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Skin Reaction
What happens when the UV Rays strike our body? To better understand the answer to this, we must keep in mind that the immediate response of our body to any threat is protection. The body tries to protect itself, whenever it is confronted by anything which can affect it. In case of UV Rays the body tries this with Melanin.
Melanin is deep brown coloured pigment and is found in the epidermis(the upper most layer of skin). Melanin is produced by
melanocytes which are scattered in the basal layer of epidermis.We derive our skin colour from Melanin. Melanin is scantily
present in white raced people (Europeans), moderately present in browns (Asians), and maximally present in dark colored people (Africans).
What does Melanin do?
Melanin acts as an endogenous screen against the harmful effects of UV radiation. It responds to the UV in two ways. The first response of melanin is immediate tanning, which occurs due to photo oxidation of pre existing melanin. The second response of the body is to produce more melanin delayed tanning. It occurs after about 48 hours and involves an increase in number of melanin granules. With both these responses the body screens itself against the UV Radiation.
Sensitive skin with low Melanin burns easily rather than tanning. See the table below.
| Type |
Sensitivity |
Reaction |
Examples |
| Sensitive Skin |
Always burns |
Never tans |
Red Haired, freckled |
| Sensitive Skin |
Always burns moderately |
Tans minimally |
Fair Skinned,Europeans |
| Sensitive Skin |
Burns |
Tans gradually |
Darker Caucasians |
| Normal Skin |
Burns minimally |
Always tans |
Mediterranean |
| Normal Skin |
Rarely burns |
Tans profusely |
Latin Americans, Indians |
| Normal Skin |
Never burns |
Deeply pigmented |
Negroids |
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