How to differentiate epidermodysplasia verruciformis from flat warts

The main differences between epidermodysplasia verruciformis and flat warts are as follows: 1. Etiology: Both conditions are associated with human papillomavirus (HPV) infection. However, patients with epidermodysplasia verruciformis have a genetic susceptibility to the virus and often have a history of consanguineous marriage, whereas flat warts are mostly caused by HPV infection without specific genetic predisposition. 2. Symptoms: Epidermodysplasia verruciformis is characterized by generalized, eruptive flat wart-like papules. The skin lesions vary in size from rice grain to soybean, are round or polygonal in shape, hard in texture, diverse in color, and gradually increase in number with symmetrical distribution. Flat warts are mostly flat, round or oval papules, similar in color to surrounding skin, commonly found on exposed areas such as the face and back of hands, and relatively fewer in number. 3. Disease Course and Outcome: Epidermodysplasia verruciformis progresses very slowly and persists for years without spontaneous regression; in some patients, skin lesions may develop into squamous cell carcinoma. Flat warts are self-limiting, with some cases resolving spontaneously without scarring.