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 is His Slave and Messenger.
We do not know what you read in the website which you referred to in the question. As we have already mentioned (in previous Fataawa), vitiligo is not necessarily a punishment; rather, it may just be a test from Allaah by which He raises the degrees and expiates the sins of a person who accepts it with patience.
For more benefit on the excellence of patience during affliction, please refer to Fatwa 83577. Also, for more benefit, please refer to Fatwa 118920.
Vitiligo - white patches on parts of the skin that are different from the original color of the skin – is not a contagious disease, and it is generally not repulsive, as is the case for leprosy. Al-Maawardi said: “As regards vitiligo, it is a change in the color of the skin, but it does not affect the blood that is under the skin, and it is not permanent, and it is not repulsive, so the spouse is not given the choice to annul the marriage contract because of it.”
One should seek to be cured from it through prayer, Ruqyah, and consultation of specialists. For more benefit, please refer to Fatwa 82432.
It should be noted that in the Sunnah, it is a command to stay away from the people affected by contagious diseases, such as leprosy and plague, for example, and to believe that these diseases do not infect by themselves, but by Allaah’s Decree. Abu Hurayrah narrated that the Prophet said: “There is no contagion…but run away from the leprous as you run from the lion.” [Al-Bukhari] Ibn Hajar said in Fat-h Al-Baari when clarifying the correct meaning of this Hadeeth: “…what is meant by negating contagion is that something does not infect by itself contrary to what people in the Pre-Islamic era used to believe: that the diseases infect by themselves without the Will or Decree of Allaah. So the Prophet, sallallaahu ‘alayhi wa sallam, invalidated this belief and ate with a leper in order to show people that it is Allaah Who causes illnesses and cures them. However, [the Prophet] prohibited them from getting close to a leper to teach them that this is a cause that Allaah has made to normally have such an effect. So in his prohibition there is confirmation of the existence of those cause, and in his action [eating with a leper] there is an indication that those means are not independent; rather, if Allaah wants to take away their effect, then they will not have any effect, and if He wills, He can maintain their effect, so they have an effect...”
Based on this, it is not problematic that in the Sharee’ah, it is commanded to avoid people who have contagious diseases, and this does not involve discrimination. Rather, it has to do with utilizing the means and repelling harm from oneself. In an authentic Hadeeth, ‘Ubaadah, may Allah be pleased with him, narrated that the Prophet, sallallaahu ‘alayhi wa sallam, said: “There should be no harm nor reciprocal harm.” [Ahmad]
Allaah Knows best.