| Various
types of classifications exist, the following classification
adopts a more practical approach.
1. Acute Urticaria and Urticaria with an Identifiable
Cause
In acute urticaria, a self evident precipitating
factor is usually present (table 1). Some patients with chronic
urticaria may also have a well defined cause although this
is uncommon.
2. Chronic Idiopathic Urticaria
Chronic idiopathic urticaria has long been
a demoralizing disease, baffling allergists and dermatologists
alike, to the detriment of the patient. Recent findings, however,
have shed light on causation in many, though not all, of these
patients.
The purpose of this review is to bring the
reader up to date on the current position regarding aetiology
and pathogenesis and the strength of the evidence. The review
also seeks to point up rational approaches to diagnosis and
treatment in the light of these developments.
3. Physical Urticaria - in this most striking
is dermographism. A useful procedure in confirming the diagnosis
of dermographism is challenge test with a caliberated dermographometer,
which measures the pressure being applied to the skin.
cholinergic urticaria
symptomatic dermographism
delayed pressure urticaria
solar urticaria
cold urticaria
aquagenic urticaria
vibratory urticaria
4. Angio-Oedema
Angioedema and urticaria involve the same
pathological process and can occur together:
* Urticaria is well-defined areas of temporary,
pruritic oedema of the dermis - well-circumscribed wheals
with raised erythematous borders and central blanching.
* Angio-oedema is non pitting, sub dermal oedema mainly visible
around easily distensible structures - peri orbital, lips,
tongue, oropharynx and genitals.
It can develop into pharyngeal obstruction
rapidly. Generally there is no itching of the affected skin
unlike urticaria.
5. Others: hereditary urticaria, contact
urticaria, papular urticaria, urticarial vasculitis, and urticaria
pigmentosa.
What
is Urticaria ?|Classification
of Urticaria|Chronic
Idiopathic Urticaria|Cholinergic
Urticaria|
Cold
Urticaria| Urticaria
causes|Traditional
Chinese Medicine and Urticaria|Pressure
Urticaria|
Solar
urticaria |
