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Background: Skin and soft tissue infections (SSTIs) are a common complaint in the ambulatory setting and pose a significant burden on the health care system., Objectives: We sought to determine the accuracy of ultrasound for detecting soft tissue abscesses by emergency medicine associate providers (APs)., Methods: This was a prospective observational study of adult patients with suspected SSTI in the emergency department of a rural tertiary care academic medical center. The AP performed and interpreted point-of-care ultrasound (POCUS) of the suspected infected area. Ultrasound images and interpretation were reviewed by the attending emergency physician with either rejection or agreement of the image interpretation, diagnosis, and management. If incision and drainage was performed, presence or absence of purulent drainage was recorded., Results: Sixty-four patients with suspected SSTI were enrolled: 29 had POCUS-proven abscesses and 33 had cellulitis; 2 were excluded. AP clinical evaluation alone for identifying abscess revealed sensitivity of 92.3 (74.9-99.1), specificity of 67.7 (49.5-82.6), positive predictive value of 68.6 (57.0-78.2), and negative predictive value of 92.0 (81.4-100). The use of POCUS by APs in addition to clinical examination demonstrated sensitivity of 96.2 (80.4-99.9), specificity of 93.9 (79.8-99.3), positive predictive value of 92.6 (76.5-98.0), and negative predictive value of 96.9 (81.9-99.5). p values were <0.05 for test characteristics. Ultrasound results changed SSTI management decisions in 10 of 62 (16.1%) patients, with the most common change being a new incision and drainage or needle aspiration. Agreement of the POCUS interpretation between APs and attending physicians was 96.8% with a κ of 0.94 (0.85-1.00)., Conclusion: With modest training, APs can successfully use POCUS to identify abscesses in patients in the emergency department with SSTIs. POCUS increases the ability to rule in the diagnosis and changes management in a clinically relevant number of patients with SSTIs., (Copyright © 2020. Published by Elsevier Inc.)

Purpose of Review: To highlight recent contributions in the literature that enhance our understanding of the cutaneous immune response to allergen., Recent Findings: Defects in skin barrier function in infancy set the stage for the development of atopic dermatitis (AD) and allergy. Both genetic and environmental factors can contribute to damage of the stratum corneum (SC), with activation of specific protease enzymes under high pH conditions playing a key role. Immune cells and mediators in the dermis and epidermis impair SC repair mechanisms and support allergy development. In barrier-disrupted skin, type 2 innate lymphoid cells (ILC2s), mast cells (MCs), and basophils have been shown to promote AD and pathogenic Th2 responses in murine models. Skin barrier disruption favors induction of systemic Th2-associated inflammatory pathways. A better understanding of the ontogeny and regulation of these complex networks in infant skin is needed to guide future strategies for allergy treatment and prevention.

Purpose of Review: This second part of the article aims to highlight recent contributions in the literature that enhance our understanding of the cutaneous immune response to allergen., Recent Findings: Several properties of allergens facilitate barrier disruption and cutaneous sensitization. There is a strong epidemiologic relationship between the microbiome, both the gut and skin, and atopic dermatitis (AD). The mechanisms connecting these two entities remain enigmatic; however, recent murine models show that commensal skin bacteria play an active role in supporting skin barrier homeostasis and defense against microbial penetration. Likewise, the association between the lack of colonization with Staph species and AD development suggests a potentially functional role for these organisms in regulating the skin barrier and response to environmental allergens. In undisrupted skin, evidence suggests that the cutaneous route may promote allergen tolerance. Properties of environmental allergens and commensal bacteria add to the complex landscape of skin immunity. Further investigation is needed to elucidate how these properties regulate the cutaneous immune response to allergen.

Between October of 1983 and June of 1985, 31 patients underwent primary breast reconstruction with tissue expansion. Tissue expansion was utilized for breast reconstruction when the remaining muscle and skin following modified radical mastectomy was insufficient to accommodate a prosthesis that matched in size and shape the opposite breast. All expanders were placed beneath an investing muscular pocket created by elevating the pectoralis major and serratus anterior. Postoperative expansion began within 1 week, and the breast was expanded to double the volume of the opposite breast. Twenty-two patients have completed their reconstruction with a mean follow-up in 7 months. There were nine complications, including five deflations and four infections. All patients have remained Baker I or Baker II. Creating ptosis to match the breast was accomplished by placing the expander below the rectus fascia and superiorly advancing this expanded tissue at the time of prosthesis placement. Primary breast reconstruction with tissue expansion following modified radical mastectomy is safe, simple, and produces a breast with excellent shape, size, texture, and patient satisfaction.

Curran, Harold R. (U. S. Department of Agriculture, Washington, D. C.) and Georges Knaysi. Survey of fourteen metabolic inhibitors for their effect on endospore germination in Bacillus subtilis. J. Bacteriol. 82:793-797. 1961.-Phase contrast microscopy was used to study the effects of metabolic antagonists upon incipient spore germination in glucose agar-film microcultures. The period of observation was 1 to 2 hr. Of 14 compounds tested, only ethanol in 10% concentration (v/v) caused almost complete inhibition. Oxamic acid and dl-ethionine were slightly stimulatory; 6-methyl thiouracil and octyl aldehyde were without effect. The inhibiting effect of the remainder depended upon the concentration of the antagonist. The stimulating effect of glucose on germination is discussed.

Knaysi, Georges (Cornell University, Ithaca, N.Y.). Further observations on the spodogram of Bacillus cereus endospore. J. Bacteriol. 90:453-455. 1965.-Endospore spodograms of Bacillus cereus C(3) were examined in dark contrast by use of the phase microscope with oil-immersion objectives. When the spodograms were mounted in air, their central part, or core, appeared bright; when mounted in water or oil, the central part appeared dark. The central part of the normal, unincinerated spore appeared bright in air and water, but dark in oil. This indicated that whether a body appears bright or dark when observed with the phase microscope does not depend only on its refringence relative to that of its surround, but also on its thickness and on the magnitude of the difference between its refractive index and that of its surround. Present observations showed that, contrary to a previous conclusion, mineral matter is more highly concentrated in the core than at the periphery of the endospore.

Knaysi, Georges (Cornell University, Ithaca, N. Y.) and Harold R. Curran. Effects of some mechanical factors on the endospores of Bacillus subtilis. J. Bacteriol. 82:691-694. 1961.-Phase contrast microscopy was used to study incipient spore germination and early growth under conditions involving agitation with a platinum wire loop, sonic oscillation, and freezing and thawing. Treatment resulted in change in optical properties and destruction of a certain proportion of the spores. Up to one-tenth of the spores was destroyed by loop agitation. Sonic oscillation had little apparent effect upon incipient germination (darkening) of the spores, but subsequent development involving growth was stimulated in a considerable proportion. The effect of freezing and thawing upon incipient germination is discussed.

Knaysi, Georges (Cornell University, Ithaca, N. Y.). Determination, by spodography, of the intracellular distribution of mineral matter throughout the life history of Bacillus cereus. J. Bacteriol. 82:556-563. 1961.-The intracellular distribution of mineral matter throughout the life history of Bacillus cereus strain C(3) was investigated by microincineration for which the term spodography is suggested. The organism was grown in microcultures on collodion membranes supported by agar media. At various stages of development, microcultures were floated on distilled water, picked onto cover glasses, air-dried, and incinerated at 500 to 525 C. The mineral residue is deposited in situ and shows the distribution of mineral matter in the cells. Study of the spodograms thus obtained shows that in the spore mineral matter is concentrated in a peripheral layer surrounding a minerally poor core. As soon as the spore begins to germinate, often before one notes any change in its optical properties, the minerally rich layer increases in thickness while the core becomes gradually smaller and finally disappears. The germ cell appears nearly homogeneous, with evidence of mineral aggregation into discrete granules more readily seen in subsequent generations. The nuclei of the vegetative cells are sites of mineral accumulation. In the compound nuclei, minerals seem to be concentrated in a superficial ring around a minerally poor center. In the young forespore, mineral matter is homogeneously distributed. As the spore stage is approached, however, the mineral matter tends to occupy a peripheral position as in the completed spore. The results indicate that the calcium dipicolinate of the spore is principally in the minerally rich, peripheral layer. The relation of this layer to the other peripheral structures of the spore has not been determined. Observation was made with a phase microscope in dark contrast and using a dry objective.