Urticaria and Mastocytosis Dan Flashcards
T/F
Angioedema is itchy
False
painful not itchy
What is the definition of chronic urticaria?
more than 6 weeks duration
continuous urticaria occurring at least twice a week off treatment
What are the causes and mimics of acute urticaria?
Causes; Primary/Idiopathic 50% Secondary causes; Infection Drug eruption Contact urticaria Inhaled allergen urticaria Non immune drug/food urticaria Scombroid fish poisoning Serum sickness-like rcn
Mimics; AHOC SCLE EM, SJS onset of DH, Linear IgA, EBA PEP/PUPPP PMLE Sweets Neutrophilic eccrine hidradenitis Toxic erythemas
What are the causes and mimics of chronic urticaria?
Causes; Primary = Chronic Spontaneous Urticaria Secondary causes; Chronic infection AI disease Drug reaction Chronic inducible urticaria - MASTS Cutaneous mastocytosis
Mimics; Autoinflammatory syndromes Schnitzler’s syndrome Urticarial vasculitis Urticarial dermatitis Neutrophilic urticarial dermatitis Pre-bullous BP MF Eosinophilic dermatosis of haematological malignancy/ exaggerated insect-bite reaction Annular erythemas Wells syndrome
What are the major types of Inducible (physical) urticarias?
MASTS (as in mast cells) Mechanical Aquagenic urticaria Solar Urticaria Thermal Stress
What are the types of mechanical urticarias?
Dermatographism • Immediate Simple dermatographism Symptomatic dermatographism • Delayed dermatographism Delayed pressure urticaria Vibratory angioedema • Inherited • Acquired
What are the types of thermal urticarias?
Heat contact urticaria
Cold contact urticaria
• Primary
• Secondary (cryoglobulins, cryofibringen)
• Reflex
(Familial - autoinflammatory syndrome not an inducable urticaria)
What are the types of stress-induced urticarias?
Cholinergic urticaria Adrenergic urticaria Exercise-induced urticaria • Exercise-induced anaphylaxis • Food- and exercise-induced anaphylaxis
What are the histo findings of urticaria?
An invisible dermatosis Epidermis normal Dermal oedema Sparse perivascular and interstitial inflammatory infiltrate of eosinophils, lymphocytes, neutrophils, and/or mast cells Neuts +/- eos in vessels
What questions are important for screening for autoinflammatory disorders?
Any; Fevers malaise Joint pains NB consider delayed pressure urticaria or urticarial vasculitis also
T/F
Angioedema occurs in 50% of cases of urticaria
True
esp face, lips, eyelids etc
May also get mucosal swellings of oral cavity but usually not larynx
T/F
cow’s milk allergy is commonest cause of urticaria in infants under 6 months old
True
What are the causes of acute and chronic urticarias in young children?
Acute
Common reaction to URTI or other infection inc glandular fever (EBV)
Other acute causes – AHOC, scarlet fever, serum-sickness-like rcn, drug rcn
Chronic
If chronic/recurrent think of Urticaria pigmentosa or food allergy - esp cow’s milk allergy
What are the major causes of acute urticarias and what proprtion of cases do they account for?
Does not include insect bites and stings responsible for many cases
Idiopathic 50%
Infection 40% esp URTI
Drugs 9% (several mechanisms)
Foods 1% (allergy or histamine releasers)
Others;
Inhaled allergens
- Grass pollens, mould spores, animal danders, house dust mites
Contact urticaria
- Food most common
- Latex
Which foods should be avoided if latex allergic due to cross-reactions?
Kiwi Chicks Like bananas and Avos Kiwi Chestnuts Lychees Bananas Avocado
Which foods cause most type 1 acute (contact) urticaria?
Fish, nuts, milk, crustaceans, spices, apples, peaches
Which foods cause direct histamine induced urticaria (non-allergic)?
histamine containing – cheese, fish, meat, tomatoes, pineapple, avocados
Esp fish with scombroid poisoning
histamine-releasing – strawberries, alcohol
What is Scombroid fish poisoning?
underprocessed tuna, mackeral where bacteria has generated histamine by histidine decarboxylase leading to acute uticaria, vomiting, diarrhoea
Which drugs cause urticaria?
Almost any drug can cause an urticarial eruption as a side effect (not type 1 allergy)
e.g.
Antibiotics, vaccines, radiocontrast media, antidepressants, antihypertensives, antihistamines (H1 and H2!), antifungals, antiplatelets, NSAIDS, OCP, HRT
Bleomycin, asparginase, cyclophosphamide, chlorambucil, daunorubicin
Imatinib, Nilotinib, Dasatinib
some cause true type 1 allergy and anaphylaxis
some cause anaphylactoid reactions via direct histamine release e.g.
Opiates (morphine, codeine)
Antibiotics (vancomycin ‘red man syndrome’)
Iodine based radiocontrast dyes
Aspirin and NSAIDs
Also alcohol
T/F
Antihistamines can cause urticarial drug eruptions
True
T/F
NSAIDs can cause urticarial drug eruptions either by an allergic side effect mechanism or direct histamine release effects
True
T/F
NSAIDs can trigger mast cell degranulation in mastocytosis but can also be used to treat mastocytosis
True
can reduce flushing due to anti-prostaglandin effects
Introduce catiously along with antihistamine esp if Hx of intolerance
What are the major causes of chronic urticarias and what proprtion of cases do they account for?
60% Primary chronic urticaria - Autoimmune - Pseudoallergic - food, drug - Infection-related - Idiopathic = chronic spontaneous urticaria 35% Inducible urticaria 5% Urticarial vasculitis
T/F, Regarding chronic spontaneous urticaria;
30%-50% due to activating IgG autoantibodies to alpha subunit of FcεRI (high affinity mast cell surface receptor), or less frequently against receptor-bound IgE
True
Cause of the remainder unknown but some may be unidentified Autoimmune, Pseudoallergic or Infection cases
T/F
Regarding Primary chronic urticaria;
Up to 60% are due to intolerance to dietary or drug pseudoallergens
False
Up to 30%
e.g. colouring agents, preservatives, antioxidants, flavour enhancers, aspirin
What factors can aggravate chronic urticarias?
Drugs esp Aspirin and other NSAIDs Histamine containing/releasing foods and drugs Dietary psudoallergens Infection e.g. URTIs Pressure Overheating Premenstrual periods Alcohol Stress Exercise Implants and nickel allergy
What must be excluded to make the diagnosis of chronic spontaneous urticaria?
Drug cause Pseudoallergen cause - food, drugs - colouring agents, preservatives, antioxidants, flavour enhancers, aspirin Autoimmune disease o Thyroid autoantibodies o Coeliac disease (in children and adolescents) o Pernicious anaemia o Vitiligo o SLE Occult infection o Dental abscess o Helicbacter pylori gastritis o Gastrointestinal candidiasis o strongyloides inducible urticaria (MASTS) - history and testing Alternative diagnoses/mimics; esp; Autoinflammatory syndromes Schnitzler’s syndrome Urticarial vasculitis Urticarial dermatitis Neutrophilic urticarial dermatitis Pre-bullous BP
T/F
chronic spontaneous urticaria is a diagnosis of exclusion
True
T/F
An extensive malignancy screen is prudent in chronic urticaria
False
No strong association
What is Episodic ordinary urticaria?
Urticaria occurring less frequently than twice per week over a long period; more likely to have an identifiable environmental trigger than chronic
What are the most common inducible urticarias?
o 9% dermographism
o 4% cholinergic urticaria
account for 13 of the 19% of all urticarias which are inducible
T/F
5% of normal people get dermographism
True
usually asymptomatic
Symptomatic dermographism is the most common physical urticaria
T/F
Symptomatic dermographism is worse at night and occurs in bouts
True
T/F
Symptomatic dermographism of the vulva occuring during sex can present as vulvodynia/vestibulodynia or dyspareunia
True
T/F
Symptomatic dermographism tends to improve over months
False
improves over years
What is Delayed dermatographism?
dermatographism which appears at least 30 mins after stroking stimulus
What is red dermatographism?
Response to repeated rubbing not stroking the skin
What is white dermatographism?
Feature of atopic dermatitis
What is cholinergic dermatographism?
Seen in some patients with cholinergic urticaria, whose dermographic response consists of an erythematous line studded with punctate weals characteristic of cholinergic weals
What is the delay in delayed pressure urticaria?
30mins-12 hrs after stimulus
Occurs under tight clothing (waistline, sockline of ankles, feet in tight shoes), palms after manual labour, buttocks/lower back after sitting, feet after walking or climbing ladders
Systemic features may occur (malaise, ‘flu-like’, arthralgias) which may be mistaken for urticarial vasculitis
T/F
delayed pressure urticaria persists lifelong
False
may resolve in 6-9 yrs
What are the features of Vibratory angioedema?
Type of inducible urticaria not true angioedema
Vary rare form of urticaria
Vibratory stimulus induces localised swelling and erythema within minutes, lasting 30 mins
Jogging, vigorous towelling, using lawnmowers
May be acquired or Inherited - AD
What are the features of heat contact urticaria?
One of the rarest forms
Within mins of contact with heat from any source, pruritus and whealing occur at the site of contact lasting up to 1 hr
Must be distinguished from cholinergic urticaria and solar uricaria
E.g contact with hot water (e.g. washing dishes), radiant heat or warm sunlight
What are the types of cold urticaria?
Primary
Secondary
Reflex
Familial (FCAS)
In primary cold urticaria, wheals occur when ice is applied to skin
False
Whealing occurs within minutes of rewarming after cold exposure
Test by application of an ice cube in a thin plastic bag for up to 20mins onto the skin and wealing occurs within 15 mins during rewarming
What are the features of primary cold urticaria?
common type of inducible urticaria
Dermographism and cholinergic urticaria are frequently associated
Whealing occurs within 15 minutes of rewarming after cold exposure
should warn against cold-water bathing due to risk of anaphylaxis and drowning
What is secondary cold urticaria?
Rare type of inducible urticaria
Due to serum abnormalities such as cryoglobulinemia or cryofibrinogenemia
associated with other manifestations such as Raynaud’s phenomenon or purpura
Exclude underlying causes such as Hep B/C, lymphoproliferative disease, or EBV
What is Reflex cold urticaria?
Widespread wealing occurs in response to cooling of core body temperature, but a local ice-cube test is negative
Dont test by cooling pt in freezer as risk of fatal anaphylaxis
What is Familial cold urticaria?
Now called Familial cold autoinflammatory syndrome (FCAS)
Rare type of cryopyrin-associated periodic syndrome
Patient has mutation in gene which encodes protein cryopyrin
AD, NLRP3 gene
symptoms onset at birth or shortly afterwards
Episodes triggered by cold but not locaised i.e. ice cube test negative; last about 24 hrs
several symptoms during episodes but figurate/urticarial rash present every time
Fever
Muscle pain (myalgia)
Joint pain (arthralgia) – 96%, stiffness and swelling of the hands and feet
Headache
Nausea
DrowsinessExtreme thirst
Eye – frequent conjunctivitis (84%), blurred vision, pain
What is Cholinergic urticaria?
common type of inducible urticaria
Occur within 15 mins of sweat-inducing stimuli (e.g. physical exertion, hot baths, sudden emotional stress, gustatory stimuli (spicy food), moving from cold room to a hot room, drinking alcohol)
Multiple small wheals on erythematous base
Cause of exercise-induced urticaria and sometiems anaphylaxis
Intradermal injection of nicotine, Ach or methacholine triggers the rash and is diagnostic
T/F
Cold urticaria, symptomatic dermographism, or aquagenic urticaria may be of cholinergic urticaria clinical type
True
small wheals
What is Adrenergic urticaria?
Rare type of inducible urticaria
Halo hives are characteristic - blanched vasoconstricted skin surrounding individual small pink wheals (‘halo hives’)
Due to Mast cell degranulation triggered by noradrenaline
Induced by sudden stress, trauma, emotional upset, chocolate, coffee, ginger
Can be wheeze, palpitations, SOB, paraesthesiae, malaise
IgE and serum catecholamines rise during episodes but histamine and serotonin are normal
Intradermal injection of adrenalin or NA (5-10ng each)triggers the rash and is diagnostic
Treat by avoiding triggers +/- oral propanolol up to 40mg TDS
(selective beta blockers are ineffective) complete response to propanolol in the correct clinical setting is probably sufficient to make the diagnosis
T/F
Propanolol is the only effective Rx for adrenergic urticaria
True
T/F
Serum histamine, IgE and serum catecholamines rise during episodes of adrenergic urticaria
False
IgE and serum catecholamines rise during episodes but histamine and serotonin are normal
T/F
Solar urticaria may be triggered by all types of UV light
True
T/F
Symptoms of solar urticaria appear after several hours of sun exposure
False
within minutes
T/F
Symptoms of solar urticaria fade after several hours out of sun exposure
True
usually 2 hrs
T/F
A quarter of cases of solar urticaria resolve in 10 years
True
15% at 5 yrs and 25% at 10 yrs
T/F
The eruption of aquagenic urticaria resembles that of cholinergic urticaria
True
T/F
Contact urticaria is always immunologically mediated
False Allergic (type 1, IgE mediated) and non-imminological types
What are the common causes allergic of conatct urticaria?
Latex Foods - Fish, nuts, milk, crustaceans, spices, apples, peaches Foods which cross react with latex - Kiwi Chicks Like bananas and Avos Kiwi Chestnuts Lychees Bananas Avocado
What are the common causes non-allergic of conatct urticaria?
Direct injection of vasoactive chemicals by plants (e.g. nettles) or animals (e.g. caterpillars, jellyfish)
Exposure to cosmetics (e.g. cinnamic aldehyde, balsam of Peru)
Food additive (e.g. sorbic acid or benzoic acid)
T/F
Episodes of anioedema usually settle within 24hrs
False
often do but can persist for hours or occasionally 2-3 days
Which drugs cause angioedema?
ACE inhibitors - most common
NSAIDs
Penicillins
T/F
Hereditary angioedema accounts for less than 5% of cases of angioedema without weals
True
T/F
Hereditary angioedema usually presents in childhood
True
75% present before puberty but some not until adult life
T/F
In Hereditary angioedema abdominal symptoms may occur in absence of skin changes sometimes presenting as an acute abdomen
True
also nausea, vomiting, colic and urinary symptoms
What are triggers for attacks in Hereditary angioedema?
trauma (emotional or physical) esp intubation, dental extraction etc
Oestrogens (OCP)
T/F
C3 is a good initial screening test for C1 esterase inhibitor deficiency (inherited and acquired)
False
C4 good test - investigate if LOW
Low in Types 1 and 2 HAE and in acquired angioedema
(but normal in rare type 3 HAE)
C2 and CH50 are also low during attacks and sometimes between attacks
T/F
Hereditary angioedemas are autosomal recessive
False
AD usually family history
25% new mutations
T/F
Pts with type 3 Hereditary angioedema have a later age of onset and higher frequency of facial angioedema compared to types 1 and 2
True
T/F
Type 1 Hereditary angioedema is due to reduced amount of C1 esterase inhibitor
True
80% of caes of HAE
T/F
Type 2 Hereditary angioedema is due to reduced function of C1 esterase inhibitor
True
Levels are normal