Photo Explainer:

Vitiligo Vulgaris vs MBEH-treated skin.

After his death Benoquin cream was found in MJ’s home. Its active ingredient is MBEH and it is used to depigment skin. Technically you can call it bleaching. The treated areas have a confetti-like pattern. Vitiligo-affected skin is lighter and more uniform.

The pattern we see on this photo is consistent with that. Notably there are body parts without darker patches. We can conclude that these areas are not being treated. They are: face, hands, wrists, elbows, upper chest, neck.

These happen to be body parts where vitiligo vulgaris typically occurs, and this is a common distribution pattern. We can therefore reasonably assume that MJ had vitiligo vulgaris on these areas and used MBEH to even out the skin color on his arms and chest.