Implications for cumulative and prolonged clinical improvement induced by cross-linked hyaluronic acid: An in vivo biochemical/microscopic study in humans.

In photoaged human skin, type I collagen fragmentation impairs dermal extracellular matrix (ECM) integrity, resulting in collapsed/contracted fibroblasts with reduced type I procollagen synthesis. Injections of cross-linked hyaluronic acid (CL-HA) reverse these deleterious changes. To investigate the time course and effects of biochemical changes induced by injected CL-HA, particularly whether fibroblast activation leads to accumulation/deposition of dermal collagen, we injected CL-HA into photoaged skin of human participants over 60 years-old and performed biochemical/microscopic analyses of skin samples. Beginning 1 week post-injection and lasting 6-9 months, fibroblasts exhibited activation, including increased immunostaining and gene expression of markers of type I collagen synthesis, such as heat shock protein 47 and components of the transforming growth factor-ß pathway. At 1 week post-injection, multiphoton microscopy revealed elongation/stretching of fibroblasts, indicating enhanced dermal mechanical support. At 4 weeks, second-harmonic generation microscopy revealed thick collagen bundles densely packed around pools of injected CL-HA. At 12 months, accumulation of thick collagen bundles was observed and injected CL-HA remained present in substantial amounts. Thus, by occupying space in the dermal ECM, injected CL-HA rapidly and durably enhances mechanical support, stimulating fibroblast elongation and activation, which results in thick, densely packed type I collagen bundles accumulating as early as 4 weeks post-injection and continuing for at least a year. These observations indicate that early and prolonged clinical improvement following CL-HA injection results from space-filling and collagen deposition. As type I collagen has an estimated half-life of 15 years, our data provide the foundations for optimizing the timing/frequency of repeat CL-HA injections.

Development of an Illustrated Scale for Acute Radiation Dermatitis in Breast Cancer Patients.

PURPOSE: Scales for rating acute radiation dermatitis (ARD) have not been validated despite decades of clinical use, and little is known regarding the relationship between toxicity scores and patient-reported symptoms. Skin tone also complicates assessment of ARD, and as such we sought to design an illustrated scale to consistently describe ARD across several skin tone types in breast cancer patients undergoing radiation (RT). METHODS AND MATERIALS: Patients undergoing RT for breast cancer were enrolled on a prospective study with photographs obtained at 2-week intervals. Photographs were clustered according to the apparent severity of acute radiation dermatitis and a descriptive photonumeric scale was developed. Four clinically experienced raters used both the illustrated photonumeric scale and the Common Terminology Criteria for Adverse Events to independently score the collection of photographs in 2 independent sessions. RESULTS: Among 80 unique patients with 192 photographs, 47 patients (59%) completed questionnaires about their symptoms during RT. Physicians completed toxicity forms at the point-of-care for 52 patients (65%). Photonumeric ratings compared against patient reports of dry and moist desquamation demonstrated high specificity (95% and 93%, respectively) and negative predictive value (84% and 92%), indicating correct identification of patients who did not report dry or moist desquamation. The sensitivity and positive predictive value for separate measures of dry and moist desquamation were considerably lower. A combined measure of any desquamation (dry or moist) portrayed higher diagnostic accuracy, resulting in 72% sensitivity, 93% specificity, 75% positive predictive value, and 92% negative predictive value. Photonumeric ratings of dry or moist desquamation were significantly associated with patient reports of itching, burning or stinging, hurting, and swelling. CONCLUSIONS: The Michigan scale for acute radiation dermatitis is a simple grading rubric that is distinguished by characterization of its intra- and interrater reliability and diagnostic accuracy, correlation with patient-reported symptoms of bother and pain, and applicability across the spectrum of skin pigmentation.

Perioral wrinkles are associated with female gender, aging, and smoking: Development of a gender-specific photonumeric scale.

BACKGROUND: Perioral wrinkling is commonly reported among older adults, but its objective evaluation and causes remain poorly understood. OBJECTIVE: We sought to develop a photonumeric scale for perioral wrinkling and to elucidate contributory lifestyle factors. METHODS: In this cross-sectional study, we recruited participants for facial photographs and a survey. A gender-specific photonumeric scale for perioral wrinkling was developed and used by 3 graders to evaluate participant photographs. Scores and survey responses were used to create a multiple regression model to predict perioral wrinkling. RESULTS: In all, 143 participants aged 21 to 91 years were enrolled. Intraclass correlation coefficient values for interrater and intrarater reliability were high (>0.8) across 2 trials and 3 graders. A multiple regression model for prediction of perioral wrinkling severity included age, gender, and years of smoking as variables. LIMITATIONS: The study was limited by sample size and a predominantly Caucasian study population. CONCLUSION: We created a photonumeric scale that accounts for gender differences in perioral wrinkling and highlighted contributory variables to photoaging in this anatomical location.

Case series of volar juvenile xanthogranuloma: clinical observation of a peripheral rim of hyperkeratosis.

Juvenile xanthogranuloma is a benign histiocytic tumor predominantly occurring in children as yellowish papules on the head and trunk. Presentations on the volar surfaces are rare and may cause diagnostic confusion with pyogenic granuloma, eccrine poroma and digital fibrokeratoma. We report two patients with unusual presentations of solitary juvenile xanthogranuloma on the palm or sole. Both had lesions lacking the classic yellowish color and demonstrating a well-defined, peripheral hyperkeratotic rim. Histopathological evaluation revealed prominent orthokeratosis corresponding to the rim. Additional histological features, including dermal histiocytes and Touton giant cells, were consistent with the diagnosis of juvenile xanthogranuloma. Given the unusual locations and colors of the lesions, we conclude that histopathological evaluation is central to diagnosing volar juvenile xanthogranuloma. We additionally suggest that juvenile xanthogranuloma should be included in the differential diagnoses of volar lesions displaying a peripheral hyperkeratotic rim.

Keratin 79 identifies a novel population of migratory epithelial cells that initiates hair canal morphogenesis and regeneration.

The formation of epithelial tubes underlies the development of diverse organs. In the skin, hair follicles resemble tube-like structures with lumens that are generated through poorly understood cellular rearrangements. Here, we show that creation of the hair follicle lumen is mediated by early outward movement of keratinocytes from within the cores of developing hair buds. These migratory keratinocytes express keratin 79 (K79) and stream out of the hair germ and into the epidermis prior to lumen formation in the embryo. Remarkably, this process is recapitulated during hair regeneration in the adult mouse, when K79(+) cells migrate out of the reactivated secondary hair germ prior to formation of a new hair canal. During homeostasis, K79(+) cells line the hair follicle infundibulum, a domain we show to be multilayered, biochemically distinct and maintained by Lrig1(+) stem cell-derived progeny. Upward movement of these cells sustains the infundibulum, while perturbation of this domain during acne progression is often accompanied by loss of K79. Our findings uncover previously unappreciated long-distance cell movements throughout the life cycle of the hair follicle, and suggest a novel mechanism by which the follicle generates its hollow core through outward cell migration.

Rapid clinical change in lesions of atypical cutaneous lymphoproliferative disorder in an HIV patient: a case report and review of the literature.

BACKGROUND: HIV associated atypical cutaneous lymphoproliferative disorder (ACLD) is a rare condition characterized by a pruritic, often generalized, eruption of patches and plaques or erythroderma clinically simulating mycosis fungoides (MF) or Sézary syndrome. A polyclonal CD8+ T-cell infiltrate on biopsy can help differentiate ACLD from MF or Sézary syndrome, but the clinical and histopathologic appearance must also be considered. Accurate diagnosis is imperative because HAART therapy has been reported to improve this condition in some patients. OBSERVATION: We report a case of HIV associated ACLD, with an atypical presentation, initially consisting of diffuse papules, some with a dusky targetoid center. Two weeks after starting antiviral therapy the papules flattened, evolving to xerotic, hyperpigmented macules. CONCLUSION: The working-theory of a reactive etiology for this condition might explain the evolution in appearance following initiation of HAART. The presence of papules with a dusky targetoid center suggests that this condition should be considered in the differential diagnosis with syphilis or atypical erythema multiforme in HIV patients.

Two cases of syringotropic cutaneous T-cell lymphoma and review of the literature.

Syringotropic cutaneous T-cell lymphoma (CTCL) is a rare form of CTCL characterized histologically by infiltrates of atypical lymphocytes located primarily in and around hyperplastic eccrine glands and ducts. Currently, syringotropic CTCL is classified as a histopathologic variant of folliculotropic mycosis fungoides (MF); however, the relationship between these two entities remains tenuous. We report two additional cases of syringotropic CTCL and review the differences between these two subtypes of MF with regard to epidemiology, clinical features, prognosis, and treatment. Based on these data, we conclude that syringotropic CTCL should be classified as a distinct variant of MF separate from folliculotropic MF.

Computer-assisted alignment and tracking of acne lesions indicate that most inflammatory lesions arise from comedones and de novo.

BACKGROUND: Inflammatory acne lesions are believed to derive from comedones; however, their evolution has not been rigorously studied. OBJECTIVE: To examine the evolution of facial acne lesions using serial digital photographs and spatial alignment software. METHODS: Six predefined lesion types, including inflammatory lesions, were counted and tracked from photographs taken every 2 weeks for 12 weeks from 25 individuals with untreated facial acne. RESULTS: Closed comedones occurred most frequently (37%), followed by erythematous macules (26%), inflammatory papules (15%), open comedones (12%), pustules (2%), and nodules (1%). Inflammatory lesions were preceded by comedones (54%), normal-appearing skin (28%), erythematous macules (12%), and scars (6%). LIMITATIONS: Lesions could have appeared and resolved within the 2-week intervals and some comedones may have been too small to identify on digital photographs. CONCLUSION: Our results confirm the comedonal origin of the majority of inflammatory acne lesions. However, a sizeable number (28%) appear to arise from normal skin.