Classification of Urticaria:
Classification on basis
of duration of symptoms:
Acute Urticaria:
Symptoms last for less than 6 weeks.
Chronic Urticaria:
Symptoms last for more than 6 weeks.
Classification based on underlying cause:
Idiopathic:
In 50 % of cases,urticarial is idiopathic or has no
underlying cause.
This is most common form of urticarial.
Intermittent fleeting wheels occur at any skin site with or
without angioedema.
Lesions maybe annular,popular or even serpiginous.
The lesions may last from minutes to hours and may recur
over less than 6 weeks.
Trigger factors for urticarial include:
Infections
Food
Medications
Contact allergic
Cholinergic
Urticaria:
This occurs after a warm shoer/bath or after exercise.
Patients are usually 10 – 30 years old.
Lesions consist of pinhead sized wheals with a red flare
around them
Solar Urticaria:
This occurs rarely in clinical practice.
In this condition,sunlight causes an acute urticarial eruption.
Symptoms occur within 30 minutes of sunlight exposure.
Lesions resolve quickly on cessation of sunlight exposure.
Differential Diagnosis of Solar urticaria are:
Porphyria : Lesions resolve with scarring
Polymorphic light eruption: Lesions take days to weeks to
resolve.
Pressure Urticaria:
These lesions occur at site of pressure on the skin.
It usually presents in pressure areas.
The rash appears after 6 hours of contact.
Symptoms are usually recurrent.
It usually responds to Dapsone or Montelukast.
Urticarial Rash
Urticarial Hives