A patient with melasma is advised on photoprotection beyond conventional sunscreen. Pigmentation in her lesions is aggravated even by indoor visible light exposure. Which component should her sunscreen contain to address this?

• A Titanium dioxide micronised to nanoparticle size only
• B Higher concentration of avobenzone
• C Octinoxate combined with oxybenzone
• D Iron oxide pigments providing broad-spectrum visible light protection ✓

Explanation

Visible light, particularly in the blue-violet range, induces sustained pigmentation and free radical generation in melasma-prone skin, and conventional UV filters offer no protection against it. Opaque, tinted sunscreens containing iron oxides block visible light and are recommended for melasma. Avobenzone, octinoxate, and oxybenzone filter only ultraviolet wavelengths, and micronised titanium dioxide alone does not provide opaque visible light shielding, so these distractors fail.

Reference: Fitzpatrick's Dermatology, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.