that can release histamine and trigger inflammation inside the skin.

Side effects of steroid cream when used too much include:

• thinning of the skin, which can sometimes result in permanent stretch marks
• a temporary reduction in the pigmentation of the skin
• the affected area of skin bruising easily

You should only apply the cream to areas of skin affected by lesions to reduce the risk of side effects.

Antihistamines

Antihistamines can also be used to treat symptoms of cutaneous or indolent mastocytosis, such as itchiness and skin redness.

Antihistamines are a type of medicine that block the effects of histamine. They're widely used to treat allergic conditions.

Side effects of some "classical" antihistamines include:

• headache
• dry mouth
• drowsiness

However, these side effects should pass quickly once you're used to the medicine. Modern antihistamines do not usually cause these side effects.

Sodium cromoglicate

Sodium cromoglicate is a medicine used to treat conjunctivitis, asthma and food allergy. It may also be used to treat gut symptoms of mastocytosis, but is not absorbed well from the bowel.

Sodium cromoglicate is a mast cell stabiliser, which means it reduces the amount of chemicals released by the mast cells. This helps relieve symptoms such as diarrhoea and stomach pain.

Some people taking sodium cromoglicate have reported feeling sick and getting joint pain.

A form of sodium cromoglicate applied to the skin is available that may help with itching. However, it's not routinely available on prescription.

Psoralen plus ultraviolet A (PUVA)

More severe symptoms of cutaneous mastocytosis, such as severe itchy skin, may require a type of treatment called psoralen plus ultraviolet A (PUVA).

PUVA involves taking a medicine called psoralen, which makes the skin more sensitive to the effects of ultraviolet light.

The skin is then exposed to a wavelength of light called ultraviolet A (UVA), which helps reduce lesions in the skin.

You can only have a limited number of PUVA sessions as using the treatment too many times – around 150 sessions – may increase your risk of developing skin cancer over your lifetime.

Steroid tablets

If symptoms such as itchiness are particularly severe, corticosteroid tablets (oral corticosteroids) may be prescribed on a short-term basis. However, this is rare.

A short course of corticosteroid tablets may be recommended if you have bone pain caused by mastocytosis, or a severe allergic reaction (anaphylaxis).

Side effects of oral corticosteroids used on a short-term basis include:

• an increase in appetite
• weight gain
• insomnia
• fluid retention
• mood changes, such as feeling irritable or anxious

Bisphosphonates and calcium supplements

If you have weakened bones (osteoporosis) resulting from abnormal mast cell activity in your bones, you'll be given a medicine called bisphosphonates.

Bisphosphonates slow the process of bone breakdown while allowing production of new bone to continue as normal, which improves your bone density.

You may also be given calcium supplements, as calcium helps strengthen bones.

Read more about treating osteoporosis.

H2-receptor antagonists

If you have stomach pain caused by a stomach ulcer (peptic ulcer), you'll be given a medicine called an H2-receptor antagonist.

This blocks the effects of histamine in the stomach – histamine stimulates the production of stomach acid, which damages the stomach lining. 

Read more about treating a stomach ulcer.

Interferon alpha

Originally designed to treat cancer, interferon alpha has proved effective in treating some cases of aggressive mastocytosis.

It's not known exactly why this is, but it appears the medicine reduces the production of mast cells inside the bone marrow.

Interferon alpha is given by injection. You may have flu-like symptoms, such as chills, a high temperature and joint pain, when you start taking interferon alpha.

However, your symptoms should improve over time as your body gets used to the medicine.

Imatinib

Imatinib is an alternative medicine to interferon alpha. It's taken as a tablet and blocks the effects of an enzyme called tyrosine kinase, which helps stimulate production of mast cells.

However, imatinib should only be used for people who do not have the KIT mutation, and it does not work for most cases of mastocytosis.

Imatinib can also make you more vulnerable to infection. Contact your GP immediately if you develop possible signs of an infection, such as:

• a high temperature of or above 38C
• headache
• aching muscles
• diarrhoea
• tiredness

Nilotinib and dasatinib

Nilotinib or dasatinib may be recommended if you do not respond to treatment with imatinib. They work in much the same way, blocking the effects of tyrosine kinase.

The medicine will make you more vulnerable to infection, so report possible symptoms of infection to your GP immediately.

Cladribine

Cladribine was originally designed to treat cancer of the white blood cells (leukaemia), but it's also been shown to be useful in treating aggressive systemic mastocytosis. However, cladribine hasn't been approved (licensed) to treat mastocytosis.

Cladribine suppresses the activity of your immune system. It's given by infusion, which means it's slowly released into your body through a drip in your arm.

Like imatinib, nilotinib and dasatinib, cladribine will also make you more vulnerable to the effects of infection, so you should report possible symptoms of infection to your GP immediately.

Treatments for haematological disease

Systemic mastocytosis with associated blood (haematological) disease will be treated in the same way as aggressive systemic mastocytosis, with a number of additional treatments for the related haematological condition.

For more information about treating the most common haematological conditions, see:

Treating acute myeloid leukaemia

Treating chronic myeloid leukaemia

Treating acute lymphoblastic leukaemia

Treating chronic lymphocytic leukaemia

Treating Non-Hodgkin lymphoma

Treating multiple myeloma

Myeloproliferative neoplasms are also haematological disorders that can be associated with mastocytosis.

Using an adrenaline injection pen

Because of your increased risk of anaphylaxis, you may be given an adrenaline auto-injector to use in an emergency.

Adrenaline is a natural chemical that helps fight the effects of too much histamine, while also relieving breathing difficulties. Each pen contains a single dose of adrenaline.

There are 3 types:

• EpiPen
• Jext
• Emerade

These auto-injectors release adrenaline when jabbed or pressed against the outer thigh. The injections can be given through clothing.

If you're given an adrenaline auto-injector, you need to keep an eye on its expiry date because it will be less effective beyond this date.