Management of the peripartum period in a mast cell patient

I’ve been getting a lot of questions about pregnancy and delivery in mast cell patients. I had an interesting case a couple of years ago that I thought people might find illuminating. I contacted the patient and she had no problem with me sharing her case.

The case involved a pregnant mast cell patient experiencing both cardiovascular and mast cell driven complications of the pregnancy with significant risk of preterm delivery. I worked with the patient and her care team to develop a plan to minimize the risk of mast cell activation and anaphylaxis both before and after delivery. Mom delivered by Cesarean and had no complications during or after delivery. Baby also suffered no complications associated with birth.

This is some of the material I provided to her team.


Mast cell disease is a group of proliferative and non-proliferative conditions that is hallmarked by severe allergic reactions and anaphylaxis to triggers by non-IgE pathways. Due to the the diverse role of mast cells in many processes, including allergy, immune defense, wound healing and reproduction, mast cell degranulation and activation is an ever present threat.


Mast cell patients are recommended to premedicate prior to any procedure, including non-invasive procedures, to suppress mast cell activation.

24 hours before:
50mg prednisone

1-2 hours before:
50mg prednisone
50mg diphenhydramine
150mg ranitidine
10mg montelukast

An IV protocol used by some patients in place of the oral meds at 1-2 hours:
50mg diphenhydramine
40mg famotidine
40mg methylprednisolone

Following procedures/medical events/anaphylaxis, some patients do best with a taper of antihistamines and steroids to suppress rebound reactions and biphasic anaphylaxis in the following days. An example of this regimen is:

Antihistamine support:
-50mg diphenhydramine IV every 4 hours for first 24 hours
-50mg diphenhydramine IV every 6 hours for next 48 hours
-50mg diphenhydramine IV prn thereafter

Corticosteroid coverage:
Corticosteroids play an integral role in modulating mast cell activation. In the days following procedures/medical events/anaphylaxis, some patients do best with a steroid taper. Please note that the reason for the taper is NOT to prevent adrenal insufficiency, but to provide adequate steroid coverage to suppress mast cell reactions at a time when a non-mast cell patient would safely tolerate an abrupt cessation of steroids.

There is no defined protocol, but many patients use a Medrol dosepak or seven day prednisone taper following anaphylaxis and do well with this protocol following other procedures/events.

Cardiovascular concerns:

In cardiac patients with mast cell disease, Kounis Syndrome (allergic angina/MI) is a risk. In this condition, patients experience angina/MI as the result of a histamine driven process. Mast cell rescue medications (diphenhydramine, famotidine, methylprednisolone) should be given along with appropriate management of cardiovascular symptoms (nitroglycerin, calcium channel blockers). Epinephrine can be used if appropriate.

Beta blockers are a hard contraindication for mast cell patients as they interfere with the action of epinephrine. Use of beta blockers is commonly cited as a risk factor for fatal anaphylaxis. ACE inhibitors are often not recommended due to interaction with the angiotensin/renin system in which mast cells actively participate.

Pain management:

Most opiates are not recommended for mast cell patients due to induction of mast cell degranulation. Fentanyl and hydromorphone are the ones most often used successfully and are the drugs of choice for acute pain management.

Literature findings:

Ciach K, et al. Pregnancy and delivery with mastocytosis treated at the Polish Center of the European Competence Network on Mastocytosis (ECNM). PLoS One 2016; 11(1): e0146924

  • Five women delivered via cesarean. In one patient, the cesarean was performed specifically because of concerns about vaginal delivery in a mastocytosis patient. In the other four cases, cesarean was performed because of preeclampsia; improper positioning of the fetus; lack of labor progression; and large size of the fetus’ head relative to the size of the uterus. In all of these cases, spinal anesthesia was used with no complications.
  • Twelve women delivered vaginally without complications. In two patients, an epidural was used for pain management. In three patients, medication (oxytocin) was used to induce uterine contraction.
  • Four patients experienced pregnancy complications in the second trimester. The complications were pregnancy induced hypertension and swelling of the extremities; deep thrombosis (blood clot formation); toxoplasmosis, an infection; preterm labor without delivery; and vaginal bleeding in the first trimester.
  • Four patients delivered early, at 26 weeks, 36 weeks, and 37 weeks. The woman who delivered at 26 weeks had preeclampsia and her baby died less than a month after delivery due to extreme prematurity. Twelve patients delivered full term. Three babies had low birth weight upon delivery.
  • Mastocytosis patients are at higher risk of complications that involve clotting. Mast cell patients often experience coagulation irregularities, such as blood clot formation.
  • There have been three cases reported in literature of mastocytosis patients who developed preeclampsia that required preterm delivery.
    In order to suppress mast cell reactions and anaphylaxis, patients were premedicated before delivery with antihistamines and corticosteroids. Another study on pregnancy in mastocytosis reported that even with premedication, some patients still experienced mast cell activation during or after labor.
  • Epinephrine, antihistamines and glucocorticoids (steroids) should be readily available during and after labor

Matito A, et al. Clinical impact of pregnancy in mastocytosis: A study of the Spanish network on Mastocytosis (REMA) in 45 cases. Int Arch Allergy Immunol 2011; 156: 104-111.

  • 22% (10) of patients delivered via caesarean. 78% (35) delivered vaginally.
    Nine patients required labor induction. Oxytocin was used in eight cases and dinoprostone was used in one case.
  • Premedication for mast cell activation with antihistamines and glucocorticoids was only given to 38% (17) of patients.
  • 82% (37) of patients received anesthesia. 32 patients received epidurals; 3 received local anesthesia; and 2 received general anesthesia.
  • 11% of patients had mast cell activation symptoms, including flushing and itching, during or just following labor.

Dewachter P, et al. Perioperative management of patients with mastocytosis. Anesthesiology 2014, 12): 753-759.

  • Mastocytosis symptoms can improve, worsen, or remain unchanged during pregnancy.
  • Anesthesia management of mastocytosis patients has not been well described, with 13 CM patients and 33 SM patients mentioned in literature since 2000.
  • In one instance, IV epinephrine was necessary following labor to manage low blood pressure and difficulty breathing in an SM patient.
  • Early use of epidural anesthesia is recommended for mastocytosis patients to manage pain as pain triggers mast cell degranulation.
  • Patients should continue their regular medications to manage mast cell disease until the day of surgery.