Which of the following are common allergic reactions?

Hives, rash, and skin eruptions are characteristic symptoms of common allergic reactions. Hives, also known as urticaria, present as raised, itchy welts on the skin and are a clear indication of the body's response to an allergen. Rashes can vary in appearance and may occur due to contact with irritants or allergens, reflecting a systemic immunological response. Skin eruptions, which could be in the form of vesicles or papules, also signify the inflammation and irritation caused by allergic reactions.

These symptoms arise because the immune system identifies a harmless substance as a threat, prompting an inflammatory response that manifests through these skin changes. Such reactions can be immediate or delayed, influenced by the type of allergen and the individual's immune system sensitivity.

In contrast, dry skin and redness can denote various skin conditions but are not specific to allergic responses. Swelling and discoloration could be signs of irritation or other dermatological issues, while peeling and flaking typically indicate dryness or skin barrier dysfunction rather than a direct allergic reaction. This context emphasizes why hives, rashes, and skin eruptions are emblematic of common allergic reactions.