Urticaria, commonly referred to as hives, appears as raised, well-circumscribed areas of erythema and edema involving the dermis and epidermis that are very pruritic. It may be acute (< 6 weeks) or chronic (>6 weeks). Urticaria may be confused with a variety of other dermatologic diseases that are similar in appearance and are also pruritic; usually, however, it can be distinguished from these diseases by an experienced clinician.
Chronic hives usually aren’t life-threatening. But the condition can be very uncomfortable and interfere with sleep and daily activities.
Classification of urticaria
Urticaria is classified according to its duration.
Chronic urticaria may be spontaneous or inducible. Both types may co-exist.
Inducible or physical urticaria includes: