What to expect from topical corticosteroids for sun allergy

Polymorphic light eruption, often called sun allergy, can produce itchy red bumps, patches or small blisters after ultraviolet exposure. A corticosteroid cream or ointment reduces local inflammation, so discomfort and visible irritation may ease during the prescribed course. It treats the flare rather than changing your sensitivity to sunlight.

The medicine may feel different from a moisturiser, and the formulation matters on different body areas. A clinician may choose a preparation suited to the rash and its location. Improvement does not mean the skin is ready for unrestricted sun exposure.

Apply a thin layer only to the affected skin, following the label or your clinician’s directions. Wash your hands before and after application unless your hands are being treated. Keep the product away from the eyes, lips and broken skin unless specifically instructed.

Reduce ultraviolet exposure with shade, protective clothing and broad-spectrum sunscreen that your skin tolerates. Do not apply extra product to compensate for a missed application, and do not share someone else’s steroid. A bland moisturiser can support the skin barrier when used as directed.

Contact a clinician if the rash is spreading, becoming painful, oozing or failing to improve as expected. Seek urgent help for facial swelling, trouble breathing, faintness or a rapidly worsening blistering reaction. A new sun-related rash may have another cause, especially when it persists away from sun-exposed areas.

Ask which strength and formulation you have, where it can be applied, and how long the course should last. Also ask what sun protection is appropriate for your skin and what to do if the eruption returns.