I-metabolism ye-pigment yesikhumba engavamile - i-chloasma

I-Chloasma yisifo esivamile esitholakala esikhumbeni se-pigmentation emisebenzini yomtholampilo. Iyenzeka kakhulu kwabesifazane abaneminyaka yobudala yokuzala, futhi ingabonakala nasemadodeni angaziwa kakhulu. Ibonakala ngemibala elinganayo ezihlathini, ebunzini nasezihlathini, ikakhulukazi ekumeni kwamaphiko ovemvane. Ophuzi ngokukhanyayo noma onsundu ngokukhanyayo, onsundu onzima onzima noma omnyama okhanyayo.

Cishe zonke izinhlanga nezinhlanga ezincane zingase zibe nalesi sifo, kodwa izindawo ezinokuchayeka kakhulu kwe-UV, njengeLatin America, Asia, ne-Afrika, zinezigameko eziphezulu. Iningi leziguli liqala ukugula lineminyaka engu-30 no-40 ubudala, kanti izigameko kwabaneminyaka engu-40 no-50 ubudala zingu-14% no-16% ngokulandelana. Abantu abanebala elikhanyayo baqala ukusheshe baqale, abanebala elimnyama bakhule kamuva, ngisho nangemva kokunqamuka kokuya esikhathini. Ucwaningo oluvela kubantu abancane eLatin America lukhombisa izehlakalo ezisukela ku-4% kuye ku-10%, u-50% kwabesifazane abakhulelwe kanye no-10% kwabesilisa.

Ngokwendawo yokusabalalisa, i-melasma ingahlukaniswa ngezinhlobo ezi-3 zemitholampilo, okuhlanganisa ubuso obuphakathi (okubandakanya ibunzi, ikhala, izihlathi, njll.), i-zygomatic kanye ne-mandible, futhi izinga lezehlakalo lingu-65%, 20 %, kanye no-15%, ngokulandelana. Ngaphezu kwalokho, ezinye izifo zesikhumba ze-idiopathic, njenge-idiopathic periorbital skin pigmentation, kucatshangwa ukuthi zihlotshaniswa ne-melasma. Ngokwendawo yokubeka i-melanin esikhumbeni, i-melasma ingahlukaniswa ngezinhlobo ze-epidermal, dermal kanye nengxube, phakathi kwazo uhlobo lwe-epidermal oluvame kakhulu, futhi uhlobo oluxubile yilona okungenzeka kakhulu.Isibani sikaWoodkuyasiza ekuhlonzeni izinhlobo zemitholampilo. Phakathi kwazo, uhlobo lwe-epidermal lunsundu ngokukhanyayo ngaphansi kokukhanya kwe-Wood; uhlobo lwe-dermal luyimpunga ekhanyayo noma eluhlaza okwesibhakabhaka ngaphansi kweso lenyama, futhi umehluko awubonakali ngaphansi kokukhanya kwe-Wood. Ukuhlukaniswa okunembile kwe-melasma kunenzuzo ekukhetheni ukwelashwa kamuva.