When to worry about sun sensitivity with drug rash

A drug rash can become more noticeable after light exposure, with redness, itching, burning, or blistering on exposed skin. The timing of a new medicine, dose change, supplement, or topical product can help a clinician assess the reaction. A rash may also occur on covered skin, so do not assume that a sun-exposed pattern is the only clue.

Contact the prescribing clinician or pharmacist promptly and list every recent medicine, supplement, and skin product, including when each was started. Avoid further strong sun exposure and use protective clothing. Do not restart a suspected medicine, share medicines, or stop an essential treatment without advice unless emergency services instruct you to do so. Photograph changes.

Seek emergency help for facial or tongue swelling, trouble breathing, faintness, widespread blistering, skin pain, peeling, sores in the mouth or eyes, or fever with a rapidly worsening rash. Urgent review is also needed when the rash spreads quickly, becomes tender, or involves the eyes or genitals. These features can signal a serious reaction requiring immediate assessment.

Ask which medicine is most concerning, whether it should be paused or replaced, how long to avoid it, and what should be recorded as an allergy. Bring the medicine containers or an accurate list, including non-prescription products.