Anaphylaxis and Mastocytosis Flashcards
Classification of mast cells disorders
- Primary - MC more activatible either spont. or unknown trigger
- Secondary - MCs are activated by an ext. trigger like an allergen and antigens
MCAS definition (AAAAI)
A primary clinical condition with spont. episodic signs and symptoms of systemic anaphylaxis concurrently affecting two or more organ systems, resulting from secreted MC mediators
List the Anaphylaxis Criteria (WAO)
Criteria 1: Acute onset of illness involving skin/mucosal tissue with either a. resp sx or b. reduced BP
Criteria 2 - two or more of the following after exposure to a likely allergen
- skin/mucosal tissue
- resp sx
- reduced BP
- persistent GI sx
Criteria 3 - reduced BP after a known allergen
- in adults: <90 or 30%
What is Carmine allergy?
- red food dye
- from dried bodies of cost insects
- used in food like candy, ice cream etc
- confirm with skin testin
What is Anato allergy?
Yellow food colouring
- produced from fruit of a tropical annatto tree, Bixa orellana
Man develops anaphylaxis after eating a muffin and jumping into a pool, whats your ddx?
- FDEIA
- CIU
- EIA
- Local heat, cold or cholinergic urticaria
6 ways to differentiate exercise anaphylaxis vs cholinergic urticaria
- wheal size (cholinergic are small and pinpoint, EIA are larger)
- triggers - cholinergic triggers include warm baths, sweating, strong emotions
- Occlusive body suit test - CU have a drop in FEV1, EIA does not
- CU is responsive to hydroxyzine, EIA is not
- Hyperthermic blanket test or submersion into warm water
- Systemic symptoms are present in EIA not in CU
DDx for idiopathic anaphylaxis
- Food allergy - overlooked foods include spices, food containing aeroallergens, mislabeled foods, and food ingested with cofactors
- Medication allergy - NSAIDs
- Mast cell disorders
- Carcinoid syndrome
- Pheo
- CU
- Flushing reactions
- Restaurant syndromes: MSG, sulfites, scromboid
Work up for idiopathic anaphylaxis
- history and exam
- SPT, and rast
- tryptase, 24 hr urine histamine, 5-HIAA, VMA, and urinary catecholamines
- AI work up- lytes, TSH, T4
risk factors for severe anaphylaxis
- asthma
- CV disease
- mast cell disorder
- older age
- acute infections
- meds - BB, Alpha blocks, Acei
Criteria for mastocytosis
need 1 major and 1 minor OR 3 minor
Major
- presence of multifocal, dense mast cell infiltrates (>15 in aggregates in BM or other exogenous organs)
Minor
- > 25% mast cells spindle shaped or with abnormal morphology in bone or other exo organs
- detection of c-kit point mut at codon 816 in BM
- mast cells that co express CD117 with CD2 or CD25
- persistent serum tryptase> 20
Criteria for mast cell disorders
- Episodic multi system symptoms consistent with anaphylaxis
- Increase in validated markers of mast cell activation (serum or urine)
- response to medications that target mast cell activation syndrome
Classify mastocytosis
- systemic mastocytosis
- cutaneous mastocytosis
- solid organ tumours
pathogenesis of mastocytosis
- SCF (stem cell factor) is a growth factor which controls the production of mast cells
- this mutation is in KIT (CD117) receptor on codon 816 which is a receptor for SCF
- usually GOF CD 117
clinical features of mastocytosis
- dariers sign
- UP or MPCM
- diffuse cut. mastocytosis (DCM)
- mastocytomas
- telengectasia macularis eruptive perstand (TMEP)
- Anaphylaxis
- GI disturbance
- Neurophysiatric - mixed organic brain syndrome
- Heme
- MSK