Introduction
Background
A paronychia is a superficial infection of epithelium lateral to the nail plate. The acute painful purulent infection is most frequently caused by staphylococci but commonly has mixed aerobic and anaerobic flora.1 The patient's condition and discomfort are markedly improved by a simple drainage procedure. Chronic paronychial infections also occur, but these are usually fungal rather than bacterial in nature. This discussion focuses on acute paronychial infections.
Paronychial erythema and edema with associated pustule. This suggests a bacterial etiology.
Paronychia, side view.
Pathophysiology
A paronychial infection usually starts in the lateral nail fold. Cracks, fissures, or trauma to the nail fold allows bacterial entry through the skin barrier.2 Patients at risk include those with dyshidrotic eczema, contact dermatitis, and those with chronic dry, chaffed, or irritated skin such as dishwashers, florists, gardeners or housekeepers. Occasionally, the infection includes the complete margin of skin around the nail plate. It results from mechanical separation of the nail plate from the perionychium. Early in the course of this disease process (<24 h), cellulitis alone may be present. An abscess can form if the infection does not resolve quickly.
Frequency
United States
Paronychia is the most common infection of the hand representing 35% of all hand infections in the United States.3
Mortality/Morbidity
Failure to properly treat a paronychia can result in hand infection and, occasionally, systemic infection from hematogenous extension.
- The abscess initially forms on the lateral nail fold. It can spread to the eponychium, eventually forming a "horseshoe" that includes the opposite nail fold.
- It may spread to the pulp space of the finger, creating a felon.
- An untreated infection can spread to the deep spaces of the hand and beyond.4
Sex
Paronychia is more common in females than in males, with a female-to-male ratio of 3:1.
Age
No predilection exists.
Clinical
History
The patient is usually otherwise healthy but complains of acute onset of pain and swelling around the nail.
- Patients may give a history of nail biting, finger sucking, trivial finger trauma, finger exposure to chemical irritants, acrylic nails or nail glue, sculpted nails, or frequent hand immersion in water.2,5
- Query patients about the duration of symptoms, history of nail infections and previous treatment, and exposure to chemicals or water. Several medications are thought to affect the nail matrix, resulting in an increase in associated infections.6,7
- It is important to identify risk factors for a more complicated course such as diabetes mellitus,8 immunocompromise, history of steroids, and retroviral use. Indinavir and lamivudine, in particular, are thought to be associated with an increased incidence of paronychia formation.6,9 Painless swelling or severe swelling that radiates requires an expanded differential diagnosis.10
- Pain and swelling surrounding the nail are the most common complaints.
- Chronic and recurrent paronychial infections should be scrutinized to rule out malignancy or fungal infection.11,12,13
Physical
- Erythema
- Edema
- Tenderness along the lateral nail fold
- Fluctuance
- The digital pressure test can be used to detect the presence of an abscess. Pressure is applied to the palmar surface of the distal finger, and, if an abscess is present, the area of the abscess will blanch with palmar pressure.14
- Infection may be isolated to the lateral nail fold; however, the finger and hand should be examined closely to rule out any extension of the infection such as a runaround abscess, abscess extending under the nail plate, felon, or tendonitis.
- Examine closely for any tissue irregularity that may be a clue to malignancy.
- Look for signs of herpetic whitlow infection such as vesicles on an erythematous base.
- Green coloration of the nail may suggest Pseudomonas species infection.
- Hypertrophy of the nail plate may be a clue to fungal infection.
Causes
More on Paronychia |
 Overview: Paronychia |
| Differential Diagnoses & Workup: Paronychia |
| Treatment & Medication: Paronychia |
| Follow-up: Paronychia |
| Multimedia: Paronychia |
| References |
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References
Brook I. Aerobic and anaerobic microbiology of paronychia. Ann Emerg Med. Sep 1990;19(9):994-6. [Medline].
Chronic paronychia: what you should know. Am Fam Physician. Feb 1 2008;77(3):347-8. [Medline].
Rockwell PG. Acute and chronic paronychia. Am Fam Physician. Mar 15 2001;63(6):1113-6. [Medline].
Canales FL, Newmeyer WL 3rd, Kilgore ES Jr. The treatment of felons and paronychias. Hand Clin. Nov 1989;5(4):515-23. [Medline].
Dahdah MJ, Scher RK. Nail diseases related to nail cosmetics. Dermatol Clin. Apr 2006;24(2):233-9, vii. [Medline].
Colson AE, Sax PE, Keller MJ, et al. Paronychia in association with indinavir treatment. Clin Infect Dis. Jan 2001;32(1):140-3. [Medline].
Hijjawi JB, Dennison DG. Acute felon as a complication of systemic Paclitaxel therapy: case report and review of the literature. Hand. Sep 2007;2(3):101-3. [Medline].
Kapellen TM, Galler A, Kiess W. Higher frequency of paronychia (nail bed infections) in pediatric and adolescent patients with type 1 diabetes mellitus than in non-diabetic peers. J Pediatr Endocrinol Metab. Jun 2003;16(5):751-8. [Medline].
Tosti A, Piraccini BM, D'Antuono A, et al. Paronychia associated with antiretroviral therapy. Br J Dermatol. Jun 1999;140(6):1165-8. [Medline].
Yip KM, Lam SL, Shee BW, et al. Subungual squamous cell carcinoma: report of 2 cases. J Formos Med Assoc. Aug 2000;99(8):646-9. [Medline].
Daniel CR 3rd. Paronychia. Dermatol Clin. Jul 1985;3(3):461-4. [Medline].
Jules KT, Bonar PL. Nail infections. Clin Podiatr Med Surg. Apr 1989;6(2):403-16. [Medline].
Muñiz AE, Evans T. Chronic paronychia, osteomyelitis, and paravertebral abscess in a child with blastomycosis. J Emerg Med. Oct 2000;19(3):245-8. [Medline].
Turkmen A, Warner RM, Page RE. Digital pressure test for paronychia. Br J Plast Surg. Jan 2004;57(1):93-4. [Medline].
Riesbeck K. Paronychia due to Prevotella bivia that resulted in amputation: fast and correct bacteriological diagnosis is crucial. J Clin Microbiol. Oct 2003;41(10):4901-3. [Medline].
Daniel CR 3rd, Daniel MP, Daniel J, et al. Managing simple chronic paronychia and onycholysis with ciclopirox 0.77% and an irritant-avoidance regimen. Cutis. Jan 2004;73(1):81-5. [Medline].
Engineer L, Norton LA, Ahmed AR. Nail involvement in pemphigus vulgaris. J Am Acad Dermatol. Sep 2000;43(3):529-35. [Medline].
Jebson PJ. Infections of the fingertip. Paronychias and felons. Hand Clin. Nov 1998;14(4):547-55, viii. [Medline].
Further Reading
Keywords
paronychia, finger infection, paronychial infection, onychia lateralis, onychia periungualis, inflammation of the nail fold, incision and drainage, I and D, I&D, paronychia, nail infection, superficial infection of the epithelium, staphylococci, infection of the hand, eponychia, felon, runaround abscess, herpetic whitlow, chronic paronychia, acute paronychia
