Which statement about allergic reactions is true?

When considering allergic reactions, it's important to focus on the distinctions between immediate and delayed responses. Immediate allergic reactions, such as anaphylaxis, can be severe and potentially life-threatening, whereas delayed reactions typically manifest over hours or days and may not always carry severe consequences. Therefore, the assertion that delayed signs are less serious than immediate ones can be misleading.

The second statement regarding skin reactions developing immediately indicating allergic tolerance is also inaccurate. Immediate reactions often suggest an active allergic response rather than tolerance.

Given these insights, the choice that states the first statement is false and the second statement is true accurately captures the essence of allergic responses. The correct answer reflects the understanding that while immediate reactions can be severe, delayed reactions do not consistently indicate mildness and tolerance. This reinforces the need for a careful assessment of allergic reactions rather than a blanket perspective that all reactions are mild and self-limiting.