Side effects of sunscreen and how to use it properly

To understand this, let’s first look at the two types of sunscreen. Chemical sunscreens absorb sunlight and work like a sponge. They contain chemicals such as oxybenzone, avobenzone, octocrylene and ecamsule. Incidentally, these are the chemicals that have been cited by the FDA for further investigation. 

Physical sunscreens work by deflecting the sun's rays. They contain titanium dioxide and zinc oxide. These are visible and look like white cream unlike chemical sunscreens that are rubbed in and can’t usually be seen. 

The chemicals mentioned above are under investigation to see if they can lead to cancer, birth defects and other adverse reactions. Note that the FDA has not branded them unsafe, and even the researchers who have carried out the study have not recommended against their use.

In fact, the evidence against oxybenzone (which is the most publicized substance) is based on studies in rats. Further, the rats directly injected the substance, and that too in large quantities. Experts have said that humans are not exposed to such large quantities of the chemical, so it is incorrect to draw conclusions based on this. Studies on the effects of oxybenzone in humans have so far shown no adverse effects.

However, another study suggested that daily application of oxybenzone in pregnant women could cause it to be absorbed into the foetus and cause developmental problems to the baby. So far, evidence of this has not been found in literature so the concern is still based on conjecture. 

Read more on Pregnancy here

Given all these recommendations, the FDA has suggested physical sunscreens as an alternative for those who are concerned. This means that sunscreens with titanium dioxide and zinc oxide have been deemed safe. 

There were also concerns that sunscreen actually causes cancer. But studies have countered these claims and said that it was increased sunlight exposure that led to skin cancer, and not the sunscreen itself. Perhaps those who applied sunscreen got a false sense of complete protection and lowered their guard.

The other side effects of sunscreen are to do with allergic skin reactions. These include: 

• Drying or tightening of the skin 
• Acne
• Burning and itching at the site of application 
• Pus in hair follicles
• Pain in the hairy parts of the body
• Swelling of the skin 
• Formation of blisters 
• Eye irritation

These side effects are rare but you should immediately inform your doctor and discontinue use of the product. 

Sunscreen is also not recommended for infants under the age of 6 months. For children older than 6 months of age, alcohol based sunscreen should not be used. Also do not use alcohol based sunscreen on inflamed skin since this can worsen the condition. Alcohol-based sunscreen should be used for oily skin, and creams and lotions are better for dry skin. 

Read more: Skin allergies

Discuss with your doctor about any drug interactions you may be concerned about as well. 

Apply sunscreen liberally to areas that are not covered by clothing. 

Use a sunscreen that has an SPF (sun protection factor) rating of at least 30, water resistant and broad spectrum. This means that it will protect against both UVA and UVB rays.

Apply sunscreen at least 30 minutes before leaving for the outdoors. 

Reapply sunscreen every two hours as it gets dissipated by sweat. This is very important and is often overlooked. Also reapply sunscreen if you have been swimming or swimming excessively.

Use enough sunscreen to fill a shot glass to cover your body and rub thoroughly into the skin. People often do not use enough sunscreen to protect themselves from the harmful rays of the sun. You should also use lip balm with SPF protection. These should be applied 40 minutes before going out. 

Read more: Home remedies for sunburn

Sunscreen alone is not enough and you should follow these other steps as well:

• Wear light, full sleeved clothes to cover more parts of your body. 
• Wear sunglasses and a hat to protect your eyes, head and face.
• Avoid the sun when it is at its brightest and seek shade when you are outdoors.