Acute urticaria: Hives lasting less than six weeks.

The cause of this type of hives is usually more difficult to identify than those causing acute urticaria.

Though the fresh leaves can cause painful stings and acute urticaria, these are rarely seriously harmful.

Most cases of hives lasting less than six weeks (acute urticaria) are the result of an allergic trigger.

Acute viral infection is another common cause of acute urticaria (viral exanthem).

The causes can be similar to those of acute urticaria but can also include autoimmunity, chronic infections, hormonal disorders, and malignancy.

For acute urticaria, some topical creams, such as hydrocortisone, fluocinonide, or desonide, can also be prescribed to relieve itching.

Viral infections, such as glandular fever and herpes, dental and sinus infections, fungal infections, blood transfusions and vaccines can also cause acute urticaria.

Acute urticaria induced by the use of trichazole only reacted to treatment by taking a very hot bath in water containing epsom salts and other vitamins and minerals known to induce exfoliation.