For which condition are antihistamines typically indicated?

Antihistamines are primarily indicated for allergic rhinitis because they work by blocking the action of histamine, a substance in the body that contributes to allergy symptoms. Allergic rhinitis, commonly known as hay fever, is characterized by symptoms such as sneezing, runny or itchy nose, and itchy eyes, all of which occur as a result of exposure to allergens like pollen, dust mites, or pet dander. By inhibiting histamine, antihistamines reduce these symptoms, making them an effective treatment for individuals experiencing allergic reactions associated with rhinitis.

In contrast to allergic rhinitis, severe acne is typically treated with topical or systemic medications that target acne lesions and inflammation, while metal allergies are managed through avoidance of the triggering metal rather than the use of antihistamines. Chronic migraine headaches may require a different class of medications, such as triptans or preventive treatments, since antihistamines aren't specifically used to address migraine headaches. Thus, antihistamines are clearly indicated for managing the symptoms of allergic rhinitis rather than for the other conditions listed.