What's hot?
What's hot
May 29, 2018
In this monthly column, members of the Dermatology World Editorial Advisory Workgroup identify exciting news from across the specialty.
Edward W. Cowen, MD, MHSc
You may be surprised to learn that a new organ’ in the skin was recently identified. In a recent issue of Scientific Reports an advanced imaging technique called confocal laser endomicroscopy’ was used to define a structure in the skin and other tissues they term the interstitium’ (2018 Mar 27;8(1):4947). The interstitium is composed of fluid-filled spaces between collagen bundles in the dermis lined by fibroblast-like CD34+ cells, which form a matrix of inter-connected spaces. Similar spaces are found in the fascia and in numerous visceral organs such as the intestine, stomach and gall bladder. The authors propose that these pre-lymphatic’ spaces may play a protective role in shock absorption of organs which undergo compression and distension (e.g. lungs, bladder) or tissues exposed to mechanical injury (e.g. dermis, muscle fascia). They further speculate that the interstitium could play a key role in the development of interstitial edema or metastasis along submucosal/dermal plane, and as precursors of myofibroblasts that could lead to sclerosis of the skin and esophagus in scleroderma.
Morphea, eosinophilic fasciitis (Shulman syndrome), and chronic graft-versus-host disease (GVHD) involving the fascia are debilitating and poorly understood conditions. It is intriguing to hypothesize that the physical stress that precipitates Shulman syndrome, or isomorphic sclerotic lesions in morphea or GVHD, could be triggered by a failure of shock absorption’ of the interstitium. Although the Scientific Reports paper has received significant coverage in the lay press based on the claim of a new organ,’ the Fascia Research Society has held meetings devoted to understanding this nebulous tissue for over a decade. Much work remains to better understand the functional significance of this new organ.’
Deepti Gupta, MD
Gentamicin is an aminoglycoside antibiotic that has a broad antimicrobial spectrum of action and has recently been described in the treatment of genetic disorders, specifically those with a nonsense mutation (J Invest Dermatol. 2018 Apr;138(4):731-734). In 2017, Woodley et al performed a double-blind placebo-controlled trial looking at topical gentamicin 0.1% ointment and intradermal gentamicin in 5 patients with recessive dystrophic epidermolysis bullosa (RDEB), and found with three times a day application for 2 weeks to open erosions there was improved wound closure, reduced blister formation, and correction of the dermal-epidermal separation as compared to placebo (J Clin Invest. 127(8): 3028-3038). At sites of application, restored full-length and functional type VII collagen was present and persisted for at least 3 months. At the 2018 AAD Annual Meeting they presented their recent work looking at topical gentamicin 0.5% ointment and found increased levels of restored collagen type VII (38-50% vs 20%) as compared to 0.1%. There were no adverse side effects observed in these studies. The use of topical gentamicin has been investigated in other genetic disorders including Hailey-Hailey, xeroderma pigmentosum, and Nagashima-type palmoplantar keratoderma, which showed some improvements in hyperkeratosis. Topical gentamicin may be a promising new treatment for certain genetic skin disorders.
Christen Mowad, MD
The American Contact Dermatitis Society announces an allergen of the year annually. This year’s contact allergen is propylene glycol (Dermatitis 29(1): 3-5, 2018). Propylene glycol is an emollient and emulsifier found in many personal care products, medications, and even food. It is found widely in these products and has been reported to cause both irritant and allergic contact dermatitis as well as systemic reactions. Patch testing can be tricky as the irritant reaction sometimes seen can be difficult to differentiate from a weak reaction. This has also caused controversy over the significance of positive reactions and how they should be interpreted. The most common site for propylene glycol contact dermatitis according to the North American Contact Dermatitis Group is the face (25.9%) followed by a scattered/generalized pattern (23.7%). The prevalence of a reaction to this allergen also varies depending on what the testing concentration is and ranges from 0.8%- 3.5%. Personal care products were the most common source of propylene glycol with topical steroids being the next most likely source. Propylene glycol was not commonly found to be the cause of an occupational contact dermatitis. Given that propylene glycol is found extensively in the products patients use including prescription medications, as well as the foods they ingest, it is important that dermatologists be aware of this allergen, screen for it and manage it appropriately.
Corey Hartman, MD
The effects of platelet rich plasma (PRP) therapy are maintained with concomitant medical treatment for androgenetic alopecia.
By now, it is widely accepted that the benefits of PRP therapy on hair density in androgenetic alopecia (AGA) are noticeable and reproducible. Though the exact mechanism is not known, it likely involves the release of several growth factors from platelets with receptors on the hair follicle. Previous studies have shown the efficacy of PRP as monotherapy, but studies that evaluate the benefits of topical and oral medical treatment have been lacking until now.
In a new study conducted at New York University Department of Dermatology, 24 patients were retrospectively evaluated who had undergone PRP treatments in combination with either topical minoxidil 5%, finasteride (the only two FDA-approved treatments for AGA), spironolactone, dutasteride, or flutamide (J Am Acad Dermatol. doi: 10.1016/j.jaad.2018.03.022. [Epub ahead of print]). After baseline trichologic assessments at the crown of the scalp were taken for hair density and diameter, PRP treatments were administered monthly for two consecutive months. If hair density increased more than 10%, monthly treatments were continued for four more months and then maintenance injections every 3-6 months.
All patients used topical minoxidil 5% and 83.3% used an oral antiandrogen medication as well. Positive response to PRP was seen in 70.8% of patients after two month initial injections. Hair density increased at a statistically significant level while changes in hair shaft diameter did not reach statistical significance.
Christopher Messana, DO, JD
The Multicenter Selective Lymphadenectomy Trial (MSLT-1) was the first randomized trial of SLNB conducted (N Engl J Med. 2014;370(7):599-609). Its authors declared sentinel lymph node status the most powerful’’ prognostic indicator for melanoma, leading to the procedure’s routine use and adoption in staging guidelines. Freeman et al were the first to specifically examine prognosis of SLN status stratified by Breslow thickness (BT) (Dermatol Surg. 2013;39(12):1800-1812). Only tumors thicker than 4 mm were found to be associated with statistically significant survival difference between SLN-positive and SLN-negative patients, whereas a survival difference was not seen for tumors with a BT of 4 mm or less.
A group of researchers from the Cleveland Clinic recently conducted a retrospective cohort study of patients from their institution who underwent SLNB for cutaneous melanoma, examining whether further prognostic information is gained by determining SLN status beyond that known from BT alone (J Am Acad Dermatol. 2018;78(5):942-948). In their study, 7.7% of patients with tumors 1 mm or less had a positive SLN. In their subset of 326 patients with thin melanomas, a statistically significant survival difference based on SLN status was not observed (albeit with a median follow-up time of 30.3 months). This information, combined with the knowledge that survival with thin melanoma is excellent regardless of SLN status, should be acknowledged when counseling patients.
This important study suggests that SLN status may not add prognostic value for patients with melanoma of BT less than 4 mm, especially those with thin melanomas, underscoring the difficulty we face in making a concise, decisive recommendation as to SLN biopsy to most of our patients.
Michel McDonald, MD
Patients treated with Mohs micrographic surgery (MMS) for melanoma of the face have similar melanoma-specific mortality compared with patients treated with other forms or surgical excision (Dermatol Surg. 2018;44:481-492). A total of 43,443 patients with melanoma of the face were included for review. Overall, 14% of these patients were treated with MMS. Although most MMS was performed for lentigo maligna, almost one quarter of tumors treated with MMS were invasive. In a subgroup analysis melanoma specific 5-year mortality risk of invasive melanoma treated with narrow margin excision or wide margin excision did not differ from the risk in patients treated with MMS. While the study has limitations including the lack of data regarding other treatment modalities such as immunotherapy or chemotherapy and randomized controlled trials would be preferable, it does support MMS as an equivalent treatment modality to narrow or wide margin excision.
