AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• References

Hand infections can vary from routine problems (treated with oral antibiotics, immobilization, and limited incision and drainage)¹ to catastrophic surgical emergencies (resulting in significant compromise of hand function). The purpose of this article is to provide a systematic approach to the diagnosis, evaluation, and treatment of hand infections.

For excellent patient education resources, visit eMedicine's Skin, Hair, and Nails Center and Wounds Center. Also, see eMedicine's patient education articles Hand Injuries and Finger Infection.

Problem

Hand infections include superficial infections, infections of the nail, infections of the tendon and tendon sheath, infections of the deep spaces of the hand, septic arthritis, and osteomyelitis. (See also the eMedicine articles Hand Infections [in the Plastic Surgery section]; Hand Infections and Osteomyelitis [in the Emergency Medicine section]; and Septic Arthritis,Pediatrics [in the Orthopedic Surgery section].)

Etiology

Hand infections usually result from an injury, most commonly a laceration or an animal bite.^{2, 3} Most patients recall an inciting event that resulted in the inoculation of bacteria into the hand. Infections of the nail and of the nail folds can result from a nail deformity. (See also the eMedicine articles Nail Pathology [in the Orthopedic Surgery section] and Nailbed Injuries and Paronychia [in the Emergency Medicine section].)

Clinical

A thorough history of a hand infection includes determination of the onset, duration, any recent trauma, and any systemic symptoms (eg, fever, chills, diaphoresis).⁴ Most patients present with a 2- to 3-day history of cellulitis swelling, and occasionally, drainage. (See also the eMedicine articles Cellulitis [in the Emergency Medicine section] and Cellulitis [in the Infectious Diseases section].) 

Review of the patient's past medical history is important, because individuals with diabetes or an immunocompromised status require more aggressive treatment and closer observation.^{1, 4} Obtaining the patient's immunization history is also important. If the patient's tetanus status is unknown or out of date, administer tetanus prophylaxis.

The physical examination should include a thorough examination of the hand, with particular attention to cellulitis, lymphangitis, areas of fluctuance, range of motion, foreign bodies, and the presence or absence of Kanavel signs. (The 4 Kanavel signs are used to differentiate between infectious tenosynovitis and a superficial or localized abscess. In the presence of infectious tenosynovitis, the signs include intense pain, flexion posture, uniform swelling, and percussion tenderness. [See Relevant Anatomy.])

INDICATIONS

Section 3 of 10  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• References

Some early infections can be managed with antibiotics. For example, antibiotic treatment is appropriate for cellulitis, and oral antibiotics are usually the appropriate first line of treatment. However, persistent cellulitis or infections in immunocompromised patients should be treated with intravenous (IV) antibiotics until the cellulitis resolves. Then, completion of a course of oral antibiotics is appropriate. (See also the eMedicine articles Antibiotics: A Review of ED Use [in the Emergency Medicine section] and The Role of Antibiotics in Cutaneous Surgery [in the Dermatology section].)

If any signs of fluctuance or purulent wound drainage are present, incision and drainage is necessary. Furthermore, cellulitic infections that are unresponsive to antibiotics may require surgical exploration. Surgeons who undertake incision and drainage should be familiar with the anatomy of the hand, including the anatomy of the nail, the course of the digital neurovascular bundles, and the deep spaces of the palm. Furthermore, appropriate management requires close postoperative monitoring.

RELEVANT ANATOMY

Section 4 of 10  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• References

A brief review of the most common hand infections by anatomic location follows.

Acute paronychia involves the soft tissue around the fingernail and usually results from the inoculation of bacteria (most commonly Staphylococcus aureus) into the paronychia tissue from nail trauma or nail manipulation. Drain superficial abscesses with limited incision and drainage. Obtain cultures if possible. If the infection resulted from an ingrown nail, excision of the radial or ulnar one fourth to one half should be performed at the time of incision and drainage. Infections that involve the eponychial fold can be drained by elevating the eponychium, either sharply or with a freer or elevator. The patient should receive a course of oral antibiotics with good staphylococcal coverage (eg, IV cefazolin or oral cephalexin). In addition, the patient should soak the finger in antiseptic solution 2-3 times a day. (See also the eMedicine articles Paronychia [in the Emergency Medicine section] and Paronychia [in the Dermatology section].)

Chronic paronychia usually is caused by Candida albicans and occurs most commonly from chronic immersion in water (as in dishwashers), previous trauma, or nail defects. Treatment with topical antifungal agents and behavior modification is occasionally successful. Excision of a portion of the nail or removal of the entire nail may be necessary.

A felon is a subcutaneous abscess over the distal pulp of a digit or thumb. Felons usually result from a penetrating injury. The pulp contains multiple compartments separated by fibrous septa that make infections in this area complex. Surgical drainage is necessary when an area of palpable fluctuance is present. Use of several incisions has been described for drainage. However, the preferred incision is radial or ulnar longitudinal. Incisions directly over the finger pad or tip are avoided. Also, subcutaneous septa should be broken up to drain all areas of infection, and the wound is left open. After drainage, warm antiseptic soaks and oral antibiotics are administered. The antibiotic is based on the nature of the infection. Parenteral antibiotics should be considered in patients with diabetes or in those who are immunocompromised. Persistent chronic paronychial infections may also require intravenous antibiotics. (See also the eMedicine article Felon.)

Deep-space infections in the hands are possible; the 2 deep spaces in the palm are the midpalmar space and the thenar space. Infections in these areas usually result from injuries such as bites or puncture wounds. These infections may cause cellulitis, fluctuance, and/or pain. In addition, the second, third, and fourth web spaces are potential sites for infection. Web-space infections can spread from the palmar subfascial space in a dorsal direction, forming what is commonly referred to as a "collar button abscess." On examination, patients typically have pain, swelling, and fluctuance on the palmar or dorsal web-space surface. 

Flexor tenosynovitis is a potentially devastating infection that can result in significant scarring of the flexor tendon sheath with resultant compromise in hand function. These infections usually are caused by a penetrating injury (eg, bite, puncture wound). In the early 1900s, Kanavel described a tetrad of physical findings in patients with flexor tenosynovitis: (1) flexed position of the digit, (2) fusiform swelling of the digit, (3) pain with passive extension, and (4) excruciating tenderness over the course of the flexor tendon sheath. Flexor tenosynovitis may also occur without Kanavel signs, particularly in immunocompromised patients. In most cases, patients require urgent incision and drainage of the flexor tendon sheath. Broad-spectrum antibiotic coverage against staphylococci is initiated after cultures are obtained. Then, culture-specific antibiotics are given. (See Surgical therapy forthe details of surgical management.) (See also the eMedicine articles Tenosynovitis [in the Emergency Medicine section] and Flexor Tendon Anatomy and Infectious and Inflammatory Flexor Tenosynovitis [in the Orthopedic Surgery section].)

Septic arthritis usually results as a sequela after open skeletal trauma or from a bite wound. Patients with inflammatory arthritis are at increased risk for joint-space infections. Tenderness and swelling of the joint are signs of potential infection. Puncture wounds over the joint should suggest potential septic arthritis. The differential diagnosis includes gout, psoriatic arthritis flare, and systemic lupus erythematosus. Staphylococci and streptococci are most commonly isolated in septic joint cultures. Arthrotomy is the preferred treatment, as opposed to joint aspiration, which can be used to aid diagnosis. However, arthrotomy is required to adequately drain the infection. The interphalangeal (IP) joints (proximal and distal) can be accessed through a dorsal or midaxial incision. The collateral ligaments often must be released to allow access to the joint capsule. The metacarpophalangeal (MCP) joint can be accessed via a dorsal approach. A 10-day course of culture-specific antibiotics is required.  (See also the eMedicine articles Gout [in the Orthopedic Surgery section], Psoriatic Arthritis [in the Dermatology section], and Systemic Lupus Erythematosus [in the Emergency Medicine section].)

Osteomyelitis can occur from an acute event, such as a penetrating wound or open fracture, or as a late sequela of a fracture or other surgery. Patients with a history of diabetes or other immunocompromising conditions are at higher risk for osteomyelitis. Diagnosis of this condition is based on the signs seen with other infections: cellulitis, warmth, and tenderness. In addition, recurrent infections in the same location may be a sign of infection of the underlying bone. Laboratory studies and radiographs can assist in making the appropriate diagnosis (see Workup, Lab Studies and Imaging Studies). The treatment consists of debridement of the devitalized bone, as well as antibiotics, usually a prolonged course of 6 weeks. (See also the eMedicine article Osteomyelitis.)

Herpetic whitlow is a viral infection that is caused by the herpes simplex virus and that may resemble a felon or paronychia. These infections usually occur in medical or dental personnel. History is an important clue to the diagnosis. The patient first notices pain, then erythema before the development of the herpetic vesicle. The treatment of herpetic whitlow is nonoperative; therefore, differentiating these infections from bacterial felons and paronychia is important. The diagnosis can be confirmed by obtaining cultures of the vesicles. Overall, the infection has a self-limited course. The treatment consists of pain control. Topical antiviral agents have been recommended in patients who are immunocompromised. A 20% risk of reactivating the herpetic infection has been reported. (See also the eMedicine article Herpetic Whitlow.)

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• References

Lab Studies

• Complete blood cell (CBC) count: An elevated white blood cell count can indicate the presence of infection. In the case of particularly severe infections, the CBC test may provide a measure of the patient's progress.
• Prothrombin time (PT) and activated partial thromboplastin time (aPTT): Obtain these tests before surgical treatment in patients who are receiving long-term anticoagulant therapy.
• Glucose level: Check glucose levels in all patients with a history of diabetes. In those patients with active infections, blood-glucose levels are often elevated and difficult to control. Furthermore, blood-glucose control is important for wound healing. It is also important to check the glucose levels of any patient who has a history of frequent or particularly severe infections to rule out occult diabetes.
• Chemistry panel: In general, check the chemistry panel of patients who have a history of dehydration (secondary to vomiting or sepsis). Check the chemistry panel of elderly patients before surgery.
• Erythrocyte sedimentation rate (ESR): The ESR is elevated in cases of septic arthritis and osteomyelitis. However, patients with inflammatory arthritis may have elevated ESRs without infection.
• If there is a clinical suspicion of septic arthritis, a joint aspirate should be sent for Gram staining, culturing, and sensitivity testing. In addition, cell count assessment, glucose and protein level determinations, and crystal analysis help in distinguishing between an infected joint and a joint with inflammatory arthritis or gout/pseudogout. (See also the eMedicine article Gout and Pseudogout.)

Imaging Studies

• Plain radiographs (3 views of the hand) are important to rule out the presence of foreign bodies, fractures, and subcutaneous air, which could indicate gas gangrene or acute or chronic osteomyelitis.
• Magnetic resonance imaging (MRI) may be helpful for assessing soft-tissue abscess(es) and osteomyelitis.
• Ultrasonography may reveal soft-tissue abscess(es).
• Bone scanning, indium-111 (¹¹¹In) radionuclide studies, or computed tomography (CT) scanning may be useful for evaluating osteomyelitis.

TREATMENT

Section 6 of 10  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• References

Medical therapy

A few important guidelines assist in the management of hand infections. First, cellulitis must be treated with antibiotics. Most hand infections are caused by S aureus,⁴ and therefore, a first-generation cephalosporin (eg, cephalexin) is usually the first drug of choice. However, the potential exists for infections with different organisms. In fact, an increase in the incidence of community-acquired methicillin-resistant staphylococcal (MRSA) infections has been reported.^{5, 6, 7, 8}

Animal bites require bacterial coverage that is particular to the offending animal. Human bites require coverage for Eikenella corrodens; penicillin and a first-generation cephalosporin are appropriate choices in these cases. Cat bites require coverage for Pasteurella multocida⁹; appropriate antibiotics include IV ampicillin/sulbactam or oral amoxicillin clavulanate. Usually, oral antibiotics are sufficient as initial treatment. Many medical professionals recommend an initial, limited wound irrigation in the emergency department or in the outpatient clinic. Consider IV antibiotics in patients in whom cellulitis fails to resolve with oral antibiotics. In all cases, the final antibiotic coverage should be guided by culture and sensitivity results. Patients with a history of immunocompromise (including those with diabetes) should initially be treated with IV antibiotics. (See also the eMedicine articles Bites, Animal, Bites, Human, and Cellulitis [in the Emergency Medicine section] and Pasteurella Multocida Infection [in the Infectious Diseases section].)

Fungal infections can occur in or under the skin. Cutaneous fungal infections, or tinea, are treated with topical agents such as miconazole or clotrimazole. The most common subcutaneous infection is sporotrichosis; this condition can appear with an ulcerative lesion, along with lymphadenopathy. Gardeners are most commonly infected. Oral itraconazole for 3-6 months is the current recommended course of treatment. Fungal abscesses or disseminated fungal infections can occur and are usually found in immunocompromised patients.² (See also the eMedicine article Sporotrichosis.)

Surgical therapy

As a rule, all abscess cavities must be drained. Antibiotics alone are not effective in treating pus. If the patient does not improve with antibiotics, suspect undrained pus or a foreign body. Immunocompromised patients should always receive IV antibiotics.

Preoperative details

Before surgery, obtain a thorough patient history, and perform a thorough physical examination. The operating surgeon must counsel each patient about the appropriate risks and benefits of each procedure. Furthermore, consent for sufficient latitude in performing the procedure (eg, possible amputation) is necessary. Patients should always be preoperatively informed that further operations may be necessary.

Intraoperative details

In the operating room, perform all explorations and debridements under tourniquet control. The extremity should be exsanguinated by gravity. Obtain wound cultures before the administration of antibiotics; then administer a dose of perioperative antibiotics because of the likelihood of a transient bacteremia after debridement.

Intraoperative cultures should include tests for aerobic, anaerobic, fungal, mycobacterial, and atypical mycobacterial organisms. Debride all devitalized tissue, and thoroughly irrigate all wounds. Treat larger wounds with pulse lavage and antibiotic irrigation. A repeat exploration and a second operative irrigation and debridement are necessary for certain wounds.

Flexor tenosynovitis

At the time of the operation, an incision is made in the distal area of the palm over the proximal end of the flexor sheath. The sheath is incised, and the presence of cloudy fluid or pus in the sheath is a clear indication of tenosynovitis. A second midaxial incision is made distally in the digit to provide access to the distal end of the tendon sheath. An irrigation catheter is placed through the sheath, and continuous irrigation of the sheath (usually with saline or antibiotic solution) is performed for 48 hours.

Be cognizant of the presence of digital swelling due to overly aggressive irrigation. It is possible to cause digital necrosis. If signs of infection have improved, the drainage system can be removed, and the patient should receive a course of antibiotics with elevation of the affected area.

Deep palm and web-space infections

The incision should be centered over the area of fluctuance. Incisions can be made along the palmar creases when possible. In the case of deep-space infections, wide exposure is important. The palmar fascia is incised, and the common digital nerves and vessels should be identified and protected when possible. A palmar and dorsal incision may be necessary, particularly in the case of collar button abscesses.

Septic arthritis

Arthrotomy is necessary to adequately treat septic arthritis. For the MCP joint, a dorsal incision can be used. The extensor mechanism is split in the midline, and the joint capsule is incised. In the case of proximal IP joint infections, a dorsal incision can be used, but when dividing the extensor tendon, one must be careful to preserve the central slip. Alternatively, a midaxial incision can be made. The joint is entered by incision of the accessory collateral ligament.

The joint space must be copiously irrigated, and the fibrinous and synovial debris is debrided. The wound can be packed to allow for continuous bedside irrigation, or if joint debridement has been adequate, the wound can be loosely closed.

Osteomyelitis

In cases of chronic osteomyelitis, surgical debridement is required. The sequestrum or devitalized bone must be removed. Similarly, in cases of acute osteomyelitis, debridement of the denuded bone is important for obtaining microbiologic cultures and for treatment. Once acute and chronic infections have been resolved, bony reconstruction may be necessary.

Postoperative details

Immobilization, with splinting of the hand in the position of safety (wrist extension of 15-30°, MCP flexion of 70-90°, and IP extension), is important in reducing joint contractures. Furthermore, elevation is a critical aspect of hand infection management. Often, adequate elevation and immobilization require the patient's hospitalization. Once the infection resolves, patients should begin early mobilization therapy. The patient should begin range-of-motion exercises and be seen by a hand therapist as soon as possible to minimize postinfection stiffness.

Follow-up

Patients require close follow-up for the first several weeks after the infection. The surgeon should remain vigilant for any recurrence of infection and for appropriate compliance with wound care and hand therapy.

COMPLICATIONS

Section 7 of 10  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• References

Most complications from hand infections result from inadequate treatment. Inadequacies in treatment can be life-threatening in patients who are immunocompromised.¹ Joint contracture from prolonged immobilization can be functionally devastating.

Recurrent infections or polymicrobial infection of the hand frequently complicates the care of the immunocompromised patient.^{1, 5, 10}

OUTCOME AND PROGNOSIS

Section 8 of 10  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• References

Once the infection resolves, aggressive hand therapy regimens should be started. Swelling from the infection itself and prolonged immobilization lead to the significant formation of adhesions and joint stiffness. Encourage patients not to guard their hands but, rather, to use them as much as possible. This step is particularly crucial if the patient has undergone surgical debridement, including treatment for tenosynovitis. If the hand infection has been treated appropriately with measures such as eradication of the abscess and devitalized tissue, the risk of recurrence is minimal. Certain infections (eg, herpetic whitlow), however, have a 20% recurrence risk.

FUTURE AND CONTROVERSIES

Section 9 of 10  

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• References

Hand infections will remain to be a routine problem encountered by emergency physicians, primary care physicians, and hand specialists.⁴ The basic principles of management outlined in this article will continue to be crucial to successful treatment. The clinician needs to be aware of the increasing incidence of infections with more virulent microorganisms.⁶ Community-acquired infections with MRSA are encountered in nearly every area of the body, and the hand is no exception.^{7, 8} In addition, with the growing number of cancer survivors, transplant patients, and patients living with the human immunodeficiency virus (HIV), the surgeon can anticipate treating more complex polymicrobial hand infections.

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Indications
• Relevant Anatomy
• Workup
• Treatment
• Complications
• Outcome and Prognosis
• Future and Controversies
• References

1. Klein MB, Chang J. Management of hand and upper-extremity infections in heart transplant recipients. Plast Reconstr Surg. Sep 2000;106(3):598-601. [Medline].
2. Moran SL, Strickland J, Shin AY. Upper-extremity mucormycosis infections in immunocompetent patients. J Hand Surg [Am]. Sep 2006;31(7):1201-5. [Medline].
3. Benson LS, Edwards SL, Schiff AP, Williams CS, Visotsky JL. Dog and cat bites to the hand: treatment and cost assessment. J Hand Surg [Am]. Mar 2006;31(3):468-73. [Medline].
4. Houshian S, Seyedipour S, Wedderkopp N. Epidemiology of bacterial hand infections. Int J Infect Dis. Jul 2006;10(4):315-9. [Medline].
5. Karanas YL, Bogdan MA, Chang J. Community acquired methicillin-resistant Staphylococcus aureus hand infections: case reports and clinical implications. J Hand Surg [Am]. Jul 2000;25(4):760-3. [Medline].
6. Bubacz MR. Community-acquired methicillin-resistant Staphylococcus aureus: an ever-emerging epidemic. AAOHN J. May 2007;55(5):193-4. [Medline].
7. Bach HG, Steffin B, Chhadia AM, Kovachevich R, Gonzalez MH. Community-associated methicillin-resistant Staphylococcus aureus hand infections in an urban setting. J Hand Surg [Am]. Mar 2007;32(3):380-3. [Medline].
8. Kiran RV, McCampbell B, Angeles AP, et al. Increased prevalence of community-acquired methicillin-resistant Staphylococcus aureus in hand infections at an urban medical center. Plast Reconstr Surg. Jul 2006;118(1):161-6; discussion 167-9. [Medline].
9. Westling K, Farra A, Cars B, et al. Cat bite wound infections: a prospective clinical and microbiological study at three emergency wards in Stockholm, Sweden. J Infect. Dec 2006;53(6):403-7. [Medline].
10. Dellinger EP, Wertz MJ, Miller SD, Coyle MB. Hand infections. Bacteriology and treatment: a prospective study. Arch Surg. Jun 1988;123(6):745-50. [Medline].
11. Downs DJ, Wongworawat MD, Gregorius SF. Timeliness of appropriate antibiotics in hand infections. Clin Orthop Relat Res. Aug 2007;461:17-9. [Medline].
12. Neviasser, RJ. Acute infections. In: Green DP, Pederson WC, Hotchkiss RN, eds. Green's Operative Hand Surgery. Vol 1. 4^th ed. Philadelphia, Pa: Churchill-Livingstone; 1999:1033-47.
13. Wheeler DR. Supportive flexor tenosynovitis. In: Blair WF, Steyers CM, eds. Techniques in Hand Surgery. Vol 1. Baltimore, Md: Williams & Wilkins; 1996.

Article Last Updated: Oct 22, 2007