Mastocytosis causes a wide range of symptoms, which can vary depending on the type of mastocytosis you have.

Cutaneous mastocytosis

Skin lesions are a characteristic of cutaneous mastocytosis. Types of lesions known to occur in cutaneous mastocytosis include:

small areas of skin that change colour (macules)

small firm, raised bumps (papules)

larger raised, red bumps (nodules)

large raised areas of skin noticeable to the touch (plaques)

blisters – which mainly affect young children with mastocytomas (tumours consisting of mast cells) or diffuse cutaneous mastocytosis (a rare form of cutaneous mastocytosis)

Lesions usually develop on the trunk rather than the head, neck and limbs.

The lesions, known as urticaria pigmentosa, are usually yellow-tan to reddish-brown in colour, and can range from 1mm to several centimetres in size.

The number of lesions that develop on the skin can vary widely. For example, it’s possible for only one lesion to develop, or more than 1,000.

Stroking the affected areas of skin can make it swollen, itchy and red over the lesion.

Systemic mastocytosis

If you have systemic mastocytosis, you may develop sudden episodes of symptoms that last for around 15-30 minutes. However, many people don’t have any problems.

The most common symptoms experienced during an episode are:

hot flushing – described as a dry feeling of heat, rather than the sort of wet heat you experience when sweating

a forceful or rapid heartbeat (heart palpitations)

dizziness (lightheadedness)

Less common symptoms during an episode include:

headache

shortness of breath

chest pain

nausea

diarrhoea

Once the episode has passed you’ll probably feel sluggish (lethargic) for several hours.

The episodes are caused by the mast cells suddenly releasing excessive amounts of histamine, usually after you’re exposed to certain triggers.

Triggers known to cause episodes include:

physical factors – such as heat, overheating, cold, fatigue and physical exertion

emotional factors – such as stress and excitement

insect bites or stings – such as flea bites or a wasp sting

infection – such as the cold or flu

alcohol

certain medications – such as ibuprofen, aspirin and antibiotics

certain foods – such as cheese, shellfish and spices

Abnormal mast cells in your bone marrow and organs can also cause related symptoms, including:

stomach pain caused by peptic ulcers

loss of appetite

joint pain

weakness

fatigue

changes in mental state – such as confusion, irritability, poor attention span and impaired memory

urinary symptoms – such as needing to pass urine frequently or pain when urinating

In more severe cases of mastocytosis, the following symptoms may occur:

weight loss

swelling of the lymph nodes

swelling of the liver – which can cause jaundice and make you feel lethargic

swelling of the spleen – which can cause tummy (abdominal) and shoulder pain

Low blood pressure (hypotension)

Some people with severe symptoms experience a sudden fall in blood pressure during an attack.

Low blood pressure (hypotension) can trigger a number of associated symptoms, such as:

dizziness

fainting

blurred vision

confusion

general weakness

Severe allergic reaction

If you have systemic mastocytosis or extensive cutaneous mastocytosis, your risk of a severe allergic reaction (anaphylaxis) is increased.

It’s important to look out for the initial symptoms of anaphylaxis, which include:

itchy skin or a raised, red skin rash

swollen eyes, lips, hands and feet

feeling lightheaded or faint

narrowing of the airways, which can cause wheezing and breathing difficulties

abdominal pain, nausea and vomiting

Dial 999 immediately and ask for an ambulance if you think you or someone else is experiencing symptoms of anaphylaxis.