What should you know about topical antihistamines?

Topical antihistamines work where they are applied. Depending on the formulation, that may mean drops for itchy eyes, a nasal product for symptoms inside the nose, or a skin preparation for a local reaction. They reduce the effects of histamine, the chemical involved in itching, sneezing, watery eyes, and some swelling.

A product made for the skin should not be put in the eyes or nose, and eye or nasal products should not be used on broken skin unless the label or a clinician says so. Allergic rhinitis may cause a blocked or runny nose, while allergic conjunctivitis commonly causes itchy, watery eyes. House dust mites and pets are examples of possible triggers.

Read the label for the intended body area, age limits, frequency, storage, and advice about contact lenses. Wash your hands, avoid touching an applicator tip to the eye or skin, and use the smallest amount needed according to instructions. Stop and seek advice if burning, swelling, rash, or worsening symptoms follow use.

Reduce exposure to a known trigger where practical, such as keeping pets out of a sleeping area or reducing dust accumulation. If symptoms affect several areas, a clinician or pharmacist can help choose between a topical product and a medicine that works throughout the body.

Get urgent help for swelling of the lips, tongue, or throat, trouble breathing, faintness, or rapidly worsening widespread symptoms. Arrange an assessment for persistent eye pain, light sensitivity, vision change, thick discharge, or nasal symptoms with severe facial pain or fever.

Ask which formulation fits your symptoms, whether it is safe with contact lenses or other medicines, how long to try it, and what to use if the trigger cannot be avoided. Mention pregnancy, breastfeeding, glaucoma, or other eye conditions before using eye products.