What
is the reaction after sunburn?
The symptoms of sunburn are different by UVB and UVA. They are pigmentation and erythema.
UVB : Erythema and PPD (persistent pigment
darkening)
UVA: immediate pigment darkening
Pigmentation
1.
Caused by melanin
2.
After 24-48 suntanned, the
melanocyte will start to produce melanin and move into keratocytes.
3.
Melanin in keratocyte could
protect the cell nucleus to damage by the UV radiation.
4.
The skin color is inherent, not
by the distribution of melanocytes. The different skin color is influenced by
the amount of melanin, types and size.
5.
Aside UVR, chronic inflammation
and heat will also cause pigmentation.
The pigmentation can be divided into two
types.
Immediate pigment darkening
By UVA
The color is because of the melanin oxygen
from the existed keratocyte in epidermis. The oxygen is from blood circulation
in subcutaneous tissue. So the reaction will reach the maximum after 1-2 hrs sunburned.
Then it will disappear after 3-24 hrs.
Persistent pigment darkening
By UVB
It is the new melanin from keratocyte
syntheses. It will appear after 2-24 hrs.
MPPDD: minimal persistent pigment darkening
dose
PPD: persistent pigment darkening
MPPD: minimal persistent pigment darkening
(10J/cm2)
30 mins suntanned in the afternoon in summer
Erythema
By UVB
1.
Many reasons will cause
erythema such as heat, insect bites, allergy, sun light (UV radiation), and so
on.
2.
If the skin is exposure to the
high doses of sun light (UV radiation), the erythema is the consequence of cell
protection for the damaged skin.
3.
The appearance is red due to
the blood vessel dilatation for increasing the nutrition for the cellular restoration.
Some abbreviations
MED: minimal erythema dose of 24hrs
exposure under sun.
MED of Skin type I is around 210 W/m2
SED: (standard erythema dose) The minimal
erythema dose of experiment measurement.
SED = 100J/ m2
--------------------------------------------------------------------------------
help to find the specific skincare product ingredients by "skin+" App
Outdoor tables such as patio dining units may help add luxurious to the spaces the place there are put. These are fashionable patio units and are identified for their texture. Patio tables, Picnic tables, conservatory 1xbet patio units, and lots of|and plenty of} others at the moment are|are actually} out there here with super-saving deals just for you. You should purchase these superb patio furniture dining units at beautiful prices.
ReplyDelete