蕁麻疹VS 吳青穎

Clerk 雲智謙 . 洪睿

2010/01/28

蕁麻 (urtica)

蕁麻科 (Urticaceae)植物其葉子長著充滿毒液的刺毛，可保護自己免於給草食動物吞食。如人的皮膚碰到毒毛就很不幸了，皮膚馬上產生蜂蟄般的疼痛，還有浮腫的疹子，這種疹子即典型的蕁麻疹。

遠在公元前四世紀，蘇格拉底就已發現碰到蕁麻可以引起蕁麻疹。蕁麻疹的英文病名為 urticaria ， urtica就是蕁麻的拉丁文名，指的是碰到蕁麻後，皮膚疹子之似火燒灼般的疼痛感。

我國古人也很早就發現了蕁麻的多種特性，在明《本草綱目毒草類三十種》裡就提到了蕁麻：“蕁麻生汗寧府山野中，其莖有刺，高二三尺。葉似花桑上有毛芒可畏，觸人如蜂蟄。”

蕁麻疹

蕁麻疹是一種很常見的皮膚病，會使病人的皮膚出現極癢的膨疹，有如蚊子叮了一般的腫塊，雖可自行消退，但常反覆發生，來去有如風一般，故又俗稱「風疹」

另名 “風團”“風包”

outline

Introduction Definition Pathogenesis Classification (type, subtype …)

Introduction (1)

Urticaria, or hives, is a common disorder affecting up to 25 percent of the population

The usual urticarial lesion is an intensely pruritic, circumscribed, raised, erythematous plaque, often with central pallor.

Individual lesions may enlarge and coalesce with other lesions, and then typically will disappear over a few hours without leaving residual marks on the skin unless there is damage from scratching

Introduction (2)

The most common complaint of patients with urticaria is pruritus that may cause difficulties with sleep or work. Significant disability has been reported in the quality of life of patients with chronic urticaria

Urticaria is a process mediated by the cutaneous mast cell in the superficial dermis. By comparison, angioedema involves the deeper dermis and subcutaneous tissues. Angioedema may be disfiguring if it involves the face and lips, or life-threatening if airway obstruction occurs from laryngeal edema or tongue swelling.

Definition

Urticaria is characterized by the sudden appearance of wheals and/or angioedema Whereas 85 percent of children

experience urticaria in the absence of angioedema, 40 percent of adult patients with urticaria also experience angioedema.

Morphology may be variable (1)

Morphology may be variable (2)

Morphology may be variable (3)

angioedema

angioedema

Pathogenesis

Etiology and diagnosis of urticaria, UpToDate

Intravenous administration

classification

acute

EAACI/GA2LEN/EDF/WAO guideline: definition, classification and diagnosis of urticariaAllergy 2009: 64: 1417–1426

Classification of urticaria on the basis of its duration, frequency, and causes

Acute urticaria: More than two-thirds of cases of urticaria are self-

limited. defined as outbreaks of urticarial lesions that do not

extend in duration beyond six weeks. The lesions of acute urticaria are characterized by a

rapid onset and resolution within several hours and they can be recurrent

A presumptive trigger such as a drug, food ingestion, insect sting, or infection can occasionally be identified

Chronic urticaria: defined by the presence of hives, usually on most

days of the week, for a duration of longer than six weeks.

However, in 80 to 90 percent of adults and children with chronic urticaria, no external cause can be identified

About 40 percent of patients with chronic urticaria have associated angioedema, which typically affects the lips, cheeks, and periorbital areas of the face, extremities, and genitals

Epidemiology, healthcare, resources, use and clinical features of different types of urticaria.

Alergológica 2005

*Foods and additives Milk, egg, peanuts, nuts, soy, and wheat are the

most common agents to cause generalized urticaria in children.

In adults, fish, shellfish, tree nuts, and peanuts are most often implicated

*DERMOGRAPHISM means to ''write on the skin.'' rapid onset of a wheal and flare reaction after

firm stroking, scratching, or the application of pressure

most common of the physical urticarias

Clinical findings?

IgE and IgE receptor related? Atopic Diathesis

w/ family Hx of asthma, rhinitis, or eczema are presumed to be IgE dependent.

However, infrequently accompanies an exacerbation of asthma, rhinitis, or eczema.

Specific Antigen Sensitivity Food: shellfish, nuts, milk, eggs, and

chocolate Drug: penicillin

Physical Urticaria/Angioedema?

Dermographism （ skin writing） Pressure Urticaria Vibratory Angioedema Cold Urticaria Cholinergic Urticaria Local Heat Urticaria Solar Urticaria Exercise-Induced Anaphylaxis Adrenergic Urticaria

other

Contact Urticaria Papular Urticaria Urticaria/Angioedema

Mediated by Bradykinin, the Complement System, or Other Effector Mechanisms

Urticarial Vasculitis Serum Sickness Reactions to the

Administration of Blood Products

Infections Urticaria/Angioedema

after Direct Mast Cell Degranulation

Urticaria/Angioedema Related to Abnormalities of Arachidonic Acid Metabolism

Chronic Idiopathic Urticaria and Idiopathic Angioedema

Miscellaneous

Systemic d’s that may induce urticaria

Urticaria or urticarial-like lesions may occasionally be a presenting or early feature of a systemic disorder. With the exception of autoimmune thyroid disease, these disorders are rare. systemic s/s: fever, arthralgias, arthritis, weight

changes, bone pain, or lymphadenopathy painful urticarial, long-lasting (longer than 36 to 48

hours), or appear ecchymotic, as these are characteristics of vasculitic lesions

residual ecchymosis or hyperpigmentation upon resolution

Urticaria that are refractory to treatment

Systemic d’s that may induce urticaria

Autoimmune thyroid disease Systemic lupus erythematosus Cryoglobulinemia Urticarial vasculitis Mastocytosis Schnitzler's syndrome Familial cold autoinflammatory syndrome Muckle-Wells syndrome Malignancy