All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship ]except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
There is no religious impediment to having these lumps on your forehead checked, and this is not against the religion, nor is it haraam; rather, it is considered seeking medical treatment, which is permitted by Allaah, The Exalted. There is no religious impediment either to undergo surgery to have these lumps removed, and it does not fall under the category of the prohibited changing of the creation of Allaah.
We have previously underlined the permissibility of undergoing cosmetic surgeries for the purpose of removing deformities in many fataawa. This also applies to the discoloration of your skin. If it amounts to deformation, then there is no religious impediment to using these products that remove the discoloration. Please refer to fatwa 86463 about the religious ruling on cosmetic surgery and the difference between those done to remove a deformity and those done for beautification purposes and to change the creation of Allaah and increase beauty.
We would like to highlight that there is no harm in using these products if they are temporary and removable, like those resembling henna and the other known cosmetics, the use of which has been declared lawful by scholars provided that they are ritually pure and are not harmful to one's health.
Allaah knows best.