Hello. Thank you for writing to us at healthcaremagic Melasma presents as brownish pigmentation of the sun exposed skin on face, particularly malar areas and nose. The problem of recurrence is a common complaint in patients of melasma. The factors responsible being either inadequate sun protection or sub-optimal response to a pigment lightening agent. Adequate sun protection is an essential part of treatment of melasma or any facial hyperpigmentary skin condition. The combination of hydroquinone, tretinoin and mometasone that was initially prescribed to your wife is gold standard treatment for melasma and other facial hyperpigmentary conditions. However, it is only indicated for the initial treatment of melasma i.e for the first 1 or 2 months. This combination is not meant for long term/regular use because of the risk of side effects related to steroid component of this cream (mometasone furoate) like skin thinning, photosensitivity, acne and hirsutism in females. Therefore, once an effective response has been initiated with this combination, it should be sustained or maintained with other safer pigment lightening ingredients like kojic acid, hydroquinone, glycolic acid, Azaleic acid etc along with regular use of a broad spectrum sunscreen, throughout the day. However, if sun protection is adequate and still treatment is not able to completely clear pigmentation or there is a recurrence, the treatment can be changed or modified to a different skin lightening agent Or it can be combined with chemical peeling sessions e.g Glycolic acid peeling to produce additive results. Regards