What causes a bald spot under chin?

A bald spot under the chin can be caused by several factors, including alopecia areata, an autoimmune condition that leads to hair loss in patches. Other potential causes include fungal infections, skin conditions like psoriasis or eczema, and hormonal changes. Additionally, stress or trauma to the area can also contribute to localized hair loss. It's best to consult a healthcare professional for an accurate diagnosis and treatment options.