This month’s news from across the specialty
What’s hot
March 1, 2023
In this monthly column, members of the DermWorld Editorial Advisory Workgroup identify exciting news from across the specialty.
New, but not new, but maybe new, but not good = Candida auris is looking worse with each additional study. Since it was first described in 2009, C. auris has now been reported in most states in the U.S. It has been a nationally notifiable pathogen in the United States since 2018. Proper diagnosis is complicated by misidentification by traditional testing, but genetic testing is increasingly accurate. The pandemic appears to have increased the spread of the fungal pathogen or at least increased our detection and understanding. Watkin et al recently published an update on C. auris that reviews key new details about C. auris and the skin (Pathogens and Immunity. 2022; 7(2): 46-65. doi: 10.20411/paiv7i2.535). This pathogen can persist on the skin and the surfaces of health care facilities. Many nursing home residents are chronically colonized with C. auris. Most clinical cleaning agents have limited impact on growth and do not decrease spread. Invasive infections and candidemia are highly resistant to our antifungal drugs and are associated with high mortality rates. Best practices for minimizing risks continue to evolve. Hand hygiene and aseptic technique are not new, but they are good.
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The highly anticipated 2023 Allergen of the Year designation has been given to lanolin, a complex, fat-like substance derived from wool grease, composed of high molecular weight esters alcohols, fatty acids, sterols, and hydrocarbons. It is used for its emollient properties. Amerchol L-101 is a mixture of 10% lanolin alcohol and mineral oils and is used for patch testing in addition to lanolin 30% alcohols. Some studies state Amerchol may detect more allergy but can also have false-positive reactions due to irritation.
A study by the North American Contact Dermatitis Group looked at patch test reactions when testing to lanolin alcohol 30% or Amerchol L-101 50% in petrolatum and found that of those tested, 3.3% had positive reactions and 84% were felt to be currently relevant. The most common sites were the hands, a scattered generalized distribution, and the face. Lanolin sources are often personal care products, including creams, lipsticks, shampoos, soaps, and topical medications. Other sources include furniture polish, ink, leather, textiles, and waxes. Lanolin allergy is more prevalent in children and is associated with atopy, stasis dermatitis, chronic leg ulcers, and perianal and genital dermatitis. Sometimes patients are patch test positive to lanolin but can tolerate use of lanolin on normal skin — a so-called “lanolin paradox.” Repeat open application testing (ROAT) can be helpful to determine if lanolin patch test positive patients can tolerate lanolin containing products. When seeing patients with contact dermatitis considering lanolin allergy, common lanolin sources, and the lanolin paradox will be useful.
There has never been a better time with so many systemic options to consider in the treatment of psoriasis. A common question asked in clinic is whether a change in systemic treatment can afford even a small but potentially meaningful improvement. I wish I had a crystal ball for these moments!
It is with interest that I read about the PSOARING 3 trial looking into the one-year safety and efficacy of tapinarof cream for psoriasis (doi: 10.1016/j.jaad.2022.06.1171). No topical medication with a novel mechanism of action had been approved by the FDA for over the past two decades. I thought to myself: Perhaps this new topical prescription could have prevented premature changes in biologic therapy.
Tapinarof is a small-molecule topical aryl hydrocarbon receptor (AhR) agonist. It binds and activates AhR, leading to downregulation of proinflammatory cytokines, including interleukin IL-17A and IL-17F. Patients from the PSOARING 1 and PSOARING 2 clinical trials that led to FDA approval were eligible to enroll in PSOARING 3, a 40-week extension of open label treatment. Of note, nail, palmoplantar, and scalp involvement were not assessed in this study, and 84.3% of study participants were white.
91.6% enrolled (n=763). 40.9% of patients achieved complete disease clearance, or Physician Global Assessment (PGA) = 0. 58.2% entering with PGA ≥ 2 achieved PGA = 0 or 1. In this study, the forced-withdrawal design resulted in intermittent treatment mimicking real-world experience. Patients achieving complete clearance had treatment discontinued and were re-treated when PGA score increased to 2 or greater. Mean time off therapy for patients achieving PGA = 0 was just over four months! No new safety signals were observed; the two most common adverse events were folliculitis (22.7%) and contact dermatitis (5.5%). Multiple factors influence the therapeutic decision-making process. We now have new options to consider for recalcitrant psoriasis!
More What’s Hot!
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Since the original definition of Laugier-Hunziker syndrome as a rare disorder of oral mucosal hyperpigmentation and melanonychia striata that is exclusively seen in Caucasians, the literature has been replete with case reports and case series of this extremely rare entity. In many of these publications, the patients have darker skin, which does not fit the original definition of this syndrome. It is not uncommon for darker-skinned patients to have oral mucosal pigmentation and melanonychia striata. In fact, physiologic pigmentation is the most common cause of multi-focal or diffuse oral mucosal pigmentation (Dent Clin North Am. 2013;57(4):699-710). Melanonychia striata is also very commonly encountered in darkly pigmented races, including Blacks, Asians, Middle-Easterners, and Hispanics. The incidence reportedly varies from 1% in whites, 10%-20% in Asians, and 77-100% in African Americans (Indian Dermatol Online. 2020; 11(1): 1–11). Before diagnosing a darkly pigmented patient with Laugier-Hunziker syndrome (a zebra), one should first consider physiologic pigmentation (a horse) as the much more likely diagnosis.
