eMedicine Specialties > Emergency Medicine > Infectious Diseases

Paronychia

Heather Murphy-Lavoie, MD, FAAEM, Assistant Professor, Section of Emergency Medicine and Hyperbaric Medicine, Louisiana State University School of Medicine, New Orleans; Clinical Instructor, Department of Surgery, Tulane University School of Medicine
Micelle J Haydel, MD, Associate Clinical Professor of Medicine, Residency Director, Section of Emergency Medicine, Louisiana State University Health Science Center

Updated: Oct 8, 2008

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

• Acute paronychia is most commonly caused by Staphylococcus aureus or Streptococcus species.
• A mixed bacterial infection is common, particularly in patients with diabetes.¹⁵
• If recurrent or chronic, the infection has an increased likelihood of being mycotic, primarily Candida albicans.¹⁶

Differential Diagnoses

Other Problems to Be Considered

Bowen disease
Kaposi sarcoma
Malignant melanoma
Squamous cell carcinoma
Pemphigus vulgaris¹⁷
Pyogenic granuloma
Reiter disease
Splinters, foreign body
Mucous cyst
Subungual fibroma
Glomus tumor
Blastomycosis
Squamous cell carcinoma

Workup

Laboratory Studies

• Laboratory studies are not routinely necessary for this paronychia process.
• A Gram stain and wound culture may be performed, although they are not routinely necessary to identify the exact bacterial cause since incision and drainage is usually sufficient to clear the infection.
• Obtain a slide preparation using potassium hydroxide (KOH) and fungal culture if candidal infection is suspected.
• Tzanck smear or viral culture may be helpful when herpetic whitlow is suspected.
• Skin biopsy may be indicated in chronic cases where malignancy is suspected.

Imaging Studies

• Imaging studies are not routinely necessary with this infection.
• Obtain a plain film radiograph of the fingertip if osteomyelitis is suspected because of recurrent infection, elevated erythrocyte sedimentation rate (ESR), or presence of risk factors for osteomyelitis.
• Consider a radiograph if the patient has a history of recent finger trauma.
• Obtain a radiograph if foreign body is suspected.

Procedures

See incision and drainage section of Emergency Department Care.

Treatment

Prehospital Care

The patient with a paronychia is typically ambulatory. Splinting the finger with clean gauze is necessary to decrease discomfort until definitive treatment is rendered.

Emergency Department Care

• The treatment of choice for a paronychia is incision and drainage.¹⁸
• Provide warm compresses or soaks with half-strength hydrogen peroxide.
• Elevate the infected nail.
• Keep fingers clean and dry.
• Incision and drainage
  • Incision and drainage are not indicated for herpetic whitlow (the most common infection mistaken for paronychia), mucous cyst, glomus tumor, and osteomyelitis.
  • For maximum patient comfort, the digit is anesthetized with an appropriate digital nerve block.
  • The nail plate and surrounding skin are cleaned with an appropriate antiseptic agent. Blunt dissection with the tip of a sharp instrument or point of a surgical blade is used to elevate the lateral nail fold. The operator attempts to enter the sulcus between the lateral nail plate and lateral epithelium. Purulent drainage can erupt when the sulcus is entered by the instrument tip. The lateral fold of skin should be elevated slightly and irrigated with isotonic sodium chloride solution using a catheter tip syringe.
  • A "run-around" describes a severe paronychia that extends along the medial and lateral nail edges. In such cases, or when a large paronychia is present, the cavity should be splinted open with a small wick to prevent adhesion and reformation.
  • If purulence has tracked under the nail, excision of the ipsilateral nail may be necessary.
  • The presence of a subungual abscess (ie, "floating nail") requires nail plate removal. The degree of debridement is commensurate with the degree of nail bed infection.
  • The presence of a finger pulp abscess or felon may require an additional incision of the pad of the finger tip to adequately drain. Be careful to avoid the neurovascular bundles that run on the lateral edges of the finger.

Consultations

It is necessary to consult a hand surgeon if cellulitis, deep space infection, glomus tumor, mucous cyst, or osteomyelitis is suspected.

Medication

Antibiotics are not necessary if the incision successfully achieves adequate drainage and no cellulitis is present. Most paronychia infections can be managed without antibiotics. Over-the-counter analgesics are usually sufficient. If cellulitis is present, antibiotics are indicated. Penicillin is probably the first-line agent, covering oral flora well. In consideration of allergies and contraindications, an oral cephalosporin agent may be considered for outpatient treatment. Clindamycin may be considered to cover methicillin-resistant Staphylococcus aureus and anaerobic organisms. Combination therapy with an IV agent that provides antimicrobial activity against staphylococci is used for inpatient therapy. See Hand Infections for a detailed discussion of antibiotics.

Chronic paronychial infections are usually managed with oral antifungals such as ketoconazole, itraconazole, or fluconazole.¹⁶ This is beyond the scope of emergency medicine practice since many of these agents require a prolonged course with monitoring of laboratory tests to avoid complications.

Antibiotics

Therapy must cover all likely pathogens in the context of the clinical setting.

Clindamycin (Cleocin)

Semisynthetic antibiotic produced by 7(S)-chloro-substitution of 7(R)-hydroxyl group of parent compound lincomycin. Inhibits bacterial growth, possibly by blocking dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest. Widely distributes in the body without penetration of CNS. Protein bound and excreted by the liver and kidneys.

Dosing

Adult

300 mg PO qid

Pediatric

10-25 mg/kg/d PO divided qid for 10 d

Interactions

Increases duration of neuromuscular blockade induced by tubocurarine and pancuronium; erythromycin may antagonize effects of clindamycin; antidiarrheals may delay absorption of clindamycin

Contraindications

Documented hypersensitivity; regional enteritis, ulcerative colitis, hepatic impairment, antibiotic-associated colitis

Precautions

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Adjust dose in severe hepatic dysfunction; no adjustment necessary in renal insufficiency; associated with severe and possibly fatal colitis by allowing overgrowth of Clostridium difficile

Penicillin VK (Beepen-VK, Betapen-VK, Pen.Vee K, Robicillin VK, V-Cillin K, Veetids)

Inhibits the biosynthesis of cell wall mucopeptide. Bactericidal against sensitive organisms when adequate concentrations are reached, and most effective during the stage of active multiplication. Inadequate concentrations may produce only bacteriostatic effects.

Dosing

Adult

500 mg PO tid/qid for 10d

Pediatric

<12 years: 25-50 mg/kg/d PO divided tid/qid up to 3 g/d
>12 years: Administer as in adults

Interactions

Probenecid may increase effectiveness by decreasing clearance; tetracyclines are bacteriostatic, causing a decrease in the effectiveness of penicillins when administered concurrently

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Caution in renal impairment

Cephalexin (Keflex)

First-generation cephalosporin arrests bacterial growth by inhibiting bacterial cell wall synthesis. Bactericidal activity against rapidly growing organisms. Primary activity against skin flora. Used for skin infections or prophylaxis in minor procedures.

Dosing

Adult

500 mg PO qid for 7-10 d

Pediatric

25-50 mg/kg PO divided qid; not to exceed 4 g/d

Interactions

Coadministration with aminoglycosides increases nephrotoxic potential

Contraindications

Documented hypersensitivity

Precautions

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Adjust dose in renal impairment

Follow-up

Further Inpatient Care

• Admission for paronychia is rarely required unless associated with a significant cellulitis, tendonitis, or deep space infection of the hand requiring IV antibiotics.

Further Outpatient Care

• Warm water soaks are the mainstay of treatment. Early in the course of this disease, prior to the development of an abscess, frequent soaking may be sufficient to resolve the infection.
• Instruct patients to leave any wick in place for 24-48 hours, depending on the depth and extent of the purulent space.
• After removing the wick, patients can begin warm soaks 3-4 times per day and should have a follow-up examination in 48 hours after incision and drainage to assure the infection is resolving appropriately.

Deterrence/Prevention

• Trim hangnails to a semilunar smooth edge with a clean sharp nail plate trimmer. Trim toenails flush with the toe tip. Do not bite the nail plate or lateral nail folds.
• Avoid prolonged hand exposure to moisture. If hand washing must be frequent, use antibacterial soap, thoroughly dry hands with a clean towel, and apply an antibacterial moisturizer.
• Wear rubber or latex-free gloves.
• Control diabetes mellitus.

Complications

• Paronychial infections may spread to the pulp space of the finger, developing a felon.
• If neglected, infection may continue to spread to involve the tendons or deep spaces of the hand.
• Secondary ridging, thickening, and discoloration of the nail may be observed.
• Nail loss may occur.

Prognosis

• The prognosis is usually good if treated promptly.
• The incidence of chronic paronychia is increased among immunocompromised individuals.

Patient Education

• For excellent patient education resources, visit eMedicine's Skin, Hair, and Nails Center and Psoriasis Center. Also, see eMedicine's patient education articles Paronychia (Nail Infection) and Nail Psoriasis.

Miscellaneous

Medicolegal Pitfalls

• Failure to incise and drain adequately
• Failure to have patient return for rechecks until infection is clearly resolving
• Failure to place a wick to hold open abscess cavity during first 24 h
• Failure to remove lateral nail if a subungual infection is present
• Failure to diagnose herpetic whitlow, trauma such as incision may worsen the course of this disease process
• Unnecessary treatment with antibiotics

Special Concerns

• Paronychia has been known to initiate from malignant lesions. Any history of prior malignancy or a pigmented irregular appearance of surrounding tissue should result in appropriate suspicion and referral for biopsy.
• Painless swelling lateral to the nail plate in a patient with osteoarthritis should prompt investigation for mucous cyst.
• Constant severe pain with nail plate elevation, bluish discoloration of the nail plate, and blurring of the lunula suggest the presence of a glomus tumor.

Multimedia

Media file 1: Paronychia incision and drainage.

Media file 2: Paronychial erythema and edema with associated pustule. This suggests a bacterial etiology.

Media file 3: Paronychia, side view.

Media file 4: After simple drainage, there is purulent return.

References

1. Brook I. Aerobic and anaerobic microbiology of paronychia. Ann Emerg Med. Sep 1990;19(9):994-6. [Medline].

2. Chronic paronychia: what you should know. Am Fam Physician. Feb 1 2008;77(3):347-8. [Medline].

3. Rockwell PG. Acute and chronic paronychia. Am Fam Physician. Mar 15 2001;63(6):1113-6. [Medline].

4. Canales FL, Newmeyer WL 3rd, Kilgore ES Jr. The treatment of felons and paronychias. Hand Clin. Nov 1989;5(4):515-23. [Medline].

5. Dahdah MJ, Scher RK. Nail diseases related to nail cosmetics. Dermatol Clin. Apr 2006;24(2):233-9, vii. [Medline].

6. Colson AE, Sax PE, Keller MJ, et al. Paronychia in association with indinavir treatment. Clin Infect Dis. Jan 2001;32(1):140-3. [Medline].

7. 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].

8. 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].

9. Tosti A, Piraccini BM, D'Antuono A, et al. Paronychia associated with antiretroviral therapy. Br J Dermatol. Jun 1999;140(6):1165-8. [Medline].

10. 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].

11. Daniel CR 3rd. Paronychia. Dermatol Clin. Jul 1985;3(3):461-4. [Medline].

12. Jules KT, Bonar PL. Nail infections. Clin Podiatr Med Surg. Apr 1989;6(2):403-16. [Medline].

13. 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].

14. Turkmen A, Warner RM, Page RE. Digital pressure test for paronychia. Br J Plast Surg. Jan 2004;57(1):93-4. [Medline].

15. 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].

16. 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].

17. Engineer L, Norton LA, Ahmed AR. Nail involvement in pemphigus vulgaris. J Am Acad Dermatol. Sep 2000;43(3):529-35. [Medline].

18. Jebson PJ. Infections of the fingertip. Paronychias and felons. Hand Clin. Nov 1998;14(4):547-55, viii. [Medline].

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

Contributor Information and Disclosures

Author

Heather Murphy-Lavoie, MD, FAAEM, Assistant Professor, Section of Emergency Medicine and Hyperbaric Medicine, Louisiana State University School of Medicine, New Orleans; Clinical Instructor, Department of Surgery, Tulane University School of Medicine
Heather Murphy-Lavoie, MD, FAAEM is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, American Medical Association, Society for Academic Emergency Medicine, and Undersea and Hyperbaric Medical Society
Disclosure: Nothing to disclose.

Coauthor(s)

Micelle J Haydel, MD, Associate Clinical Professor of Medicine, Residency Director, Section of Emergency Medicine, Louisiana State University Health Science Center
Micelle J Haydel, MD is a member of the following medical societies: Alpha Omega Alpha, American College of Emergency Physicians, American Medical Association, Sigma Theta Tau International, Society for Academic Emergency Medicine, and Southern Medical Association
Disclosure: Nothing to disclose.

Medical Editor

Jerome FX Naradzay, MD, FACEP, Medical Director, Consulting Staff, Department of Emergency Medicine, Maria Parham Hospital; Medical Examiner, Vance County, North Carolina
Jerome FX Naradzay, MD, FACEP is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Jeter (Jay) Pritchard Taylor III, MD, Compliance Officer, Attending Physician, Emergency Medicine Residency, Department of Emergency Medicine, Palmetto Health Richland, University of South Carolina; Medical Director, Department of Emergency Medicine, Palmetto Health Baptist
Jeter (Jay) Pritchard Taylor III, MD is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, American Medical Association, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

CME Editor

John D Halamka, MD, MS, Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center
John D Halamka, MD, MS is a member of the following medical societies: American College of Emergency Physicians, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Chief Editor

Pamela L Dyne, MD, Professor of Clinical Medicine/Emergency Medicine, David Geffen School of Medicine at UCLA; Attending Physician, Department of Emergency Medicine, Olive View-UCLA Medical Center
Pamela L Dyne, MD is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

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