Mastocytosis is a group of rare disorders of both children and adults caused by the presence of too many mast cells (mastocytes) and CD34+ mast cell precursors in a person's body. It can affect just the skin or it can also affect internal organs such as the stomach and intestines.

Some of the possible symptoms of mastocytosis look a lot like food or environmental allergies. A person with mastocytosis may be convinced that they have food allergies but the antibody tests may be negative.

* Itching
* Rashes
* Abdominal cramping
* Anaphylaxis (shock from allergic or immune causes)
* Skin lesions
* Abdominal discomfort
* Episodes of very low blood pressure (including shock) and faintness
* Bone or muscle pain
* Nausea and vomiting

Patients with Mastocytosis may feel better when taking reflux meds. Proton pump inhibitors help reduce production of gastric acid, which is often increased in patients with mastocytosis.