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Symptoms of Mast Cell Activation

Updated On:
March 2024
David Harris

Mast Cell Activation Syndrome (MCAS) presents a broad spectrum of symptoms that can affect virtually any part of the body, complicating the path to a correct diagnosis. This condition involves the inappropriate release of mast cell mediators, leading to a wide array of manifestations ranging from mild to life-threatening. This article aims to shed light on the multifaceted symptomatology of MCAS, providing a clearer understanding of its impact on individuals.

Symptoms of Mast Cell Activation and Other Mast Cell Diseases:

Dermatological Manifestations

Skin-related symptoms are among the most visible signs of MCAS. Individuals may experience:

  • Pruritis: An intense itchiness that can lead to scratching and further skin damage.
  • Angioedema: Swelling beneath the skin, often around the eyes and lips.
  • Dermatographia: A condition where lightly scratching the skin causes raised, red lines.
  • Flushing and Hives: Sudden redness of the skin, accompanied by itchy and painful welts.

Respiratory Symptoms

Mast cell activation can significantly affect respiratory function, manifesting as:

  • Asthmatic Responses: Including wheezing and difficulty breathing.
  • Cough and Throat Swelling: Leading to a sensation of choking or difficulty swallowing.

Cardiovascular Issues

MCAS can influence heart and blood vessel functions, causing:

  • Chest Pain and Low Blood Pressure: Symptoms that can mimic heart disease.
  • Tachycardia and Arrhythmias: Abnormal heart rhythms that may cause palpitations or fainting.

Gastrointestinal Complaints

The digestive system is often severely impacted by MCAS, with symptoms including:

  • Gastroesophageal Reflux Disease (GERD): Acid reflux causing heartburn and discomfort.
  • Diarrhea and Abdominal Pain: Leading to significant discomfort and potential nutritional deficiencies.

Musculoskeletal Discomfort

Pain in the bones and muscles can be a distressing aspect of MCAS:

  • Widespread Pain: Often misdiagnosed as fibromyalgia.
  • Osteoporosis/Osteopenia: A reduction in bone density, increasing fracture risk.

Neurological and Cognitive Effects

MCAS can also affect the nervous system, resulting in:

  • Migraines and Brain Fog: Leading to difficulty concentrating and memory problems.
  • Anxiety and Depression: Psychological symptoms that compound the condition's impact.

Naso-ocular Symptoms

The nose and eyes are not spared, with common issues being:

  • Sinusitis and Nasal Congestion: Leading to chronic discomfort and breathing difficulties.
  • Watery Eyes: Often mistaken for allergies.

Systemic and Lymphatic Involvement

MCAS can trigger systemic reactions and affect the lymphatic system:

  • Fatigue and Weight Loss: Symptoms that significantly impact life quality.
  • Anaphylaxis: A severe, life-threatening allergic reaction that requires immediate medical attention.
  • Lymph Node Inflammation: Leading to discomfort and potential misdiagnosis of other conditions.

Transition to Anaphylaxis

A critical aspect of MCAS is its potential to escalate into anaphylaxis, a rapid onset allergic reaction that can be fatal. This transition underscores the necessity for prompt and effective management strategies to mitigate risks.


Understanding the diverse and often debilitating symptoms of Mast Cell Activation Syndrome is crucial for timely diagnosis and management. Given the complexity of MCAS, a multidisciplinary approach involving allergists, immunologists, gastroenterologists, and other specialists is essential for comprehensive care. Recognizing the signs and symptoms enables affected individuals and healthcare providers to implement strategies that can significantly improve patient outcomes and quality of life.


This article integrates findings from a variety of research studies and expert analyses on mast cell disorders. It highlights the critical importance of awareness, recognition, and medical oversight in managing the multifaceted symptoms of MCAS effectively.

  1. Mast Cell Hope. (n.d.). Overview of Mast Cell Diseases. Mast Cell Hope.
  2. Theoharides, T. C., Tsilioni, I., & Ren, H. (2019). Recent advances in our understanding of mast cell activation – or should it be mast cell mediator disorders? Expert Review of Clinical Immunology, 15(6), 639–656.
  3. Hamilton, M. J., Hornick, J. L., Akin, C., Castells, M. C., & Greenberger, N. J. (2011). Mast cell activation syndrome: a newly recognized disorder with systemic clinical manifestations. Journal of Allergy and Clinical Immunology, 128(1), 147-152.e2.
  4. Sarchio, S. N. E., Kok, L. F., O'Sullivan, C., Halliday, G. M., & Byrne, S. N. (2012). Dermal mast cells affect the development of sunlight-induced skin tumours. Experimental Dermatology, 21(4), 241-8.
  5. Boyden, S. E., Desai, A., Cruse, G., Young, M. L., Bolan, H. C., Scott, L. M., Eisch, A. R., Long, R. D., Lee, C. C., Satorius, C. L., Pakstis, A. J., Olivera, A., Mullikin, J. C., Chouery, E., Mégarbané, A., Medlej-Hashim, M., Kidd, K. K., Kastner, D. L., Metcalfe, D. D., & Komarow, H. D. (2016). Vibratory urticaria associated with a missense variant in ADGRE2. New England Journal of Medicine, 374(7), 656-63.
  6. Hamilton, M. J. (2018). Nonclonal Mast Cell Activation Syndrome: A Growing Body of Evidence. Immunology and Allergy Clinics of North America, 38(3), 469-481.
  7. Johansson, O., Gangi, S., Liang, Y., Yoshimura, K., Jing, C., & Liu, P. Y. (2001). Cutaneous mast cells are altered in normal healthy volunteers sitting in front of ordinary TVs/PCs--results from open-field provocation experiments. Journal of Cutaneous Pathology, 28(10), 513-9.
  8. An, S. Y., Hwang, E. K., Kim, J. H., et al. (2011). Vancomycin-associated spontaneous cutaneous adverse drug reactions. Allergy, Asthma & Immunology Research, 3(3), 194-198.
  9. Jennings, S. V., Slee, V. M., Finnerty, C. C., Hempstead, J. B., & Bowman, A. S. (2021). Symptoms of mast cell activation: The patient perspective. Annals of Allergy, Asthma & Immunology, 127(4), 407-409.
  10. Pal, S., Nath, S., Meininger, C. J., & Gashev, A. A. (2020). Emerging Roles of Mast Cells in the Regulation of Lymphatic Immuno-Physiology. Frontiers in Immunology, 11, 1234.
  11. Cruse, G., & Bradding, P. (2016). Mast cells in airway diseases and interstitial lung disease. European Journal of Pharmacology, 778, 125-138.
  12. Pardanani, A. (2016). Systemic mastocytosis in adults: 2017 update on diagnosis, risk stratification and management. American Journal of Hematology, 91(11), 1146-1159.
  13. Wang, Q., Lepus, C. M., Raghu, H., et al. (2019). IgE-mediated mast cell activation promotes inflammation and cartilage destruction in osteoarthritis. Elife, 8, e39905.
  14. Kounis, N. G., Mazarakis, A., Tsigkas, G., Giannopoulos, S., & Goudevenos, J. (2011). Kounis syndrome: a new twist on an old disease. Future Cardiology, 7(6), 805-24.
  15. American Academy of Allergy, Asthma, & Immunology. (n.d.). Anaphylaxis: Symptoms & Diagnosis.
  16. Fischer, D., Vander Leek, T. K., Ellis, A. K., & Kim, H. (2018). Anaphylaxis. Allergy, Asthma & Clinical Immunology, 14(Suppl 2), 54.
  17. Niggemann, B., & Beyer, K. (2016). Time for a new grading system for allergic reactions? Allergy, 71(2), 135-6.

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