Precautions for Summer.
Sunscreens: be sun “SMART” this summer
S: seek shade
M: maintain proper sun protective clothing, sunglasses, umbrella, hat
A: apply sunscreens, recommended 8 tablespoons daily
R: reapply after every 2 hrs
T: take frequent breaks from prolonged exposures
The sun is the best source of naturally occurring vitamin D; however, overexposure can lead to some disturbing sun damages. Before blaming the sun for the harmful outcomes, let's first understand the spectrum of light that it emits.
UVA light is further divided into two, UVA I (340nm to 400nm), and UVA II (320nm to 340nm). UVA I is weak and less potent than UVA II and UVB to cause erythema and melanoma.
Exposure to sunlight rich in UVA and UVB between 10 am and 4 pm can lead to photosensitivity, photoaging, and photodermatoses as they can penetrate into the deeper layers of the skin. Upon unprotected exposure to the sun, erythema occurs within 20 to 30 minutes as a result of oxidation of bleached melanin and dilation of dermal venules. This eventually begins to fade after 2 to 8 hours. However, pain and edema worsen after 14 to 20 hours and lasts 24 to 72 hours due to the dilation of the arterioles.
It is ideal to apply 1oz of sunscreen per average adult, preferably 20 to 30 minutes (2 hours for para-aminobenzoic acid PABA and PABA esters) before exposure to the sun. Reapply the sunscreen after every 2 hours particularly, after swimming, heavy exercise, perspiration, and toweling dry. Consider wearing a Sun Protection Factor (SPF) 30 or above to minimalize frequent reapplications.
Types: Sunscreens can be either chemical or physical-based upon the ingredients. Chemical sunscreens (PABA, PABA esters, Cinnamates, Salicylates, Benzophenones, Avobenzone, Phenylbenzimidazole sulfonic acid, and Ecamsule) absorb UVR. Only benzophenones such as benzophenone6, oxybenzone, dioxybenzone, and mexenone absorb both UVA and UVB. On the other hand, physical sunscreens (titanium dioxide and zinc oxide) reflect UVA and UVB.
1. If sensitive to sulphonamides, procaine, benzocaine, or thiazides, avoid PABA and PABA esters.
2. Discontinue use if irritation or rash occurs.
3. Avoid contact with eyes.
4. Do not use in infants younger than 6 months.
5. Use broad protection water-resistant sunscreens with SPF 30 and above, which protects against UVA and UVB.
6. Use shades, hats, sunglasses, and proper clothing when going outdoors.
7. Apply a combination product of low dose diethyltoluamide (DEET) suitable for 2 hourly application, ensuring maximum sun protection.
8. Regular sunscreen usage reduces the incidence of melanoma, carcinoma, and actinic keratoses.
9. Ensure to use sunscreens while on photosensitizing drugs, immunosuppressants, or with photodermatoses or hyperpigmentation disorders such as vitiligo and albinism.
Pharmacist Avanthi Reddy