Alphabet Soup that is Mast Cell Disorders

Once you’ve racked up enough diagnoses and spent enough time in hospitals the lingo starts piling up and it can get confusing but I held on. Until I got to mast cell disorders and mmmaaannn it is alphabet soup up in here. MCAD, SM, ASM, IgE, HSCs, H, UFH, DAMPs, PAMPS, ATP, TNF, and more! The good thing is you could read one article about this stuff, memorize it and sound REALLY smart rattling it back off at some party. Furthermore, mast cell disorders are not well known, relatively newly discovered, and effect each patient differently. Simple right?

So here is my attempt to spell (badumchh) it out for you guys. If you haven’t already, read my intro posts to mast cells here.

Types of Mast Cell Disorders 

• Mastocytosis (rare)
  • Cutaneous Mastocytosis
  • Indolent Systemic Mastocytosis
  • Systemic Mastocytosis with clonal hematologic non-mast cell lineage disease
  • Systemic Smoldering Mastocytosis
  • Aggressive Systemic Mastocytosis
  • Mast Cell Leukemia 
  • Mast Cell Sarcoma
• Mast Cell Activation Disorder (MCAD)
  *note: Mast Cell Activation Disorder and Mast Cell Activation Syndrome (MCAS) are the SAME disorder BUT they are not the same as the term “Mast Cell Disorders” which is an umbrella term for Mastocytosis and MCAD*

Difference between Systemic Mastocytosis (SM) and Mast Cell Activation Disorder (MCAD)

*note again: I don’t know enough about other forms of mastocytosis to formulate anything useful*

When looked at basically, the main difference between SM and MCAD is MCAD patients have the normal amount of mast cells in their bodies, they are just hyperactive and hypersensitive vs SM patients have too many mast cells throughout their bodies and they build up in various organs and cause issues. Symptoms of both can be identical and like most conditions, follow a spectrum from mildly affected to severely affected and can easily be life-threatening. High risks for both include anaphylaxis, severe bleeding from heparin release, seizures, organ damage from mast cell accumulation, even multiple system failure in severe cases. 

Common Treatments and Therapies

*note: I do not know of everything, this list is by no means exhaustive*

• H1 Antihistamines (stabilize one type of histamine, mainly hives, headaches, nausea): hydroxyzine HCl (Atarax), diphenhydramine (Benadryl), cyproheptadine (Periactin), cetirizine (Zyrtec), levocetirizine (Xyzal), fexofenadine (Allegra), loratadine (Claratin), desloratadine (Clarinex)
• H2 Antihistamines (stabilize a different type histamine, mainly GI): famotidine (Pepcid), Nizatidine (Axid), Ranitidine (Zantac)
• Mast Cell stabilizers: cromolyn sodium (Gastrocrom), quercetin, luteolin, asprin (if allowed)
• Leukotrine Inhibitors (respiratory): montelukast (Singulair), zafirlukast (Accolate), zileuton (Zyflo)
  *if you don’t feel like these are fictional sci-fi names by now… just wait*
• Xolair (omalizumab): this is an injection that was originally marketed for asthma but works to desensitize the body. Must be taken at an office every time, can be very expensive and hard to get covered by insurance, can have different reactions at different times. That being said I know people who have had amazing results from it
• Epinephrine injection (EpiPen & AuviQ) for anaphylaxis or anaphylactoid reactions
• Diphenhydramine injection (Benedryl IV/IM) for those who react poorly to epi or as a first response for reactions or if patient can’t take oral medications

All right folks. Think that’s enough to chew on for now. More later to come later!