It seems strange, then, that allergic reactions to corticosteroids actually occur—especially since these medications are used to treat allergic reactions. While severe allergic reactions to corticosteroids are extremely rare, they do in fact occur. Most allergic reactions to corticosteroids are less severe, however, and result from the topical formulations—occurring in up to 6% of people. Allergic reactions to oral or injected formulations are rarer, occurring in less than 1% of people. Causes of allergic reactions to corticosteroids may be due to IgE antibodies , or as a result of delayed-type hypersensitivity reactions caused by T-cells (a type of white blood cell).
Nebulisers are machines that turn the liquid form of your short-acting bronchodilator medicines into a fine mist, like an aerosol. You breathe this in with a face mask or a mouthpiece. Nebulisers are no more effective than normal inhalers. However, they are extremely useful in people who are very tired (fatigued) with their breathing, or people who are very breathless. Nebulisers are used mainly in hospital for severe attacks of COPD when large doses of inhaled medicines are needed. They are used less commonly than in the past, as modern spacer devices are usually just as good as nebulisers for giving large doses of inhaled medicines. You do not need any co-ordination to use a nebuliser - you just breathe in and out, and you will breathe the medicine in.