What is the best time to apply sunscreen, and can it be applied on the scalp?

Question

Hi doctor,

I am wondering when and how often to use sunscreen. One doctor said that you can burn anytime, so use discretion, while another said It is only necessary between the hours of 12 and 4 pm, when the sun is at its highest and most. I am also worried about using sunscreen with nice clothing, because I do not want to stain the clothing. Do I need it in the winter and do I also need to apply it to my scalp on occasions when I am outside without a hat? Please advise.

Answer 1

Hi,

Welcome to icliniq.com.

Thank you for your query,

Sunscreens are very important during day hours. It protects the skin from harmful effects of ultraviolet rays and, also it prevents wrinkling and aging of skin. Ultraviolet rays are the reason for early wrinkling of skin, it is called photoaging. Need of sunscreen varies depending on the skin type (Fitzpatrick's skin type). There are 6 skin types:

Skin type 1 and 2 - These skin types have very minimal melanin in their skin hence they are more prone for sun burn and eventually skin cancers called as basal cell carcinoma, squamous cell carcinoma, melanoma.
Skin type 3 and 4 - These skin types can burn a little on sun exposure but mostly tan.
Skin type 5 and 6 - This skin types will always tan, very minimal chances of sunburn on exposure to sunlight. Even they need sunscreen to protect their skin from tan and photoaging.
Skin type 3 and 6 - These skin types have relatively lower risk of skin cancer from ultraviolet rays compared to type 1 and 2.

Peak hours for maximum ultraviolet rays to reach earth is from 11 am to 4 pm. We will be exposed to maximum sunlight during this time, hence It is must to use sunscreen during this time. The key factor here is one should reapply the sunscreen every three to four hours if the exposure to sunlight is very prolonged, because the sunscreen loses its potency after four hours. Sunscreen should be used round the year irrespective of cloudy weather or rainy season because we are trying to protect our skin from ultraviolet rays and they are always there during day hours. Application on scalp is required for people who have sparse hair on the scalp, If the density of hair is thick, it is good enough to protect the skin of scalp. We usually see actinic keratosis, squamous cell carcinoma on scalp in people with sparse hair. There are many sunscreen that are transparent like clear gel. And most of the sunscreen once absorbed into the skin will not stain the clothing. There are certain sun protection clothing with ultraviolet protection factor 50+ are available. I recommend this kind of clothing for patients with known risk of skin cancer.

Please follow up for further assistances.

Thank you.

Answer 2

Hi,

Welcome back to icliniq.com.

Sunscreen has to be used before 11 am and 4 pm as I have mentioned we are trying to protect our skin from ultraviolet rays. Cumulative sun exposure does matter in a long run causing precancerous or cancerous skin growth - Skin type 1 and 2 are at risk of developing sunburn and skin cancer from sunlight, so it is recommended to use sunscreen even if it's for an hour. I understand it is lot of work to apply sunscreen everytime, but this is preventive measure that we can follow to avoid unwanted harmful effects of ultraviolet rays and it also has lot of benefits like prevents early wrinkling and prevents tan.

Please follow up for further assistances.

Thank you.