Hi, I'm Purva Shah from the University of Pennsylvania and the Children's Hospital of Philadelphia. We're running a little bit behind, but we've covered a little bit of what I was going to talk about anyway, so I'll try to make up some time and get you guys all to cocktails or dinner. So, guiding principles with hand infection. Hand infections can result in severe disability, including stiffness, contractures, and amputation in some cases. In most close-space infections, antibiotics alone are not going to supplant the need for expedient, proper surgical intervention. So, early diagnosis, expedient IND are obviously important. You want to examine the extremity looking for pain, increased temperature, erythema, tenderness. You want to recognize fluctuants, lymphangitis, and lymphadenopathy. When you're looking at erythema, I find it useful, as I'm sure most of you do, to mark the borders of the erythema so you can assess progression or regression. Routine laboratory studies are important, but are not always reliable, so most of us are in the habit of obtaining a CBC, an ESR, a CRP, et cetera. It's important to understand that a CRP or an elevation in body temperature isn't even there in the majority of cases. In a review of 418 hand patients with infection, only 25% of them had elevated body temperature or CRP. Fifty percent of them will have an alteration in ESR, which may be a little bit more reliable of a test. You want to obtain radiographs in selected cases to evaluate for septic arthritis, osteomyelitis, gas within the soft tissues, or possible fracture. I'm going to skip through a little bit about the common infecting organisms. We elaborated on earlier in the session about the importance of MRSA. At least in recent series, the emergence of MRSA continues to increase. And you can expect that about 60% of hand infections will involve MRSA, depending on your specific hospital profile. The lesions in MRSA have a characteristic dermacrotic appearance, which can look like a spider bite. You see a spider bite on the top right, and then an MRSA lesion in the bottom. You can see the area of potential confusion. With surgical intervention, you want to plan your incision for potential extension. And you want to plan the incision so that you minimize unnecessary exposure of vessels, nerves, and tendons, as you're most likely going to be leaving a portion or significant segment of the wound open. You want to excise all necrotic tissue and then copiously irrigate. If it's an acute infection, you can feel comfortable getting a gram stain and just an aerobic and anaerobic culture, but if it's chronic, if there's some potential for immunosuppression in the host, then you really want to be wary, as we've discussed through Dr. Jebsen and Bobby Chhabra, for atypical infections, including mycobacteria. You want to send for fungal cultures and then stain for acid-fast bacilli. We'll skip through antibiotics. So cellulitis is obviously a common presenting infection of the hand. Staph aureus and beta-hemolytic streptococcus are the most common pathogens. You're going to see lymphangetic streaking more commonly with beta-hemolytic streptococcus. Since this is a non-puss-forming infection, you want to treat non-surgically with antibiotics. However, if you're not seeing your patient turn around in that first 24, 36 hours, you really want to be suspicious of a missed abscess and order that early ultrasound or MRI so that you're not chasing your wheel with the infection. Subcutaneous abscess can obviously be present in that kind of patient. This often will follow a puncture wound. Staph aureus is the most common organism. Expedient IND is obviously important. Gram stain and cultures. And then empiric antibiotics based on the hospital profile, but certainly covering for MRSA so that you're not in an arms race in terms of antibiotics and chasing the infection around. Acute peronichia is one of the most common infections of the hand. And this is an infection involving the peronichium or the eponichial fold of the nail plate. There are high-risk activities in patients including nail biting and manicures. This is often polymicrobial. However, staph aureus is still the most common organism. You're going to see erythema, swelling, and tenderness adjacent to the nail. It's possible that there'll be an abscess along the nail fold. Rarely, but sometimes you'll see involvement of both the peronichium and the eponichial fold. If a patient has had a recurrent acute peronichia or they aren't responding to conventional treatment, you want to make sure to get a radiograph to assess for osteomyelitis or underlying bone infection. If a patient presents early, this can be treated non-surgically. Warm soaks in dilute solution, resting of the affected digit, and oral antibiotics. There is no data in the literature to support this. I think many of us do this. But there's not really evidence to support how effective it is. More typically, a patient's going to have an abscess and then you're going to drain it usually in the office. You want to aim the blade away from the matrix to avoid subsequent nail plate deformity. In my practice, I'll routinely in this situation remove a portion of the nail or the entire nail to prevent infection, particularly if the infection extends deep to the nail plate. And then you want to stent the eponichial fold. Oral antibiotics for 7 to 10 days after procedure is usually sufficient. Chronic peronichia is important to distinguish from acute peronichia. This is a chronic inflammation accompanied by repeated episodes of inflammation and drainage. And this is often secondary to recurrent or frequent water immersion. So think about dishwashers, swimmers, medical personnel, kids that suck on their fingers repeatedly. Infection is polymicrobial, often involves candida albicans, gram-positive cocci, gram-negative rods, and occasionally mycobacterial species. You're going to look for an indurated, rounded eponichium. And the patient will report a history of episodic erythema and drainage. The nail plate's going to look different in most cases. And I would say 85 to 90% of cases you're going to see thickening or grooving of the nail plate. Treatment for chronic peronichia, you can attempt conservative treatment by reducing their water exposure using topical or oral antimicrobial agents. However, in most cases, refer to a hand surgeon, eponichial, marsupialization is the treatment of choice. You want to excise a 3-millimeter crescent of tissue, protect the germinal matrix when you're doing this. It's really important to assess for nail plate deformity. If there's nail plate deformity and you leave the nail on, there's a higher chance of recurrence. So you want to remove the nail plate if there's any evidence of deformity. Oral antibiotics for 10 to 14 days following the procedure. Patients should understand that there's a high recurrence rate with continued environmental exposure. And it can take a long while for the nail to grow back. Aphelan is obviously another common infection that all of us treat commonly. It represents probably 15 to 20% of hand infections, usually after penetrating trauma. Again, think staphylococcus aureus. Many of us have seen this progress to flexor tenosynovitis or osteomyelitis if there's a treatment delay. Patients will present with throbbing pain and tension and swelling in the distal pulp of their fingertip. You want to look for exquisite tenderness on exam. This will never really extend past the DIP crease. Radiographs should be obtained in that recalcitrant case that's been hanging around for a while to look for osteomyelitis or a foreign body. A surgical decompression can be performed under digital block. You want to use an appropriate incision for the drainage. So you've got to go where the infection is. But you, if at all possible, want to avoid the pinch or border surfaces. I personally prefer unilateral longitudinal incision about five millimeters distal to the DIP crease and extending towards the fingertip. You want to preserve the digital nerves and uninvolved septa. If you really release all the way across, even if the extension does, even though the infection doesn't extend to the other side of the finger, you're going to really destabilize the pulp of the fingertip, which can be uncomfortable for patients. If you have a patient where the fingertip pulp is unstable, it'll usually settle down within six to 12 months. So you can just follow that. Most patients will have some residual pulp deformity or atrophy. Flexor tenosynovitis often occurs after a penetrating trauma, staph aureus again, cannabis signs I'm not going to belabor. The important thing to understand is that cannabis signs don't present uniformly across patients. The most reliable signs are pain with passive extension of the digit and fusiform swelling. But not all patients will present with the majority of signs. Particularly in the thumb and the small finger, where the radial and ulnar bursa will allow for auto decompression of the flexor tendon sheets, you're going to look for more subtle findings. Very, very few patients can be treated non-surgically. If they're presenting in the first 24 hour of symptom onset, they have less than one or two of the cannabis signs, and they have really mild pain. You could try them on intravenous antibiotics, monitor them really closely. If they're not improving by the next morning, you really should be thinking about surgical intervention. There's a variety of incisions that you can use, many of which are effective. You want to avoid Brunner incisions, as this could potentially lead to downstream skin margin loss or exposure of the flexor tendons themselves. I personally prefer small incisions and intermittent tendon sheath irrigation. I'll make an oblique incision over the A1 pulley, and then a mid-axial incision just to the A4 pulley. I'll enter the flexor tendon sheath just dorsal to Cleveland's ligament. I usually irrigate with a number five pediatric feeding tube. And then I'm very careful about discontinuing the irrigation intraoperatively if I'm seeing fluid extravasate into the digit where you're adding to the amount of edema and swelling, potentially finger necrosis. Multiple studies, including one in 2002, demonstrate equal efficacy between a closed irrigation technique and a more open-debris mod. You can expect a rapid improvement in your patients. However, the ultimate outcome is less good than all of us would like to admit. The typical patient is going to have an 80% recovery of total active motion, but there are patients who lose 50% of their motion. Risk factors for poor outcomes, including joint contracture and amputation, are age more than 43, diabetes, other risks for immunocompromise. Presence of subcutaneous purulence is a big issue, and that requires more of an open procedure. Digital ischemia is the biggest concern, and it has a 59% amputation rate in the setting of flexor tenosynovitis. And polymicrobial infection can result in a poor outcome. Deep space infections of the hand come in many varieties. There are potential spaces in the hand and the forearm, the thenar space, the mid-palmar space, hypothenar space, and parona space. These potential spaces lie between muscle fascial planes and are usually inoculated with a puncture wound. Staph aureus, again, the most common. This is a diagram illustrating the thenar and the mid-palmar space. You can see the thenar spaces between the adductor pollicis and then the index flexor tendons. The mid-palmar space lies between the volar palmar interossei and then the flexor digitorum profundus tendons. A thenar absence often happens with penetrating injury. Patients will present with their thumb held in abduction to minimize pressure in the abscess cavity. This is the most common deep space infection. It's important to recognize that the abscess often tracks dorsally between the transverse and oblique heads of the adductor pollicis. How you drain this is dealer's choice. Dorsal incision, volar incision are combined. I usually vary based on the presentation and the patient. When you're in your volar approach, you want to look for the recurrent motor branch of the median nerve to avoid iatrogenic injury. Mid-palmar space infections are much less common. We talked about the boundaries. The hallmark sign is a loss of the normal palmar concavity, and that's why it's sometimes missed. Sometimes patients will present with more obvious dorsal findings than volar findings. Incisions really are variable, either L-shaped or straight transverse. I typically will use a straight transverse incision. Here you're going to look out for the superficial palmar arch and then branches of the digital nerve. Peroneus space infections are in the distal volar forearm. The peroneus space is between the pronator quadratus and then the sheath of the flexor digitorum profundus tendons. It's in continuity with the mid-palmar space, and as I mentioned before, the radial and ulnar bursa are going to potentially not directly communicate, but rupture into peroneus space. So you can develop a horseshoe abscess between the small finger and the radial bursa via peroneus space. Septic arthritis, Dr. Chhabra talked about, so I'm going to skip forward a little bit. I'm just going to mention a few points. The wrist is most commonly involved, and the second most common small joint is the PIP joint. DIP septic arthritis can occur in the setting of a draining mucous cyst. When you're thinking about aspiration and working these patients up, I find that wrist aspiration works well. Small joint aspiration doesn't work very well. If you're aspirating a wrist and you can't get any fluid back, put in one or two cc's of normal saline and lavage the joint. Classically, we're all taught that 50,000 white cells per cubic millimeter is an indication of septic arthritis, but the best data suggests that that has a very low sensitivity, and a number as small as 17,500 will have, you will find patients with septic arthritis, and that will have a sensitivity of approximately 80%, still with a specificity of 60-some percent. So be careful on what you set as your cell count threshold for draining a septic arthritis. Serial aspiration for small joints is not effective, so this is something that needs surgery. If it's a small joint, likely open. If it's a wrist, open or arthroscopic, and Dr. Chhabra reviewed the data at Mayo Clinic comparing arthroscopic and open. Finger amputation or arthrodesis, despite trying to get to these early, is not uncommon, and 25% of patients with a septic arthritis of the PIP joint or the MCP joint are going to have some downstream corrective surgery. Osteomyelitis, we've talked about in detail, so I'm going to kind of skip past that. Herpetic Whitlow is a HSV infection of the finger. The index and the thumb are the most commonly involved. This will, you'll see this in children and then also healthcare workers. If it presents in a child, you're almost always going to see HSV-1. If it presents in an adult, a dental hygienist, a healthcare worker, you're going to see HSV-1 or HSV-2. It has a 2-14 day incubation period. It has a hallmark prodromal pain that you're going to see. Patients will present with 1-2 millimeter clear vesicles that tend to creep and coalesce over time, as you're seeing in the picture in the bottom right. Diagnosis is through a Sank smear. The infection is almost always self-limited. Acyclovir should really only be used for recurrent cases. Patients are contagious for two weeks, so you want to make sure that the site of infection is kept covered to prevent contamination. Misdiagnosis is probably the biggest problem. Patients are often treated for a bacterial abscess. Surgical intervention can result in superinfection, which really will result in a potential morbidity for the patient. Twenty percent of patients will have recurrence. Necrotizing fasciitis, Dr. Traber talked about. So just going to close up with some specific situations. Animal bites most often is going to be from a dog. Second most common is cat. The vast majority of bites are from a dog, but the vast majority of bites that we see are from a cat because the majority of hand infections from animal bite come from a cat, usually because of the sharp tooth and the depth of the penetration. Pasturella is the specific bacteria you want to look for, although these are often polymicrobial. If a patient presents after a cat bite, no real obvious sign of infection. At the very least, you want to consider a bedside IND in oral antibiotics, Augmentin in my practice. Human bites are often misdiagnosed or underreported. Obviously, in the situation of a fight bite, patients don't often report the mechanism. In a fight bite, the hand strikes another individual's mouth with a clenched fist. Deep structures can be involved, including tendon, joint capsule, cartilage, bone. There's 50 species of bacteria in the typical human mouth. Eichenelic is the one that you want to specifically remember. Fight bites often result to the long finger and the ring finger more commonly than the index. Because the MCP joint is in a flexed posture, the level of tendon injury is usually more proximal than the level of joint penetration. If there is clear evidence of an infection at the time of presentation, you want to consider an urgent IND. If there's not an infection present at the time of presentation to the ER, there's really no data to suggest you have to go to the OR. And so whether you perform wound care in the ER or the OR is your choice. But if it's infected, you've got to go. Radiographs are important preoperatively to assess for a foreign body, like a tooth. When you're in the joint, you really want to look for that loose body or foreign body. 6% of patients are going to have a loose cartilage fragment that you want to make sure you identify and remove. Marine organisms, Dr. Jebson spoke about, so we'll skip through those. In summary, the emergence of community-acquired MRSA is really a game changer for all of us. And it necessitates appropriate empiric coverage from the outset. You want to consider the mechanism of the infection. And when you have a human bite, an animal bite, or an aquatic injury, the patient may require a different empiric antibiotic or more aggressive treatment. Early diagnosis is important to avoid permanent contracture and loss of function. Thank you.

hand infections

treatment options

MRSA

surgical intervention

diagnosis