What do steroids do for allergies

When I had my last Anaphalactic Shock three weeks ago, I was kept in hospital for a couple of days and when I left I was handed a prescription for steroids by the nurse, so did not get the chance to ask the consultant about them. I know they are prescribed for allergies, but I do not know what they actually do. Can anyone tell me?

[Dr Santos]

Hi,
Steroid drugs have long been used to treat moderate or severe allergic reactions. There is usually a marked and immediate symptomatic improvement.  Steroids work by decreasing the inflammation caused by allergic reactions. Topical steroid formulations are available for the treatment of allergic conditions of the nose, lungs and skin while oral steroids are given for the management of severe allergic reactions. I hope this helps. Take care and best regards.