Surgical Treatment of Acute and Chronic Paronychia and Felons



Surgical Treatment of Acute and Chronic Paronychia and Felons


Jennifer Etcheson

Jeffrey Yao





ANATOMY



  • The nail complex consists of the nail bed, nail plate, and perionychium (FIG 2).


  • The nail plate sits below the proximal nail fold.


  • The perionychium is the border tissue which surrounds the nail.


  • The eponychium is the tissue that attaches closely to the nail plate proximally, commonly referred to as the cuticle.


  • The nail folds consist of skin, which continues underneath the visible edges to form a protective barrier.


  • The pulp of each digit consists of multiple compartments separated by fibrous septa.



    • These vertical septa extend from the periosteum of the distal phalanx to the epidermis, lending structural support to the fingertip.






FIG 1 • Felon in coronal and sagittal section.


PATHOGENESIS



  • Acute paronychia results from the introduction of bacteria into the space between the nail fold and the nail plate, either proximally or laterally.



    • This commonly occurs as a result of a hangnail, nail biting, artificial nails, or an overzealous manicure.


  • Chronic paronychia results from colonization and infection by organisms that enter the space between the nail plate and the cuticle, eponychium, and nail fold.



    • Infection may result from repeated exposure to moisture.


    • This chronic infection and inflammation lead to fibrosis of the eponychium, which, in turn, leads to decreased vascularity of the dorsal nail fold.


    • This decreased vascularity predisposes to repeated bacterial insults, resulting in the characteristic clinical exacerbations.


  • Felons often result from penetrating trauma or from bacterial inoculation through the exocrine sweat glands contained within the pulp.



    • Cellulitis and local inflammation lead to local ischemia, which, in the setting of the closed spaces defined by septa, leads to increased pressure.


    • Fat necrosis and abscess formation result from the increased pressure, which, in turn, causes a further increase in pressure and, in effect, a compartment syndrome.


NATURAL HISTORY



  • If acute paronychia is left untreated, an early infection will turn into an abscess along the nail fold.



    • The abscess may then extend into the pulp space or into the eponychium and then to the opposite side of the nail.


    • Purulence at the base of the nail may cause ischemia of the germinal matrix, which then may lead to temporary or permanent nail growth arrest.


  • Herpetic whitlow improves without any intervention in approximately 3 weeks.



    • Many cases of herpetic whitlow are misdiagnosed as acute paronychia or felon.







      FIG 2 • Anatomy of the nail complex.


    • Subsequent incision and drainage may lead to secondary bacterial infection.


  • Chronic paronychia are characterized by induration of the eponychium punctuated by episodes of swelling and drainage.


  • A felon, if left untreated, may lead to osteomyelitis or septic flexor tenosynovitis.


PATIENT HISTORY AND PHYSICAL FINDINGS



  • In acute paronychia, the patient will complain of swelling and pain immediately adjacent to the nail.



    • If an abscess has formed, there may be erythema and purulent drainage.


  • In chronic paronychia, the patient will present with a chronically indurated and rounded eponychium characterized by repeated episodes of inflammation and drainage.


  • Herpetic whitlow is characterized by pain and swelling followed by the appearance of multiple vesicular lesions.



    • The pain typically is out of proportion to the physical findings, and the fingertip is not tense (in contrast to a felon).


  • A patient with a felon will present with severe throbbing pain, swelling, and a tense fingertip pad.



    • A felon will not extend proximal to the distal interphalangeal (DIP) joint flexion crease unless it is associated with septic flexor tenosynovitis.


IMAGING AND OTHER DIAGNOSTIC STUDIES



  • Radiographs are indicated to rule out osteomyelitis or if a foreign body is suspected.


  • The diagnosis of herpetic whitlow is confirmed by Tzanck smear, which will show multinucleated giant cells.


  • Patients suspected of having a systemic illness should have the appropriate laboratory workup.

Jul 22, 2016 | Posted by in ORTHOPEDIC | Comments Off on Surgical Treatment of Acute and Chronic Paronychia and Felons
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