what is the harm in steaming face every day?
Heat can exacerbate melasma, steaming your face may cause it to get worse. Avoid sun exposure and be diligent with your sunscreen!
If anything, heat could make your melasma darker, but certainly will not help it. A cosmetic dermatologist can examine you and can offer topical medication and treatments depending on your skin type. Sun avoidance is most important.
