RESUMO
Infections of the hand can result in significant limitation of the function of the hand, and may even require partial amputation of a digit. A felon is an abscess of the distal pulp of the fingertip, which can spread rapidly through the flexor tendon sheath when not treated appropriately. Knowledge of the anatomy and the correct method of physical examination are essential when assessing a patient suspected of having a felon or flexor tendon sheath infection. Here we present two patients with a complicated felon resulting in palmar necrosis of the distal phalanx of the thumb, in which a groin flap was used to reconstruct the thumb. This article describes the relevant anatomy, physical examination and treatment of a felon and flexor tendon sheath infection to prevent a complicated course.