This would need a proper clinical examination to come to a definite diagnosis. But this could be cold sores
usually appear on
your lips. Occasionally, they occur on
your nostrils, chin or fingers. Fever, menstruation, stress and exposure to the sun may trigger a recurrence. Cold sores generally clear up without treatment in seven to 10 days.
If you experience frequent bouts, your doctor may prescribe an antiviral medication to treat cold sores.