Inflammatory and infectious skin diseases in line-field confocal optical coherence tomography: state of the art.

Line-field confocal optical coherence tomography (LC-OCT) is a new non-invasive dermatological imaging device. We summarized the available data on the use of LC-OCT for inflammatory and infectious diseases. In February 2023, we searched for all articles concerning the use of LC-OCT in inflammatory and infectious diseases. A total number of 14 papers were found and evaluated, and relevant information was extracted. LC-OCT can reveal architectural changes in the skin. Inflammatory cells are barely visible. It can highlight the level of fluid accumulation, the thickness of different epidermal layers, and the presence of ''foreign bodies'' such as parasites.

Does Point-of-Care Ultrasound Affect Outcomes in Pediatric Patients with Skin and Soft Tissue Infections?

OBJECTIVE: There is increasing evidence for the use of point-of-care ultrasound (POCUS) in pediatric patients with skin and soft tissue infections (SSTI), but there is a lack of sufficient data on its impact on SSTI outcomes. The objective of this study was to determine whether POCUS use is associated with fewer complications after discharge from the pediatric emergency department. METHODS: This was a prospective cohort study in patients presenting to the emergency department with SSTI between the ages of 2 months and 19 years old. Adverse outcomes included hospitalization after discharge, change in antibiotics, subsequent procedures, or reevaluation by a medical professional. Outcome information was obtained 1 week later. Descriptive statistics and χ2 tests were used. RESULTS: Of 456 patients screened, 250 were enrolled. POCUS was performed on 113 (45%) patients. The median age was 5 years, with more females in the non-POCUS group compared with the POCUS group (58% vs. 52%). Cellulitis without abscess was more commonly diagnosed in the POCUS group than in the non-POCUS group (26% vs 14%, P = 0.02.) The patients in the non-POCUS group were more likely to undergo incision and drainage than those in the POCUS group (62% vs 45%, P = 0.008). Overall, a greater number of patients in the POCUS group did not undergo any procedure (45% vs 27%, P = 0.003). The outcomes at 1 week did not differ significantly between the two groups. CONCLUSIONS: POCUS use may lead to fewer procedures, but it does not lead to significantly better outcomes. Large randomized controlled trials are needed to confirm or refute our findings.

Reflectance confocal microscopy for the diagnosis of skin infections and infestations.

Reflectance confocal microscopy (RCM) is a noninvasive real-time imaging technique that has been widely used for the diagnosis of skin cancer. More recently, it has been reported as a useful tool for the diagnosis and management of several inflammatory and infectious skin disorders. This article provides an overview of the current available applications of RCM use in cutaneous infections and infestations. PubMed was used to search the following terms in various combinations: reflectance confocal microscopy, skin, hair, nail, infection, parasitosis, mycosis, virus, bacteria. All papers were accordingly reviewed. In most cutaneous infections or infestations, the main alterations are found in the epidermis and upper dermis, where the accuracy of confocal microscopy is nearly similar to that of histopathology. The high resolution of this technique allows the visualization of most skin parasites, fungi, and a few bacteria. Although viruses cannot be identified because of their small size, viral cytopathic effects can be observed on keratinocytes. In addition, RCM can be used to monitor the response to treatment, thereby reducing unnecessary treatments.

Cytologic, histologic, microbiologic, and electron microscopic characterization of a canine Prototheca wickerhamii infection.

An adult dog was presented for chronic cough and a recent development of ulcerated, erythematous nares with nasal discharge. Cytology of enlarged peripheral lymph nodes revealed many intracellular and extracellular organisms. These round or rarely oval organisms measured approximately 5-9 µm in diameter and frequently contained several globular structures, ranging from deeply basophilic to magenta. A thin, clear halo was present. Smaller 1-2 µm, magenta forms were also observed. Fungal culture yielded small, wet, raised, irregularly shaped, white to pale tan colonies. Microbiologic staining of cultured material revealed features suggestive of algae. Histopathology of the lymph nodes revealed marked granulomatous inflammation with intralesional algal organisms suggestive of Prototheca. Electron microscopic findings were also consistent with protothecosis. Polymerase chain reaction, followed by direct DNA sequencing, identified the organism as Prototheca wickerhamii. A brief literature review discussing protothecosis in veterinary medicine is included.

Intravital imaging of skin infections.

Intravital imaging of cutaneous immune responses has revealed intricate links between the skin's structural properties, the immune cells that reside therein, and the carefully orchestrated migratory dynamics that enable rapid sensing and subsequent elimination of skin pathogens. In particular, the development of 2-photon intravital microscopy (2P-IVM), which enables the excitation of fluorescent molecules within deep tissue with minimal light scattering and tissue damage, has proven an invaluable tool in the characterization of different cell subset's roles in skin infection. The ability to visualize cells, tissue structures, pathogens and track migratory dynamics at designated times following infection, or during inflammatory responses has been crucial in defining how immune responses in the skin are coordinated, either locally or in concert with circulating immune cells. Skin pathogens affect millions of people worldwide, and skin infections leading to cutaneous pathology have a considerable impact on the quality of life and longevity of people affected. In contrast, pathogens that infect the skin to later cause systemic illness, such as malaria parasites and a variety of arthropod-borne viruses, or infection in distant anatomical sites are a significant cause of morbidity and mortality worldwide. Here, we review recent advances and seminal studies that employed intravital imaging to characterize key immune response mechanisms in the context of viral, bacterial and parasitic skin infections, and provide insights on skin pathogens of global significance that would benefit from such investigative approaches.

High accuracy of recognition of common forms of folliculitis by dermoscopy: An observational study.

BACKGROUND: Clinical differentiation of folliculitis types is challenging. Dermoscopy supports the recognition of folliculitis etiology, but its diagnostic accuracy is not known. OBJECTIVE: To assess the diagnostic accuracy of dermoscopy for folliculitis. METHODS: This observational study included patients (N = 240) with folliculitis determined on the basis of clinical and dermoscopic assessments. A dermoscopic image of the most representative lesion was acquired for each patient. Etiology was determined on the basis of cytologic examination, culture, histologic examination, or manual hair removal (when ingrowing hair was detected) by dermatologist A. Dermoscopic images were evaluated according to predefined diagnostic criteria by dermatologist B, who was blinded to the clinical findings. Dermoscopic and definitive diagnoses were compared by dermatologist C. RESULTS: Of the 240 folliculitis lesions examined, 90% were infections and 10% were noninfectious. Infectious folliculitis was caused by parasites (n = 71), fungi (n = 81), bacteria (n = 57), or 7 viruses (n = 7). Noninfectious folliculitis included pseudofolliculitis (n = 14), folliculitis decalvans (n = 7), and eosinophilic folliculitis (n = 3). The overall accuracy of dermoscopy was 73.7%. Dermoscopy showed good diagnostic accuracy for Demodex (88.1%), scabietic (89.7%), and dermatophytic folliculitis (100%), as well as for pseudofolliculitis (92.8%). LIMITATIONS: The diagnostic value of dermoscopy was calculated only for common folliculitis. Diagnostic reliability could not be calculated. CONCLUSION: Dermoscopy is a useful tool for assisting in the diagnosis of some forms of folliculitis.

Ultrasound features of purulent skin and soft tissue infection without abscess.

PURPOSE: Ultrasound (US) aids clinical management of skin and soft tissue infection (SSTI) by differentiating non-purulent cellulitis from abscess. However, purulent SSTI may be present without abscess. Guidelines recommend incision and drainage (I & D) for purulent SSTI, but US descriptions of purulent SSTI without abscess are lacking. METHODS: We retrospectively reviewed pediatric emergency department patients with US of the buttock read as negative for abscess. We identified US features of SSTI with adequate interobserver agreement (kappa > 0.45). Six independent observers then ranked presence or absence of these features on US exams. We studied association between US features and positive wound culture using logistic regression models (significance at p < 0.05). RESULTS: Of 217 children, 35 patients (16%) had cultures positive for pathogens by 8 h after US and 61 patients (32%) had cultures positive by 48 h after US. We found kappa > 0.45 for focal collection > 1.0 cm (κ = 0.57), hyperemia (κ = 0.57), swirling with compression (κ = 0.52), posterior acoustic enhancement (κ = 0.47), and cobblestoning or branching interstitial fluid (κ = 0.45). Only cobblestoning or interstitial fluid was associated with positive wound cultures in logistic regression models at 8 and 48 h. CONCLUSIONS: Cobblestoning or interstitial fluid on US may indicate presence of culture-positive, purulent SSTI in patients without US appearance of abscess. Although our study has limitations due to its retrospective design, this US appearance should alert imagers that the patient may benefit from early I & D.

Common Skin Conditions in Children: Skin Infections.

Skin infections account for a significant subset of dermatologic conditions of childhood. Common cutaneous viral infections in children include warts, molluscum contagiosum, hand-foot-and-mouth disease, and herpes simplex. Although viral infections are self-limited and often only mildly symptomatic, they can cause anxiety, embarrassment, and health care use. Recognition of their common and atypical presentations is necessary to differentiate them from other skin conditions of similar morphology. Impetigo, cellulitis, and abscess comprise the majority of childhood bacterial skin infections and are treated with topical or systemic antibiotics that cover group A Streptococcus and Staphylococcus aureus. Common fungal dermatologic infections in children are oral and genital candidiasis, tinea capitis, and tinea corporis. Management consists of topical and systemic antifungals, including nystatin, triazoles, terbinafine, griseofulvin, and imidazoles. Scabies is the most common parasitic skin infection among children and is managed with topical permethrin. Although serious illness is not common among children returning from international travel, patients presenting with fever and rash, especially petechial or hemorrhagic lesions, require thorough evaluation. Of the numerous reportable conditions that present with childhood rash, tick-borne illnesses, measles, rubella, and varicella are the most common.

Ultrasonography for the diagnosis of patients with clinically suspected skin and soft tissue infections: a systematic review of the literature.

BACKGROUND: In patients presenting with skin and soft tissue infections (SSTI), the use of ultrasound may lead to a more accurate distinction between cellulitis and abscess compared with clinical assessment alone. OBJECTIVES: This systematic review aims to determine the diagnostic accuracy of ultrasound for detecting skin abscesses. In addition, it aims to assess the impact of using ultrasound on management decisions in patients with SSTI. METHODS: We searched relevant electronic databases for primary studies including MEDLINE, EMBASE, and CINAHL. We searched conference proceedings, checked references of retrieved articles, and contacted field experts. Two reviewers assessed the quality of each full-text publication using a modified QUADAS-2 tool. RESULTS: Five studies (n=710) fulfilled our inclusion criteria. Four studies compared the diagnostic accuracy of ultrasound with clinical examination alone (n=584). Most studies reported an improvement in diagnostic accuracy. The sensitivity of ultrasound ranged from 89 to 98% and the specificity ranged from 64 to 88%. However, the sensitivity of clinical assessment ranged from 75 to 90% and the specificity ranged from 55 to 83%; most of these results did not reach statistical significance. Sensitivity was further improved in cases of indeterminate clinical assessment. Two studies (n=176) examined the impact of ultrasound on management decisions. Use of ultrasound has led to significant and appropriate changes in management decisions in 16 to 39% of patients. CONCLUSION: The use of ultrasound could potentially improve diagnostic accuracy and lead to improved management decisions in patients with SSTI, especially in cases of indeterminate clinical assessment. Most of our findings did not achieve statistical significance. Further research is required to confirm these findings.

High frequency ultrasound with color Doppler in dermatology.

Ultrasonography is a method of imaging that classically is used in dermatology to study changes in the hypoderma, as nodules and infectious and inflammatory processes. The introduction of high frequency and resolution equipments enabled the observation of superficial structures, allowing differentiation between skin layers and providing details for the analysis of the skin and its appendages. This paper aims to review the basic principles of high frequency ultrasound and its applications in different areas of dermatology.

Optimising the quality and outcomes of treatments for diabetic foot infections.

INTRODUCTION: Infection is the commonest foot complication that arises in people with diabetes and may lead to amputation and even death. The emergence of multidrug resistant bacteria, especially in Gram negative rods, may have a negative impact on the chances of cure in these patients. AREAS COVERED: We searched the Medline and Pubmed databases for studies using the keywords 'diabetic foot infection' and 'diabetic foot osteomyelits' from 1980 to 2016. Expert commentary: Much has been done in the field of diabetic foot infection regarding pathophysiology, diagnosis and treatment. The construction of multidisciplinary teams is probably the most efficient way to improve the patients' outcome. The rational use of antibiotics and surgical skills are essential in these potentially severe infections. Each case of diabetic infection deserves to be discussed in the light of the current guidelines and the local resources. Because of the overal poor outcome of these infections, prevention remains a priority.

High frequency ultrasound with color Doppler in dermatology

Abstract: Ultrasonography is a method of imaging that classically is used in dermatology to study changes in the hypoderma, as nodules and infectious and inflammatory processes. The introduction of high frequency and resolution equipments enabled the observation of superficial structures, allowing differentiation between skin layers and providing details for the analysis of the skin and its appendages. This paper aims to review the basic principles of high frequency ultrasound and its applications in different areas of dermatology.

Histologic features of granulomatous skin diseases.

Granulomatous disorders affecting the skin belong to a heterogeneous group of diseases, which were predominantly classified based on pathogenetic features. In infections diseases a granuloma is formed if an agent could not be eliminated by the immune system. Typical agents which cause granulomatous reactions are mycobacteria, fungal infections, especially extra European agent, which could effect the skin by, dissemination (e.g. histoplasmosis) or parasites, like leishmaniasis.

Ultrasound for the Evaluation of Skin and Soft Tissue Infections.

Skin and sott tissue infections, including abscesses and cellulitides, are common problems seen by physicians. The treatment of soft tissue infections varies depending on the depth of infection or the presence of a fluid collection requiring incision and drainage. Ultrasound is a valuable tool in the evaluation of skin and soft tissue infections, enhancing our ability to diagnose an abscess cavity or deeper infection and has been shown to be more reliable than clinical exam alone. The judicious use of ultrasound allows for more appropriate patient care and management of their underlying infection. It can prevent an unnecessary procedure or identify occult abscesses that may go on to develop a more severe infection requiring hospitalization. In this article,we discuss the utility of ultrasound as a diagnostic tool for skin and soft tissue infections, techniques to optimize scanning, and the potential drawbacks of its use.

Emergency ultrasound-assisted examination of skin and soft tissue infections in the pediatric emergency department.

OBJECTIVES: The objective was to evaluate the test characteristics of clinical examination (CE) with the addition of bedside emergency ultrasound (CE+EUS) compared to CE alone in determining skin and soft tissue infections (SSTIs) that require drainage in pediatric patients. METHODS: This was a prospective study of CE+EUS as a diagnostic test for the evaluation of patients 2 months to 19 years of age evaluated for SSTIs in a pediatric emergency department (ED). Two physicians clinically and independently evaluated each lesion, and the reliability of the CE for diagnosing lesions requiring drainage was calculated. Trained pediatric emergency physicians performed US following their CEs. The authors determined and compared the test characteristics for evaluating a SSTI requiring drainage for CE alone and for CE+EUS for those lesions in which the two physicians agreed and were certain regarding their CE diagnosis (clinically evident). The performance of CE+EUS was evaluated in those lesions in which the two physicians either disagreed or were uncertain of their diagnosis (not clinically evident). The reference standard for determining if a lesion required drainage was defined as pus expressed at the time of the ED visit or within 2 days by follow-up assessment. RESULTS: A total of 387 lesions underwent CE+EUS and were analyzed. CE agreement between physicians was fair (κ = 0.38). For the 228 lesions for which physicians agreed and were certain of their diagnoses, sensitivity was 94.7% for CE and 93.1% for CE+EUS (difference = -1.7%; 95% confidence interval [CI] = -3.4% to 0%). The specificity of CE was 84.2% compared to 81.4% for CE+EUS (difference = -2.8%; 95% CI = -9.7% to 4.1%). For lesions not clinically evident based on CE, the sensitivity of CE was 43.7%, compared with 77.6% for CE+EUS (difference = 33.9%; 95% CI = 1.2% to 66.6%). The specificity of CE for this group was 42.0%, compared with 61.3% for CE+EUS (difference = 19.3%; 95% CI = -13.8% to 52.4%). CONCLUSIONS: For clinically evident lesions, the addition of ultrasound (US) did not significantly improve the already highly accurate CE for diagnosing lesions requiring drainage in this study population. However, there were many lesions that were not clinically evident, and in these cases, US may improve the accuracy of the CE.

[Necrotizing cutaneous infections and Fournier's gangrene]. / Dermohypodermites bactériennes nécrosantes et fasciites nécrosantes (DBHN-FN) périnéales ou gangrène de Fournier.

Fournier's gangrene is a necrotizing infection of skin and soft tissue of the perineum. Several sources of contamination have been described: cutaneous, urological or anorectal. Anatomy of the perineum helps in the prediction of the extension of the infection. The bacterial flora (usually mixed aero-anaerobic flora) depends on the source of infection: gram-positive cocci (skin source) combined with gram-negative bacilli and anaerobes (urological or anorectal source). CT scan and echography are useful tools for the diagnosis without delaying surgery. In the diagnostic procedure and the management, proctological examination, retrograde uretrography, bowel and urine derivation should be discussed.

[Ultrasound skin findings in HIV infection by imaging with 7.5 MHz linear transducers]. / Sonographische Befunde der Haut bei HIV-Infektion in der Darstellung mit 7,5-MHz-Linearschallköpfen.

Sonography is an important tool in aiding the diagnosis of tumor-like and cystic findings in the skin and soft tissues. This is also true in patients with HIV infection and AIDS. While sonography of the skin often is performed with 20-MHz transducers, also lower-frequency devices which are more readily available contribute substantially to dermatologic diagnoses. The domain of skin sonography are tumors; in the special context of AIDS, Kaposi's sarcoma and lymphomas are of major interest. The characteristic appearance of Kaposi's tumors is a spindle-shaped outline with low echogenicity and relative homogenicity. The tumor volume is easily established using measurements in two directions. Shrinkage of the volume after therapy, e.g. chemotherapy, may be documented in a more objective manner as compared to subjective rating of nodularity. Several characteristic images of Kaposi's sarcoma, lymphoma, lymph nodes, lipoma, and cysts are demonstrated in the paper.

Osteolytic lesions and bacillary angiomatosis in HIV infection: radiologic differentiation from AIDS-related Kaposi sarcoma.

Bacillary angiomatosis is a newly recognized multisystem bacterial infectious disease seen in the setting of human immunodeficiency virus (HIV) infection. The disease is marked by cutaneous vascular lesions that contain a bacterium similar to the cat scratch disease bacillus. Antibiotic therapy leads to the resolution of both cutaneous and systemic manifestations. Of 17 HIV-infected patients with cutaneous lesions of bacillary angiomatosis, six (35%) had symptomatic osteolytic bone lesions that improved following antibiotic therapy. The authors describe the appearance of the bone lesions on radiographs, computed tomographic (CT) scans, magnetic resonance (MR) images, and radionuclide studies. Osteolytic lesions are a relatively common feature of bacillary angiomatosis in patients with HIV infection. The presence of bone lesions aids in differentiation of bacillary angiomatosis from acquired immunodeficiency syndrome-related Kaposi sarcoma, which has similar cutaneous abnormalities but no associated bone lesions.