Children with mastocytosis have extra mast cells, a normal type of cell that we all have that release histamine and other chemicals when activated.
As you can imagine, having too many mast cells, which release too much histamine, isn’t a good thing.
What Causes Mastocytosis?
Mastocytosis, some forms of which have been known since 1869, is caused by spontaneous mutations that aren’t passed on to future generations (somatic mutations).
“Most forms of mastocytosis are caused by a mutation of the KIT gene on the 4q12 chromosome – a mutation that increases cellular reproduction. The c-KIT gene mutation creates an overgrowth of one cell line of mast cells.”
What is mastocytosis?
And the symptoms you have with mastocytosis depends on the type you have, which can include localized (solitary, maculopapular cutaneous, diffuse cutaneous) vs systemic mastocytosis.
“The severity of the symptoms associated with mastocytosis may vary from mild to life-threatening. In general, symptoms occurring in mastocytosis are mainly due to the release of chemicals from the mast cells and thus produce symptoms associated with an allergic reaction.”
Mastocytosis – Rare Disease Database
Localized mastocytosis is usually present at birth or early infancy.
Do Vaccines Cause Mastocytosis?
Since it is caused by spontaneous mutations and is often present at birth or early infancy, there is no reason to think that vaccines could cause mastocytosis.
Vaccines and Mastocytosis
That’s not to say that you shouldn’t think about vaccines if your child has mastocytosis.
Although almost anything can be a trigger for kids with mastocytosis, from insect stings, skin rubbing, antibiotics, aspirin, cough medications, exposure to heat or cold, and stress, there have been a few reports of vaccines being a trigger.
“In childhood, the risk for anaphylactic episodes was limited to children with extensive skin disease, but nonexistent for children with mastocytoma or limited macular lesions. This is in good agreement with the literature, where children with anaphylaxis were described as having clinically severe skin involvement of mastocytosis, although the levels of skin involvement were not given and tryptase concentrations not determined. Children with fatal anaphylaxis, described in three case reports, all had suffered from extensive blistering skin disease…”
Brockow et al on Anaphylaxis in patients with mastocytosis: a study on history, clinical features and risk factors in 120 patients.
It is important to note that these are kids with severe disease though and not the more typical type of localized disease that the average child will have.

It should also be noted that viral and bacterial infections with fever, some of which are vaccine preventable, can also be a trigger.
Still, if your child has extensive skin disease, your specialist will likely talk about premedication before vaccines and watching your child closely afterward in case they have an anaphylactic reaction.
Should they get fewer vaccines at a time?
Surprisingly, it depends on who you ask, but it should be noted that all of the discussions about vaccines are for kids with diffuse cutaneous mastocytosis (DCM), a rare form of cutaneous mastocytosis.
“Although patients with mastocytosis can be vaccinated according to the standard schedule, precautions to prevent MC activation and degranulation have been formulated by experts, particularly in cases of diffuse skin manifestations”
And none say to skip vaccines, although some say to use an alternative immunization schedule, getting one vaccine at a time perhaps, especially for the initial doses.
It should be clear that kids with mastocytosis can and should be vaccinated though and vaccines do not actually cause mastocytosis.
More on Vaccines and Mastocytosis
- What is mastocytosis?
- Mastocytosis – Rare Disease Database
- What are Mast Cell Disorders?
- Mastocytosis
- Systemic mastocytosis
- Visual Guide to Skin Lesions in Mast Cell Disorders
- Mast Cell Disorder Emergency Room Protocol
- Medical and Research Centers that Treat Patients with Mast Cell Diseases
- WHO – Anaphylaxis
- Medical Management of Vaccine Reactions in Children and Teens
- Study – Anaphylaxis in patients with mastocytosis: a study on history, clinical features and risk factors in 120 patients.
- Study – Increased serum baseline tryptase levels and extensive skin involvement are predictors for the severity of mast cell activation episodes in children with mastocytosisDiffuse Cutaneous Bullous
- Mastocytosis and Disseminated Intravascular Coagulation Postvaccination: A Case Report.
- Generalized bullous eruption after routine vaccination in a child with diffuse cutaneous mastocytosis.
- Routine Vaccinations in Diffuse Cutaneous Mastocytosis.
- Study – Vaccination management in children and adults with mastocytosis.
- Study – Paediatric mastocytosis: a systematic review of 1747 cases.
- Study – Mastocytosis in children and adults: clinical disease heterogeneity.
- Mastocytosis: a mutated KIT receptor induced myeloproliferative disorder
- Mast cell activation syndrome and the administration of influenza vaccine
- What is the risk of anaphylaxis after vaccination in children and adults?