Red and Itchy Patch in Sindoor Area.

Hello Doctor, My mother (age ~50s) has recently developed a red, itchy patch right under the sindoor application line on her scalp. It started a few days ago after she applied a local sindoor (possibly containing harsh chemicals). Since then, the area has become slightly itchy and mildly irritated plus it became full whitish kind off There’s also a faint white patch developing under the sindoor area She has no other patches anywhere on the body. There’s no bleeding, oozing, pain, or rapid spreading — but she reports mild itching. I’ve now stopped the old sindoor and ordered a branded one and we’re keeping the area clean. I’m worried — could this be contact dermatitis, a fungal infection, or something more serious like vitiligo? Please advise on diagnosis and treatment. What cream or care should we follow for now?