Extramammary Paget disease. Part II. Evidence-based approach to management.

Extramammary Paget disease is a rare cutaneous malignancy that most commonly affects the genitals, perianal area, and axilla of elderly patients. Delays in care often lead to high levels of disease burden for patients. Thus, evidence-based recommendations are paramount in mitigating morbidity and mortality for this unique patient population. This 2-part continuing medical education series provides a complete picture of extramammary Paget disease. Part 2 of this continuing medical education series focuses on the complex management of extramammary Paget disease including surgical and noninvasive therapies, as well as novel approaches for advanced disease.

Extramammary Paget disease. Part I. epidemiology, pathogenesis, clinical features, and diagnosis.

Extramammary Paget disease (EMPD) is a rare skin cancer of apocrine-rich skin that mimics common inflammatory and infectious dermatoses, leading to delays in diagnosis and increased patient morbidity. Better clinical recognition of this entity, multidisciplinary patient assessment, and deeper understanding of the underlying pathophysiology are essential to improve patient care and disease outcomes. It is important to distinguish primary intraepithelial/micro-invasive EMPD from invasive EMPD or cases with adenocarcinoma arising within EMPD. This 2-part continuing medical education series provides a complete picture of EMPD. Part 1 of this continuing medical education series reviews the epidemiology, oncogenesis, clinical and histopathologic presentation, workup, and prognosis of this rare cancer.

Comparing the Efficacy for Pulse Versus Continuous Dose Terbinafine Therapy in Patients With Onychomycosis.

Recently, treatment outcomes in patients with toenail onychomycosis have improved considerably due to more effective oral antifungal medications such as terbinafine and itraconazole. These medications can either be used continuously for several weeks at a lower dose or intermittently (pulsed) at a higher dose. Previous literature comparing pulse and continuous therapy has generated mixed results.  Our study aims to compare the efficacy, in terms of clinical cure rate, of continuous vs pulse dose terbinafine regimens for toenail onychomycosis. Sixty patients with onychomycosis of Fitzpatrick skin types IV to VI, between 15 and 65 years of age, were divided into a continuous treatment group receiving 250 mg terbinafine once daily for 12 weeks and a pulse treatment group receiving 250 mg twice daily terbinafine for 1 week repeated every 4 weeks for 12 weeks. Each patient was followed up at weeks 4, 8, and 12.  Efficacy of the continuous treatment group was significantly greater at 76.67% compared with 26.67% in the pulse treatment group. Thus, we conclude that the clinical cure rate of a continuous dose regimen of terbinafine is a superior treatment option for toenail onychomycosis. However, we also suggest further studies including combinations of multiple agents and hybrid regimen models for the optimal onychomycosis treatment.   J Drugs Dermatol. 2023;22(10):     doi:10.36849/JDD.7323R1.

Lichen planus pemphigoides: A unique form of bullous and lichenoid eruptions secondary to nivolumab.

The widespread use of PD-1 inhibitors to treat various solid tumors has brought certain challenges for the clinician, including immune-related adverse events (irAEs). Cutaneous toxicities are among the most observed irAEs. Bullous and lichenoid dermatoses following PD-1 inhibitor therapy have been described. Here we report a novel case of lichen planus pemphigoides, featuring characteristics of both bullous pemphigoid and lichen planus, in a patient treated with nivolumab for renal cell carcinoma. We subsequently review all three cutaneous conditions which may arise in the context of PD-1 inhibitor therapy.

Scalp microbiome: a guide to better understanding scalp diseases and treatments.

The scalp microbiome represents an array of microorganisms important in maintaining scalp homeostasis and mediating inflammation. Scalp microbial dysregulation has been implicated in dermatologic conditions including alopecia areata (AA), dandruff/seborrheic dermatitis (D/SD), scalp psoriasis (SP) and folliculitis decalvans (FD). Understanding the impact of scalp microbial dysbiosis gives insight on disease pathophysiology and guides therapeutic decision making. Herein we review the scalp microbiome and its functional role in scalp conditions by analysis of metagenomic medical literature in alopecia, D/SD, SP, and other dermatologic disease.Increased abundance of Malassezia, Staphylococcus, and Brevibacterium was associated with SD compared to healthy controls. A higher proportion of Corynebacterium, actinobacteria, and firmicutes are present in AA patients, and lower proportions of Staphylococcus caprae are associated with worse clinical outcomes. Decreased prevalence of actinobacteria and Propionibacterium and increased firmicutes, staphylococcus, and streptococcus are associated with scalp psoriasis. Studies of central centrifugal cicatricial alopecia (CCCA) suggest scalp microbial composition contributes to CCCA's pro-inflammatory status. The most common organisms associated with FD include methicillin-resistant S. aureus and S. lugdunensis. Antifungals have been a mainstay treatment for these diseases, while other alternatives including coconut oils and shampoos with heat-killed probiotics have shown considerable potential efficacy by replenishing the scalp microbiome.

Adapting with the Pandemic: Modified Mohs Micrographic Surgery Using Rim and Deep Margin Technique.

The COVID-19 pandemic has changed many facets of medical care and has resulted in a rise in delayed treatments across all specialties, including cosmetic dermatology. Delayed care for squamous cell carcinomas (SCC) and basal cell carcinoma (BCC) is not only a burden for medical providers, but also confers a risk to patients, as delayed surgeries are associated with increased metastatic risk and tumor size. Mohs micrographic surgery (MMS) delayed by more than one year leads to increased risk of complications, including bleeding and impaired wound healing, especially in the elderly population. To decrease bleeding risks, we have developed a modified MMS technique known as the "rim and deep margin" technique. Here, we present additional cases using this technique to minimize bleeding and operative time for patients with an increased risk of morbidity. This technique has been used successfully in the past for large tumors and can now be used for patients who have faced delay of care, as evidenced by its success during the COVID-19 pandemic.

Muir-Torre Syndrome: A Cutaneous Finding Amidst Broader Malignancies.

Muir-Torre syndrome (MTS) is a rare autosomal dominant genetic condition resulting from microsatellite instability which is caused by mutations in DNA mismatch repair genes. This disorder predisposes individuals to skin tumors and visceral malignancies and may be precipitated in immunocompromised or transplant patients. MTS requires close cancer surveillance for the patient and family because of the tendency to develop aggressive internal malignancies and sebaceous carcinoma. Immunohistochemistry and or genetic testing can confirm the diagnosis of MTS. This review offers an update to the guidelines, diagnosis, and management of MTS while offering a unique perspective on an important but lesser-known syndrome.

Imaging Tools for Noninvasive Hair Assessment.

Trichology tools historically have been limited in their ability to provide noninvasive detailed assessments of the hair and scalp. Recent advances in diagnostic and treatment monitoring technologies have begun to fill this gap. Global photography previously relied on a film camera and stereotactic imaging equipment but has been simplified by the advent of cameras that use software analysis and provide adjustable outlines to match facial features for the capture of standardized views. Reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) both enable in vivo visualization of subcutaneous structures and provide new insight into the dynamic subclinical changes of alopecia. Recent efforts focus on training convolutional neural networks to quantify various hair parameters on OCT scans. When scalp biopsy is necessary, trichoscopy, RCM, and OCT can guide in selecting biopsy sites. Because of the growing clinical applications of these technologies, clinicians should be aware of the advantages and limitations of noninvasive hair-imaging tools.