Been on antihistamines for a week due to allergic reaction to methyprednisone severe burning and itching. symptoms have decreased in half. how long to stay on antihistamines?

Allergic reactions to corticosteroids are quite rare. They are more prevalent in people who have had repeated doses over time. Because you may be dealing with some longacting substances involved in allergic reactions,& as long as you're tolerating them, I recommend your taking antihistamines for a prolonged enough period where allergic signs & symptoms have been absent for at least a week or more