Detailed answer

Melasma and vitiligo vulgaris are both skin conditions that can cause patches of depigmentation on the skin. However, there are some differences between the two that can help differentiate them. Melasma is characterized by symmetric brown patches usually on the face, which is often triggered by hormonal changes or sun exposure. On the other hand, vitiligo vulgaris results in white patches that can appear anywhere on the body, and it is an autoimmune condition where the body's immune system attacks its own pigment cells. While the appearance can be similar, a thorough examination by a dermatologist along with a detailed medical history can help in accurately diagnosing and differentiating melasma from vitiligo vulgaris.