Sunscreen- The Double Edged Sword

Sunscreens have long being recognized as substances to provide effective protection against the detrimental effects of solar radiation. The deleterious effects of sun exposure can be either acute (e.g. sunburn and drug-induced photo toxicity) or chronic (potential long-term risks of repeated sun exposures like solar elastosis, keratoses, induction of skin cancers, and alteration of immune responses and functions)[1]. Due to growing incidences of skin cancer, dermatologists are regularly recommending sunscreens to their patients. Action spectra of normal and abnormal reactions of solar radiationare variable, which can serve as a deciding factor in prescribing the appropriate sunscreens catering to individual patient needs. Increased recognition of the harmful effects of ultraviolet (UV) radiation on the skin has triggered development of two main types of sunscreens namely Physical and Chemical, based on the nature of UV filter present in them. The physical also known as Inorganic sunscreen protects our skin by deflecting or blocking the sun's rays and usually contains Titanium dioxide (TiO2) and Zinc oxide (ZnO) as active ingredients. They are generally stable with lesser chances of degradation. TiO2 having a pitiable UVA protection with an excellent UVB defence may lead to skin eruptions in predisposed individuals. While Zinc oxide with a superior defence against the entire spectrum of UVB and UVA rays is generally well tolerated and can be used even on delicate skin. Both are FDA approved but cosmetically physical sunscreens are less tempting as being thick and opaque and they leave a white cast.