Filiform warts and flat warts are different. They have commonalities in that both are benign growths caused by human papillomavirus (HPV) infection of the skin and mucous membranes. However, they differ in their virus subtypes and shapes. Filiform warts are a type of common wart, characterized by their elongated, thin protrusions with keratinized tips, hence named filiform warts. These often occur in areas such as the neck, forehead, and eyelids. Flat warts are caused by HPV type 3 infections, typically occurring on the face, backs of hands, and forearms. The typical lesions are rice grain- or soybean-sized flat elevated papules with smooth surfaces, either the color of normal skin or light brown. They are numerous and densely packed. Scratching them can lead to a string of bead-like arrangements along the direction of the scratch.