The Skin Barrier and Moisturization: Function, Disruption, and Mechanisms of Repair

BACKGROUND

The anatomic layers of the skin are well-defined, and a functional model of the skin barrier has recently been described. Barrier disruption plays a key role in several skin conditions, and moisturization is recommended as an initial treatment in conditions such as atopic dermatitis. This review aimed to analyze the skin barrier in the context of the function model, with a focus on the mechanisms by which moisturizers support each of the functional layers of the skin barrier to promote homeostasis and repair.

SUMMARY

The skin barrier is comprised of four interdependent layers - physical, chemical, microbiologic, and immunologic - which maintain barrier structure and function. Moisturizers target disruption affecting each of these four layers through several mechanisms and were shown to improve transepidermal water loss in several studies. Occlusives, humectants, and emollients occlude the surface of the stratum corneum (SC), draw water from the dermis into the epidermis, and assimilate into the SC, respectively, in order to strengthen the physical skin barrier. Acidic moisturizers bolster the chemical skin barrier by supporting optimal enzymatic function, increasing ceramide production, and facilitating ideal conditions for commensal microorganisms. Regular moisturization may strengthen the immunologic skin barrier by reducing permeability and subsequent allergen penetration and sensitization.

KEY MESSAGES

The physical, chemical, microbiologic, and immunologic layers of the skin barrier are each uniquely impacted in states of skin barrier disruption. Moisturizers target each of the layers of the skin barrier to maintain homeostasis and facilitate repair.

Primary Tumor Location Predicts Survival in Melanoma: A Retrospective Cohort Study of 239,257 Melanoma Patients

The link between primary tumor location and overall survival in melanoma has been studied in the past, but its associated population and prognostic significance is less understood. The purpose of this study was to characterize melanoma demographics and disease-specific survival (DSS) in relation to primary tumor site. Data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program were retrospectively analyzed; from 1973 to 2015, 239,257 patients diagnosed with cutaneous melanoma were included in the study and separated into three cohorts based on primary tumor site. The effect of primary location on melanoma survival was evaluated using Cox proportional hazards models. Tumors were predominantly localized and had a depth of ≤1 mm. Patients diagnosed with tumors originating in the upper and lower extremities had significantly increased DSS probability compared to those of the head and neck. Characteristics, including woman sex, married or widowed status, treated on the Pacific coast, and increasing year of diagnosis, were associated with greater DSS. Conversely, non-white or Hispanic origin, higher age at diagnosis, tumors with increased depth, or nodular or acral melanoma histology were associated with lower DSS. Primary tumor site is a significant predictive factor of DSS in cutaneous melanoma along with additional characteristics supported in our study.

Combined antibiotic, steroid, and moisturizer for atopic dermatitis: A two-year case series of patient-reported outcomes

BACKGROUND

Eczema treatments that target Staphylococcus aureus include topical mixtures of antimicrobial agent and corticosteroid diluted in a moisturizer base, previously described in the literature as compounded antibacterial, steroid, and moisturizer (CASM). There have been no placebo-controlled blinded studies of CASM. Thus, patient-reported outcome data may prove valuable.

OBJECTIVE

To determine the patient-reported clinical course of eczema treatment with CASM.

METHODS

Longitudinal case series between May 2016 and August 2018 of CASM patients/parents. Patients completed surveys including the POEM measure at start of treatment, 1 week, 2 weeks, 1 month, 3 months, 6 months, 9 months, and 12 months thereafter. Response curves were fitted to severity measures over time and compared by patient age group; survival analysis was used to estimate time-to-clear status as a function of patient age and initial severity.

RESULTS

A total of 2153 reports were received from 728 unique respondents with a median patient age of 7 and range of 0-85. Response curves showed significant improvement over time leading to plateaus between 30 and 60 days of treatment. Overall mean improvement between start and day 90 for POEM was 14.3 (from 20.0 [95% CI 11.4-28.8] to 5.7 [95% CI -3.2 to 14.8]). Improvement was seen in each age group.

CONCLUSIONS

Patient-reported outcomes suggest efficacy of CASM. There were large reductions in POEM scores, mostly in the first 30 days of treatment for all age groups.

Drug eruptions associated with tumor therapy: Great imitators

Many studies have investigated cutaneous reactions to antitumor drugs and found them to be quite numerous. We describe drug eruptions that may be associated with different therapies by class: antimetabolite chemotherapeutics, genotoxic agents, spindle inhibitors, signal transduction inhibitors, and immunotherapies. Methotrexate is most often associated with mucocutaneous reactions, alkylating antimetabolite agents with hyperpigmentation, and platinum antimetabolite agents with type I IgE-mediated hypersensitivity reactions. Anthracycline derivatives can induce the hand-foot syndrome in patients, and bleomycin is associated with a bleomycin-induced flagellate erythema. Taxane spindle inhibitors can result in acneiform eruptions, which may also be seen with use of epidermal growth factor receptor inhibitors. Imatinib and its derivatives can cause a truncal maculopapular eruption, whereas multikinase inhibitors can produce a hand-foot-skin reaction. Vemurafenib can result in squamous cell carcinomas and photosensitivity. First-generation mammalian target of rapamycin inhibitors may cause a maculopapular eruption initially involving the face and neck. Programmed death (PD)-1-ligand and receptor inhibitors are associated with bullous pemphigoid. Ipilimumab, targeting Cytotoxic -T- Lymphocyte- associated (CTLA-4) receptors, can cause a morbilliform reaction, whereas Interleukin -2 (IL-2) analogs can create the capillary leak syndrome. Chemotherapeutic drug eruptions classically can manifest in the aforementioned ways; however, it is important to understand that they are associated with myriad cutaneous adverse effects, which may be mistaken for organic skin disease. Oncologists prescribing these medications should be familiar with the cutaneous side effects of these medications, and so they may counsel patients to be on the lookout for them.

Pyoderma gangrenosum with pure red cell aplasia

Pyoderma gangrenosum is an inflammatory condition of the skin commonly associated with inflammatory bowel disease and rheumatoid arthritis, but also associated with various hematological malignancies. We describe its association with pure red cell aplasia in a four year old boy who presented with progressive skin lesions, fever and pallor, and improved with corticosteroid therapy.