Hi Pimples do not occur due to allergy to food. Pimples occur due to blockage of oil from oil glands in the skin and it occurs under hormonal influence. Certain factors which may aggravate pimples are stress, oil based occlusive cosmetics and food items like milk and other dairy products. Pimples usually leave behind spots and chances of dark spots increase if you fiddle with them. Tanning occurs due to UV A rays in sunlight while SPF is a measure of protection from sunburn. Apply sunscreen 30 mins before stepping out and also it is equally important to reapply sunscreen every 3-4 hours if you spend more time outdoors. Consult a dermatologist for treatment of pimples and marks. You may undergo peeling sessions for removal of tan. Hope this helps. Best regards Dr Vijay Adhe, Eternis Skin & Hair Clinic, Pune. www.eternisclinic.com