Download MBBS Venereology and Leprosy Presentations 5 Urticaria and Angioedema Lecture Notes

URTICARIA

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&

ANGIOEDEMA

? Urticaria is characterized by transient skin or mucosal

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swellings due to plasma leakage.

? Superficial dermal swellings are wheals
? Deep swellings of the skin or mucosa are angioedema

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WHEALS

? Pruritic, pink/ red/pale

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swellings of the superficial

dermis

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? ? Initial flare
? Few millimeters to several

centimeters

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? Number: few to numerous.
? Hallmark : individual lesions

come and go rapidly, by

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definition, in general within 24

hours.

ANGIOEDEMA

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? Swellings occur deeper in the

dermis/subcutaneous/submucosal

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tissue.

? May affect the mouth rarely, the

bowel.

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? Involved areas : normal or faint

pink in color, rather than red

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? Painful rather than itchy,
? Larger and less well defined than

wheals

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? Often last for 2 to 3 days


1. Classic immediate

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hypersensitivity binding of

receptor-bound specific IgE by

allergen.

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? Others: stimuli that act through

the IgE receptor

2. anti-IgE and

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3. anti-FcRI antibodies
4. Non-immunologic stimuli:
opiates, C5a anaphylatoxin, stem

cell factor,some neuropeptides(e.g.

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substance P)
? cause mast cell degranulation by

binding specific receptors,

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independent of the FcRI


PATHOGENESIS

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? The mast cell is the primary effector cell of urticaria.
? Degranulation:
1. Cross-linking of two or more adjacent FcRI on the mast cell

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membrane

2. initiate a chain of calcium- and energy-dependent steps
3. fusion of storage granules with the cell membrane and

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externalization of their contents.
PATHOGENESIS

? Basic pathology - capillary permeability, allowing proteins and

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fluids to extravasate to the dermis.

1. Histamine and other proinflammatory mediators released on

degranulation ?

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Bind receptors on postcapillary venules in the skin ?
Vasodilation and increased permeability to large plasma proteins

(albumin and immunoglobulins).

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2. Histamine, TNF- and IL-8 upregulate adhesion molecules on

endothelial cells, promoting the migration of inflammatory cells

into the urticarial lesion.

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CLINICAL CLASSIFICATION OF

URTICARIA AND ANGIOEDEMA

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1. "Ordinary" (spontaneous) urticaria
2. Physical (inducible) urticarias
3. Urticarial vasculitis (vasculitis on skin biopsy)
4. Contact urticaria (induced by percutaneous or

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mucosal penetration)

5. Angioedema without wheals
6. Distinctive urticarial syndromes

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ACUTE vs CHRONIC URTICARIA

? All urticarias are acute initially
? "Chronic urticaria": usually defined as 6 weeks or more.

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Applied to continuous urticaria occurring at least twice

a week off treatment for 6 weeks

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? Urticaria occurring 6 weeks is called episodic / recurrent


ASSOCIATIONS OF CHRONIC URTICARIA

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? Autoimmune thyroid disorders
? Vitiligo
? Insulin dependent diabetes
? Rheumatoid arthritis
? Pernicious anemia

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? Helicobacter pylori gastritis
? Intestinal strongyloidiasis(endemic countries)
? ?Dental infections or gastrointestinal candidiasis

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CLASSIFICATION OF PHYSICAL

URTICARIA

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CLASSIFICATION OF PHYSICAL

URTICARIA

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CLASSIFICATION OF PHYSICAL

URTICARIA

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URTICARIAL VASCULITIS

1. Favors middle-aged women
2. Urticarial lesions >24 hours in duration;

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painful & burning sensation as well as

pruritus;

3. Residual purpura as they resolve

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4. Sites: often occur at pressure points
5. Concurrent angioedema :up to 40% of pts
6. Disease course: average of 3 years
EXTRACUTANEOUS MANIFESTATIONS

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OF URTICARIAL VASCULITIS

1. Arthralgias (50%) ? transient, migratory
2. GI (20%) ? abdominal pain, nausea, vomiting, diarrhea
3. Pulmonary obstructive disease (20%)

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4. Renal (5?10%) ? proteinuria, hematuria
5. Ocular (unusual) ? conjunctivitis, episcleritis, uveitis
6. Others - Raynaud's phenomenon, livedo reticularis, splenomegaly,
lymphadenopathy, idiopathic intracranial HTN, pericardial or

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muscle involvement

ASSOCIATED DISORDERS OF

URTICARIAL VASCULITIS

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? Systemic lupus erythematosus
? Sj?gren's syndrome
? Serum sickness
? Cryoglobulinemia

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? Infections ? hepatitis B or C virus, Epstein-Barr virus
? Rarely, solar or cold urticaria, drugs, hypergammaglobulinemia
CONTACT URTICARIA

? Development of urticaria at the site(s) of contact of urticant

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with skin or mucosa

? Percutaneous or mucosal penetration of the urticant may have

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distant effects, including acute urticaria or even anaphylaxis

? Immunologic and non-immunologic forms are recognized

CONTACT URTICARIA

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? Immunologic: sensitized to environmental allergens (grass, animals

and foods) or in glove-wearers (latex).

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? Non immunologic:

? Percutaneous microinjection of vasomediators

(histamine,acetylcholine, serotonin) via nettle stings

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? contact with histamine liberators that degranulate mast cells

(dimethylsulfoxide,cobalt chloride)
FOOD CONTACT

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HYPERSENSITIVITY SYNDROME

? Itching and mild swelling of the mouth, tongue

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and soft palate within minutes of eating fresh

fruits but not cooked fruit

? apples, pears, peaches and cherries,

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DIAGNOSIS

? Comprehensive history
? Duration of individual lesions, presence of purpura

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? Weals lasting more than 24?48 h, particularly if

painful or tender, suggest urticarial vasculitis

? Frequency of attacks, duration of disease, previous

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treatment, known triggers

? Past and family history,
? Occupation and leisure activities,

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DIAGNOSIS

? Assessment of the impact of the disease on the patient's

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quality of life.

? Asso. angiooedema (eg. Oropharynx result in difficulty in

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swallowing or breathing)

? Systemic symptoms
? Recent acute infection, drugs, nonprescription and

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prescription medicines, food
INVESTIGATIONS

? Rule out Infections
? Complete blood count

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? Stool for ova, cysts and parasites
? Thyroid autoab, Thyroid function tests
? C4 complement (angiooedema without weals)
? Nonorgan specific autoantibodies (eg ANA)
? Basophil histamine release assay / basophil activation tests

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? Helicobacter pylori (stool antigen or urea breath test)
? Chest Xray
? 25hydroxycholecalciferol (vitamin D)

TREATMENT

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? Detection and avoidance of the cause.
? First line therapies (H1 antihistamines)

minimal dosing which control episodes.

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H1 ? non sedating day time, sedating at night.

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A combination of an H1 antihistamine with
an H2 antagonist may be more effective than

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H1 antihistamines alone in some patients

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TREATMENT

Second line therapies (targeted therapy)
? Oral corticosteroids
? Leukotriene receptor antagonists

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? Doxepin,
? Danazol
? Sulphasalazine and dapsone

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