Detailed answer

Using a face mask when you have a cold sore can worsen the condition and delay the healing process. The pressure and friction caused by the mask can irritate the cold sore and potentially spread the infection to other areas of the face. Additionally, the moisture and warmth trapped by the mask can create an ideal environment for the virus to multiply. It is advisable to refrain from using a face mask until the cold sore has completely healed to prevent further complications or spreading the infection.