Acute urticaria resolves in 4–6 weeks. It is usually associated with drugs (penicillin, sulfonamides,
aspirin); food allergens (e.g., chocolate, shellfish, eggs, cheese, nuts, peanut butter, berries, tomatoes,
strawberries); new pets; or infections (upper respiratory infection, especially streptococcal in
children). Pregnancy may aggravate it into pruritic and urticarial papules and plaques of pregnancy
(PUPPP syndrome).
Chronic urticaria is instead longer than 6 weeks and may last for years. One half of patients are free of
symptoms at 12 months, but 20% have lesions that persist for decades. In 80% of cases, the etiology
remains unknown, with possibilities including the same causes of acute urticaria, as well as cryoglobulins, autoimmune diseases, food additives, inhalants, viruses (hepatitis B), parasites, arthropods (scabies and fleas), neoplasms, and even stress (often responding to hypnosis). Still, physical factors are the
most commonly identifiable etiologies of chronic urticaria, being responsible for one out of five cases.Among them are cold, water, sun, pressure, vibration,and even stroking (demographism), often coexistingin the individual patient. Physical urticarias are easily recognized by challenged test.
aspirin); food allergens (e.g., chocolate, shellfish, eggs, cheese, nuts, peanut butter, berries, tomatoes,
strawberries); new pets; or infections (upper respiratory infection, especially streptococcal in
children). Pregnancy may aggravate it into pruritic and urticarial papules and plaques of pregnancy
(PUPPP syndrome).
Chronic urticaria is instead longer than 6 weeks and may last for years. One half of patients are free of
symptoms at 12 months, but 20% have lesions that persist for decades. In 80% of cases, the etiology
remains unknown, with possibilities including the same causes of acute urticaria, as well as cryoglobulins, autoimmune diseases, food additives, inhalants, viruses (hepatitis B), parasites, arthropods (scabies and fleas), neoplasms, and even stress (often responding to hypnosis). Still, physical factors are the
most commonly identifiable etiologies of chronic urticaria, being responsible for one out of five cases.Among them are cold, water, sun, pressure, vibration,and even stroking (demographism), often coexistingin the individual patient. Physical urticarias are easily recognized by challenged test.