If you suddenly experience redness, itching, or burning after sun exposure in your 40s or 50s, it might not be just a sunburn. It could be a sun allergy , also known as photosensitivity . As we age, our skin becomes more reactive due to immune changes, medications, and hormonal shifts, making sun allergy more common in midlife. This post provides a detailed overview of the causes and symptoms of sun allergy, plus practical tips on how to protect and care for your skin as you age.     Main Causes of Sun Allergy Immune system changes: Aging affects how our immune system responds to UV light, increasing overreaction risks. Medications: Common drugs like antibiotics, painkillers, and blood pressure meds may trigger UV reactions. Hormonal changes: Decreased estrogen during menopause can weaken the skin barrier and increase sensitivity. Skincare ingredients: Retinol, essential oils, and certain fragrances can cause phototoxic reactions when expos...