Download MBBS (Bachelor of Medicine, Bachelor of Surgery) 1st Year, 2nd Year, 3rd Year and Final year Venereology and Leprosy 5 Urticaria and Angioedema PPT-Powerpoint Presentations and lecture notes
URTICARIA
&
ANGIOEDEMA
? Urticaria is characterized by transient skin or mucosal
swellings due to plasma leakage.
? Superficial dermal swellings are wheals
? Deep swellings of the skin or mucosa are angioedema
WHEALS
? Pruritic, pink/ red/pale
swellings of the superficial
dermis
? ? Initial flare
? Few millimeters to several
centimeters
? Number: few to numerous.
? Hallmark : individual lesions
come and go rapidly, by
definition, in general within 24
hours.
ANGIOEDEMA
? Swellings occur deeper in the
dermis/subcutaneous/submucosal
tissue.
? May affect the mouth rarely, the
bowel.
? Involved areas : normal or faint
pink in color, rather than red
? Painful rather than itchy,
? Larger and less well defined than
wheals
? Often last for 2 to 3 days
1. Classic immediate
hypersensitivity binding of
receptor-bound specific IgE by
allergen.
? Others: stimuli that act through
the IgE receptor
2. anti-IgE and
3. anti-FcRI antibodies
4. Non-immunologic stimuli:
opiates, C5a anaphylatoxin, stem
cell factor,some neuropeptides(e.g.
substance P)
? cause mast cell degranulation by
binding specific receptors,
independent of the FcRI
PATHOGENESIS
? The mast cell is the primary effector cell of urticaria.
? Degranulation:
1. Cross-linking of two or more adjacent FcRI on the mast cell
membrane
2. initiate a chain of calcium- and energy-dependent steps
3. fusion of storage granules with the cell membrane and
externalization of their contents.
PATHOGENESIS
? Basic pathology - capillary permeability, allowing proteins and
fluids to extravasate to the dermis.
1. Histamine and other proinflammatory mediators released on
degranulation ?
Bind receptors on postcapillary venules in the skin ?
Vasodilation and increased permeability to large plasma proteins
(albumin and immunoglobulins).
2. Histamine, TNF- and IL-8 upregulate adhesion molecules on
endothelial cells, promoting the migration of inflammatory cells
into the urticarial lesion.
CLINICAL CLASSIFICATION OF
URTICARIA AND ANGIOEDEMA
1. "Ordinary" (spontaneous) urticaria
2. Physical (inducible) urticarias
3. Urticarial vasculitis (vasculitis on skin biopsy)
4. Contact urticaria (induced by percutaneous or
mucosal penetration)
5. Angioedema without wheals
6. Distinctive urticarial syndromes
ACUTE vs CHRONIC URTICARIA
? All urticarias are acute initially
? "Chronic urticaria": usually defined as 6 weeks or more.
Applied to continuous urticaria occurring at least twice
a week off treatment for 6 weeks
? Urticaria occurring 6 weeks is called episodic / recurrent
ASSOCIATIONS OF CHRONIC URTICARIA
? Autoimmune thyroid disorders
? Vitiligo
? Insulin dependent diabetes
? Rheumatoid arthritis
? Pernicious anemia
? Helicobacter pylori gastritis
? Intestinal strongyloidiasis(endemic countries)
? ???Dental infections or gastrointestinal candidiasis
CLASSIFICATION OF PHYSICAL
URTICARIA
CLASSIFICATION OF PHYSICAL
URTICARIA
CLASSIFICATION OF PHYSICAL
URTICARIA
URTICARIAL VASCULITIS
1. Favors middle-aged women
2. Urticarial lesions >24 hours in duration;
painful & burning sensation as well as
pruritus;
3. Residual purpura as they resolve
4. Sites: often occur at pressure points
5. Concurrent angioedema :up to 40% of pts
6. Disease course: average of 3 years
EXTRACUTANEOUS MANIFESTATIONS
OF URTICARIAL VASCULITIS
1. Arthralgias (50%) ? transient, migratory
2. GI (20%) ? abdominal pain, nausea, vomiting, diarrhea
3. Pulmonary obstructive disease (20%)
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
muscle involvement
ASSOCIATED DISORDERS OF
URTICARIAL VASCULITIS
? Systemic lupus erythematosus
? Sj?gren's syndrome
? Serum sickness
? Cryoglobulinemia
? 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
with skin or mucosa
? Percutaneous or mucosal penetration of the urticant may have
distant effects, including acute urticaria or even anaphylaxis
? Immunologic and non-immunologic forms are recognized
CONTACT URTICARIA
? Immunologic: sensitized to environmental allergens (grass, animals
and foods) or in glove-wearers (latex).
? Non immunologic:
? Percutaneous microinjection of vasomediators
(histamine,acetylcholine, serotonin) via nettle stings
? contact with histamine liberators that degranulate mast cells
(dimethylsulfoxide,cobalt chloride)
FOOD CONTACT
HYPERSENSITIVITY SYNDROME
? Itching and mild swelling of the mouth, tongue
and soft palate within minutes of eating fresh
fruits but not cooked fruit
? apples, pears, peaches and cherries,
DIAGNOSIS
? Comprehensive history
? Duration of individual lesions, presence of purpura
? Weals lasting more than 24?48 h, particularly if
painful or tender, suggest urticarial vasculitis
? Frequency of attacks, duration of disease, previous
treatment, known triggers
? Past and family history,
? Occupation and leisure activities,
DIAGNOSIS
? Assessment of the impact of the disease on the patient's
quality of life.
? Asso. angiooedema (eg. Oropharynx result in difficulty in
swallowing or breathing)
? Systemic symptoms
? Recent acute infection, drugs, nonprescription and
prescription medicines, food
INVESTIGATIONS
? Rule out Infections
? Complete blood count
? 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
? Helicobacter pylori (stool antigen or urea breath test)
? Chest Xray
? 25hydroxycholecalciferol (vitamin D)
TREATMENT
? Detection and avoidance of the cause.
? First line therapies (H1 antihistamines)
minimal dosing which control episodes.
H1 ? non sedating day time, sedating at night.
A combination of an H1 antihistamine with
an H2 antagonist may be more effective than
H1 antihistamines alone in some patients
TREATMENT
Second line therapies (targeted therapy)
? Oral corticosteroids
? Leukotriene receptor antagonists
? Doxepin,
? Danazol
? Sulphasalazine and dapsone
THANK YOU
This post was last modified on 08 April 2022