Praise be to Allah

Firstly:

Any physical characteristic in a woman or in a man that may ordinarily be off-putting to a spouse and have an impact on physical pleasure, and detract from love and compassion between husband and wife, is regarded as a defect.

This has been explained previously in the answers to questions no. 75405 and 111980. 

Whatever is deemed to be a defect must be disclosed at the time of the marriage contract, and should not be concealed, so that there will be no deceit and lack of sincerity.

Ibn al-Qayyim (may Allah have mercy on him) said: If the Prophet (blessings and peace of Allah be upon him) forbade vendors to conceal defects in their products, and he forbade the one who was aware of the defect to conceal it from the purchaser, then how about defects with regard to marriage? The Prophet (blessings and peace of Allah be upon him) said to Faatimah ibn Qays, when she consulted him about marrying Mu‘aawiyah or Abu Jahm: “As for Mu‘aawiyah, he is poor and has no wealth; as for Abu Jahm, his stick his stick never leaves his shoulder (i.e., he travels a great deal).” Thus it is known that disclosing faults in the case of marriage is more appropriate and more obligatory.

End quote from Zaad al-Ma‘aad (5/168-169)

Secondly:

The scholars have stated that leprosy is a defect that must be disclosed and the other party must be given the option of annulling the marriage, if it has been concealed from him or her.

As for vitiligo, it is something other than leprosy.

Al-Maawardi (may Allah have mercy on him) said:

Leprosy is the appearance of whiteness on the skin in which the blood of the skin and the flesh beneath it disappears, and it is contagious and may be passed to one’s offspring and people with whom one mixes. People fear it and are put off by it, so it is not possible to have complete physical enjoyment in this case …

But in the case of vitiligo, it is a change in the colour of the skin, but it does not take away the blood and is not off-putting to people, so in this case there is no option (of annulling the marriage).

End quote from al-Haawi al-Kabeer (9/342)

Al-‘Adawi said in his Haashiyah (5/257), after confirming that there is the option (of annulling the marriage) in the case of leprosy: There is no option (of annulling the marriage) in the case of vitiligo. End quote.

An-Nawawi stated in Rawdat at-Taalibeen (7/176) that vitiligo does not come under the same rulings as leprosy.

However the situation of people nowadays varies. In many societies vitiligo is regarded as a defect, and a man is usually put off by a woman who is affected by this condition; if a marriage goes ahead without the husband being aware of it, then after he finds out about it he feels that he has been cheated and deceived, in that case he may hurt his wife or shame her because of that, and he become obsessed with the issue and start to fear that this small spot may spread and affect the rest of the body, or that the disease may be transferred to the children. Undoubtedly this has a negative effect on love and compassion that are the purpose of marriage, and replaces them with aversion and prevents full physical enjoyment between them.

Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) was asked:

Is a mild case of vitiligo regarded as one of the defects that affect marriage? In other words, if a man finds vitiligo in his wife, is it regarded as a defect?

He replied:

Yes, it is undoubtedly a defect, because people are usually put off by it and he may not be able to feel comfortable with his wife except if Allah wills. It is a defect whether it appears in the man or the woman; even if a man has vitiligo and a woman marries him and is unaware of it, it is a defect and she has the option of annulling the marriage because of it.

But in terms of sin, the man is sinning and the woman is sinning if they have this defect, or any other defect that would prevent complete physical enjoyment, and does not disclose it to the other. Undoubtedly concealing it is haraam and comes under the heading of deceit, and the Prophet (blessings and peace of Allah be upon him) disavowed those who practice deceit.

End quote from Liqa’ al-Baab al-Maftooh (39/10)

The most correct view with regard to this issue:

Is that reference should be made concerning it to what is customary and usual in each society, because societies vary in the way they regard this disease. Some of them regard it as a defect and off-putting, and others do not view it in this manner.

We put this question to our shaykh, ‘Abd ar-Rahmaan al-Barraak (may Allah preserve him) and he said:

If the vitiligo is regarded as a defect according to social custom, then it must be disclosed and it is prohibited to conceal it. But if customarily it is not regarded as a defect, then it does not have to be disclosed. End quote.